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Tue05222018

Last updateWed, 27 Sep 2017 1pm

Two planets far outshine all the stars this month. May through June, Venus, at magnitude -4 in the west-northwest at dusk, attains peak altitude of its current apparition and sets a maximum of 2.6 hours after sunset.

Jupiter—magnitude -2.5, its brightest of the year—passes opposition to the sun and all-night visibility on May 8. Watch it climb from very low in the east-southeast at dusk on May 1 to 30 degrees up in the southeast by month’s end.

Next in brilliance at dusk in May are blue-white Sirius (magnitude -1.4) until its departure in the west-southwest, and three zero-magnitude stars: golden-orange Arcturus, high in the east to east-southeast; blue-white Vega, rising into view in the northeast; and yellow Capella, sinking in northwest.

In the morning: Jupiter, in the west-southwest at dawn, is easily the brightest morning “star” until it drops out late in the month. It sets 4-5 minutes earlier each morning, so you can still catch it at month’s end simply by looking before dawn starts to brighten. Next is Mars, hovering in the south while doubling in brightness from magnitude -0.4 to -1.2. Ranking after Mars are Arcturus, sinking in the west to west-northwest; Vega, just northwest of overhead; and Saturn, 15 to 28 degrees west of Mars. Other stars visible include Altair and Deneb, completing the nearly overhead Summer Triangle with Vega; Antares, low in the southwest, below the line joining Jupiter and Saturn; and Fomalhaut, low in the southeast. Mercury, brightening slowly from magnitude +0.4 to -0.6 May 1-21, is very low in the east to east-northeast in dawn twilight. In this poor apparition, binoculars are recommended.

May through July 2018 is a special time for planets! On the morning of May 1, Spaceship Earth is heading toward a direction in space about 17 degrees east (left) of Mars. As our planet follows its nearly circular orbit around the sun, we will overtake all three bright outer planets within 79 days, the shortest interval since 1984, and shortest until 2078. Each body will take its turn at opposition and all-night visibility, starting with Jupiter on May 8.

For events at dawn, we suggest viewing at least one hour before sunrise. For events at dusk, look one hour after sunset.

Tuesday, May 1, at dawn: The moon is in the southwest, just past full, with Jupiter 9 degrees to its lower right. Mars-Saturn are 15 degrees apart in the south. Mercury is rising just north of east. Dusk: Venus and Jupiter are 160 degrees apart.

May 2, at dawn: Antares is 8 degrees to the lower left of the moon. Jupiter 21 is degrees to the moon’s lower right. Dusk: Aldebaran, eye of Taurus, is 6 degrees to the lower left of Venus. Binoculars show the Hyades star cluster in same field as Aldebaran. Together, they form the head of the Bull.

Before this month is over, we’ll lose our views of four of winter’s bright stars as they sink into the western twilight glow. In order of disappearance, they are Rigel, Aldebaran, Sirius and Betelgeuse.

May 3 at dawn: Saturn is 16 degrees, and Mars 32 degrees, to the east (left) of the moon. Through a telescope, the phase of Mars matches the moon’s this morning, 88 percent. The dark marking on Mars known as Syrtis Major appears closest to the center of the Martian disk at 3:43 a.m., and 39 minutes later each successive morning.

May 4 at dawn: Saturn is 4 degrees to the left of the moon. A telescope shows Saturn’s rings tipped nearly 26 degrees from edgewise.

May 5 at dawn: Mars is 9 degrees to the lower left of the waning gibbous moon. Four planets, from Jupiter low in southwest to west-southwest, to Mercury rising just north of east, span 150 degrees.

Sunday, May 6, at dawn: Mars is 3 degrees to the lower right of the moon. Can you detect the bright South Polar Cap, or its cloud cover? Later this month, spring will begin in the Martian southern hemisphere, and the frozen-carbon-dioxide polar cap is near its maximum extent.

May 7 at dawn: The moon, just over half full, is approaching last-quarter phase. Note Mars 14 degrees to the moon’s right.

May 8 at dawn: The moon, in the southeast, is less than 90 degrees west of the sun, so it has passed last-quarter phase and appears as a fat crescent. Find Mars 26 degrees west of the moon. All night: Jupiter is at opposition and visible from dusk until dawn as Earth passes between that planet and the sun.

May 9 at dusk: Venus and Jupiter are within 150 degrees and closing.

May 12 at dawn: The last-day crescent moon is above the horizon one hour before sunrise, just north of east, 5 degrees up, 11 percent full. Dusk: Venus passes 4 degrees south (to the lower left) of second-magnitude Elnath (Beta Tauri, Bull’s northern horn) tonight and tomorrow.

Sunday, May 13: Look about 40 minutes before sunrise to catch the 5-percent crescent old moon just risen 5 degrees north of east. Binoculars may show Mercury 4 degrees to the left of the moon and slightly higher.

May 13-21 at dusk: Look for the red-supergiant star Betelgeuse, shoulder of Orion, 18 degrees to the lower left of Venus. If you look daily at same stage of twilight, Betelgeuse will appear about 1 degrees lower each evening. On what date will you last spot it?

May 16 at dusk: The first crescent moon, 4 percent full, is low in the west-northwest, 11 degrees below Venus.

May 17 at dusk: The crescent moon, 10 percent full, is within 7 degrees to the left of Venus and slightly higher. Telescopes show Venus 84 percent full. Can you still see Betelgeuse? Look 13 degrees to the moon’s lower left.

May 18 at dusk: “Twin” stars Pollux and Castor are 4.5 degrees apart, 10-13 degrees to the upper right of the moon. Venus is 18 degrees to the moon’s lower right. Procyon is 16 degrees to the moon’s left and a little lower.

May 19 at dusk: The twins are 11-16 degrees right of the moon. Procyon is 16 degrees to the moon’s lower left. After dark: Binoculars show the Beehive star cluster within 6 degrees to the moon’s upper left.

Sunday, May 20 at dusk: Venus and Jupiter are 135 degrees apart and closing.

May 21 at dusk: The first-quarter moon is half full. Regulus, heart of Leo, is a degree to the moon’s lower right. As we look toward the moon and Regulus tonight, we are looking out the “rear window” of Spaceship Earth, opposite to the direction we are moving around the sun. Later this evening, Venus has its northernmost setting of this year.

May 23: It’s the first day Saturn rises before Venus sets, but only by 5 minutes. With mountains surrounding us, it is difficult to find a spot to see both planets simultaneously—but the “window” of opportunity opens 5 minutes wider each day.

May 25 at dusk: Spica in Virgo is within 7 degrees to the lower right of the waxing gibbous moon.

May 26 at dusk: Jupiter is within 9 degrees to the moon’s lower left.

Sunday, May 27, at dusk: The moon is in the southeast, with Jupiter 6 degrees to its lower right.

May 28: The nearly full moon rises some 43 minutes before sunset. Can you catch the sun and moon simultaneously? At dusk, note Jupiter 18 degrees to the moon’s upper right, and Antares 11 degrees to the moon’s lower right.

May 29: The moon, just past full, rises about 13 minutes after sunset. At dusk, Jupiter is 30 degrees to the upper right of the moon. Antares, heart of Scorpion, is 10 degrees to right of the moon.

May 30 at dusk: Venus is 10 or 11 degrees below the “Twins” tonight and tomorrow, forming a nearly isosceles triangle.

May 31 at dusk: Venus and Jupiter appear 120 degrees apart tonight. As we approach the dates of the oppositions of Saturn and Mars in late June and late July, respectively, those planets are beginning to appear in late evening: Saturn now rises within two hours after sunset, and Mars rises just two hours after Saturn.

The website of the Astronomical Society of the Desert at www.astrorx.org has a listing of our evening star parties at two locations. The primary, more accessible location is at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within 4 miles south of Highway 111 in Palm Desert). Our last sky viewing session for the season at that location is scheduled on Saturday, May 19, from 8 to 10 p.m.Sawmill Trailhead, our high-altitude site (elevation 4,000 feet), will have a star party starting at dusk on Saturday, May 12. (Star parties at that location will continue monthly.) Listings on the society’s website includes maps and directions for both locations. Star parties can be cancelled in poor observing weather. Also, check the link to “Impromptu Star Parties” on that website for star parties announced on short notice. There will be some in Palm Springs during May.

The Abrams Planetarium is making available online the May 2018 Sky Calendar with an evening sky map. It may be reprinted for free distribution. To download the calendar and map, visit www.abramsplanetarium.org/skycalendar.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky-watching opportunities for a variety of groups in the Coachella Valley. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

The two brightest “stars” in the April evenings are really planets. Venus continues to gain altitude in the west to west-northwest at dusk, as the time of its setting shifts from 1.6 hours after sunset on April 1, to 2.2 hours after on the 30th. Jupiter doesn’t appear on our evening mid-twilight chart until almost month’s end; it rises in east-southeast just more than three hours after sunset on the 1st, to just more than a half-hour after on the 30th.

Next in brilliance at dusk are blue-white Sirius in the southwest; golden orange Arcturus climbing in the east-northeast to east; and yellow Capella, high in the northwest.

In the morning, Jupiter, in the southwest at dawn, is easily the brightest morning “star.” Ranking next are Arcturus in west, and Vega passing just a few degrees north of overhead. Mars, just east of due south, is slightly fainter than these stars as April begins. But as Earth closes its distance to Mars—from 103 million miles on the 1st to 79 million miles on the 30th—the planet begins to outshine those stars. In early April, Mars is closely accompanied by Saturn; they appear closest, within 1.3 degrees, on April 2. By month’s end, Mars-Saturn are 14 degrees apart.

Other bright stars in the morning sky are Altair and Deneb, completing the Summer Triangle with Vega; Antares, between Jupiter and Saturn, but below the line joining these two giant planets; and Spica, sinking in the west-southwest, to the lower right of Jupiter and lower left of Arcturus. On April 13, Spica is at opposition as the Earth passes between that star and the sun. On April 13-14, look for Spica in the east-southeast at dusk, well up in south in middle of night, and low in the west-southwest at dawn. Mercury, brightening slowly from magnitude +1.0 to +0.4 during April 19-30, is very low in the east in dawn twilight. In this poor apparition, binoculars are recommended.

On the morning of April 2, Spaceship Earth is heading toward a direction in space within 4 degrees east (to the left) of the Mars-Saturn pair. As our planet follows its nearly circular orbit around the sun, we will overtake all three bright outer planets, and each will take its turn at opposition and all-night visibility: Jupiter on May 8, (Antares on May 31), Saturn on June 27, and Mars on July 26. Mars, the next planet outward from Earth, will brighten spectacularly in July, outshining even Jupiter.

For events at dawn, the suggested viewing time is generally one hour before sunrise. For events at dusk, look one hour after sunset, except when noted.

Easter Sunday, April 1, at dawn: Spica is 6 degrees south of the moon in the west-southwest. Jupiter is in the south-southwest to southwest, 29 degrees to the upper left of the moon. The Mars-Saturn pair is in the south-southeast, 1.4 degrees apart, about 46 degrees left of Jupiter.

April 2 at dawn: Mars passes within 1.3 degrees south of (below) Saturn; the pair is 47 degrees east (left) of Jupiter. Red supergiant star Antares, heart of the Scorpion, is 19 degrees to the lower left of Jupiter and 29 degrees to the lower right of Mars.

April 3 at dawn: Mars-Saturn are 1.4 degrees apart. Jupiter is within 4 degrees to the lower left of the moon in the southwest. Four hours after sunset: The moon is low in the east-southeast, within 9 degrees to the lower left of Jupiter.

April 4 at dawn: Jupiter is 11 degrees to the lower right of the moon; Antares is 11 degrees to the lower left of the moon.

April 5 at dawn: Antares is within 10 degrees to the lower right of the moon. Mars-Saturn are 2 degrees apart.

April 6 at dawn: Mars-Saturn are 2.4 degrees apart, 12-14 degrees east (to the left) of the moon. Four solar system bodies—in order from west to east, Jupiter, the moon, Saturn and Mars—span 49 degrees.

April 7 at dawn: A beautiful gathering of the moon and two planets fits within the field of view of binoculars: Saturn about 1 degree to the moon’s lower right, with Mars just more than 3 degrees to the moon’s lower left.

Sunday, April 8 at dawn: The moon, in the south-southeast, has just passed last quarter phase and appears slightly less than half-full. All three bright morning planets are now west of the moon—Mars and Saturn by 9 and 12 degrees, respectively, and Jupiter by 59 degrees.

April 9 at dawn: Mars-Saturn are 4 degrees apart, 20 to 24 degrees to the upper right of the fat crescent moon.

April 11 at dawn: Mars-Saturn are 5 degrees apart.

April 12 at dawn: The distance from the crescent moon, low in the east-southeast, to Jupiter, in the southwest, spans 108 degrees. Dusk: Venus appears 15 degrees directly below the Pleiades star cluster, aka the Seven Sisters.

April 13 at dawn: This the last easy chance to view the waning crescent moon, rising within 10 degrees south of east in twilight; Spica is at opposition in the west-southwest. Between them, find Jupiter in the southwest, and Saturn and Mars 6 degrees apart in the south to south-southeast. At dusk: Find Spica low in the east-southeast. When Spica passes due south in the middle of night, look 36 degrees below it and only 3-4 degrees up for the globular cluster Omega Centauri, some 17,000 light-years away. Seen through binoculars in very dark skies, it appears as a round, fourth-magnitude fuzzy ball about as large as the moon.

Sunday, April 15: The new moon, closely south of the sun at 6:57 p.m., is invisible today!

April 16, about 25-40 minutes after sunset: From a place with an unobstructed view, some 10 degrees north of west, try to see the thin crescent moon, very low—2 to 5 degrees above the horizon—within 13 degrees below and slightly left of Venus. The moon’s age is about 25 hours past new. As the sky darkens, look for the Pleiades cluster 10 degrees above Venus. Binoculars give best views of the moon and of Pleiades.

From places with unobstructed views toward the east-southeast and west-northwest, Jupiter now rises just 8 minutes before Venus sets, and it is briefly possible to observe both planets simultaneously above opposite horizons. By April 24, Jupiter will rise one hour before Venus sets, so it will become easier to do so. By April 30, Jupiter will rise 99 minutes before Venus sets. It remains possible to observe these two bright planets simultaneously at dusk until early October, when Venus sinks into twilight.

April 17 at dawn: Mars and Saturn are 8 degrees apart. At dusk: Venus appears within 6 degrees to the right of the crescent moon, with earthshine illuminating the moon’s dark side.

April 18 at dusk: Don’t miss this special, beautiful sight! Within an hour after sunset, the moon is framed by the V-shaped head of Taurus, the Bull, composed of bright Aldebaran (marking the Bull’s eye 67 light years away, within 2 degrees to the moon’s upper left), and the fainter remaining stars of the “V,” members of the more distant Hyades cluster. Watch the moon close in on Aldebaran as the evening progresses. By 10 p.m., the star appears just 1 degree to the upper left of the moon’s center.

April 19 at dusk: Pleiades is 7 degrees to the upper right of Venus, with Aldebaran 13 degrees to the lower right of the moon.

April 20 at dusk: Betelgeuse, shoulder of Orion, is 15 degrees to the lower left of the moon. Below Betelgeuse, look for Orion’s three-star belt, and still lower, Orion’s foot, Rigel. Look for these stars each evening within an hour after sunset in coming weeks, and watch for their annual departures below the western horizon.

April 21 at dawn: Mars and Saturn are 10 degrees apart. Dusk: Pleiades is 5 degrees to the upper right of Venus. Pollux is 9 degrees to the upper right of the moon, with Procyon 15 degrees to the moon’s lower left.

Sunday, April 22, predawn darkness hours: It’s the peak of the Lyrid meteor shower. In early afternoon, the moon passes first quarter, 90 degrees east of the sun, and appears half full. In the late evening, the moon passes 2 degrees south of the Beehive cluster. You’ll need binoculars or a telescope to see the cluster’s stars so close to the moon.

April 23 at dusk: Regulus is 10 degrees to the lower left of the moon. Venus is within 4 degrees south (lower left) of Pleiades.

April 24 at dawn: Three bright outer planets—from west to east, Jupiter, Saturn and Mars—span 60 degrees. Mercury is also visible, very low in the east. Dusk: Regulus, heart of Leo, the Lion, is 4 degrees to the moon’s upper right. Venus’ least distance from Pleiades occurs tonight, as the planet passes 3.5 degrees south of the cluster’s brightest member.

April 25 at dusk: Pleiades is 4 degrees to the right of Venus, with Aldebaran 10 degrees to Venus’ upper left.

April 26 at dusk: Venus is nearly on line, joining Pleiades and Aldebaran.

April 27 at dusk: Spica is 11 degrees to the lower right of the moon.

April 28 at dusk: Spica is 8 degrees to the right of moon and a little higher. Watch for Jupiter rising 21 degrees to the lower left of the moon.

Sunday, April 29 at dusk: Venus is equidistant from Pleiades and Aldebaran—7 degrees from each. The full moon is 19 degrees to the lower left of Spica and 8 degrees above Jupiter.

April 30 at dawn: Jupiter is 5 degrees to the left of the moon in the southwest to west-southwest. Mars-Saturn are 14 degrees apart in the south-southeast to south. At dusk, watch for moonrise 6 degrees to the lower left of Jupiter in the east-southeast.

The website of the Astronomical Society of the Desert  has a listing of our evening star parties at two locations. The primary, more accessible location is at the visitor center of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within four miles south of Highway 111 in Palm Desert). A sky viewing session is scheduled there on Saturday, April 21, from 8 to 10 p.m. Sawmill Trailhead, our high-altitude site (elevation 4,000 feet), will have a star party starting at dusk on Saturday, April 14. Listings of star parties on the website include maps and directions for both locations. Star parties can be cancelled in poor observing weather. Also, check link to “Impromptu Star Parties” on that website for star parties announced on short notice.

Robert Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for a variety of groups in the Coachella Valley. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

As was the case back in January, March 2018 has two full moons. The first one almost coincides with its rising at sunset on the March 1. The second full moon of the month, sometimes called a “Blue Moon,” occurs in morning twilight on the 31st, before its setting just after sunrise. The moon will not be unusually close this time, nor will there be an eclipse, so there won’t be much media hype about this year’s second “Blue Moon” on March 31.

In March 2018, the predawn sky continues to host the three bright outer planets, all fitting within a span of 44 to 46 degrees. Starting with the full moon on March 1, follow the waning moon each morning through the 15th, and watch it pass above bright Jupiter on March 7, then skip from right to left of Mars March 9 and 10, and from right to left of Saturn March 10 and 11.

In the early evening, Venus can be spotted as a bright point of light very low in the western twilight glow, its visibility improving as the time of its setting after the sun broadens from 57 minutes to 93 minutes. Mercury can be spotted in the same binocular field as Venus for first three weeks, but fades rapidly after mid-month. Catch the moon at dusk on March 18 as a thin crescent low in the west, to the lower left of Venus and Mercury. Then follow moon nightly until March 31, when it’s full, rising just south of east within a half-hour after sunset. After Venus, evening’s most prominent point of light is Sirius, the “Dog Star,” the in southern sky at dusk in March.

Our morning chart for March depicts daily positions of all three bright outer planets and the half-dozen stars of first magnitude or brighter visible all month about 40 minutes before sunrise, before they fade into twilight. Jupiter, of magnitude -2.2 to -2.4 in the south-southwest to southwest, is the brightest “star” at dawn. The brightest actual stars are golden Arcturus, high in the southwest to west, and blue-white Vega, very high in the east-northeast to northeast. Saturn, of magnitude +0.6 to +0.5 in the south-southeast, glows about 45 degrees east of Jupiter. Mars, brightening from magnitude +0.8 to +0.3 and starting to outshine Saturn, strangely seems to hover nearly stationary in the sky all month, just more than 30 degrees up in the south-southeast to south. But Mars is really shifting nearly 0.6 degrees per day east against the background of stars, which appear to be sliding westward behind the planet. Watch Mars narrow its distance west of Saturn from 15 degrees on March 4, to 10 degrees on March 14, 5 degrees on March 24, and 2 degrees on March 30. Against stars on March 29, Mars passes within 1.9 degrees north of (above) third-magnitude Lambda, or Kaus Borealis, the northern star of the bow of Sagittarius, the Archer.

Look about an hour before sunrise to catch these events:

March 1: Regulus is 4 degrees to the lower right of the full moon.

March 4 and 5: Spica is 10 degrees to the lower left, then 8 degrees to the lower right, of the waning gibbous moon.

March 7: Jupiter is 4 degrees to the lower right of the moon, now two-thirds full.

March 8: Antares, heart of Scorpius, is 9 degrees below the moon.

March 9: Mars is 6 degrees to the lower left of the last quarter (half full) moon. Also, Jupiter, two months before its opposition, is stationary against background stars 8 degrees east of third-magnitude Alpha in Libra, and begins to retrograde.

March 10: Mars is 7 degrees to the right of the fat crescent moon. Saturn is 6 degrees to the lower left of the moon.

March 11: Saturn is 6 degrees to the right of the moon.

March 15: This is the last chance for the thin old crescent moon, very low in the east-southeast in twilight.

March 31: Spica is 15 degrees to the upper left of the moon.

In the evening: Have you ever seen Mercury? Here’s your chance! Our solar system’s innermost (and smallest known) planet has its best evening appearance of this year in the first three weeks of March. It sets in a deeper stage of twilight than it will during either of its two other evening showings, in July and November. And in March, Mercury will be very easy to find, within the same binocular field as Venus. All you need is a clear sky very low in the west, and an unobstructed view, without nearby high mountains blocking your line of sight toward the planet duo. Choose your viewing site carefully!

On March 1, Mercury will shine at magnitude -1.3, only 1.7 degrees to the lower right of 10-times-brighter Venus, at magnitude -3.9. On March 2, they’re 1.3 degrees apart, and on March 3, Mercury passes within 1.1 degrees to the right of Venus, with the pair setting just within an hour after sunset. Night by night, Mercury creeps a little farther to the upper right of Venus, to 2 degrees by March 6, on to a maximum of 4.1 degrees of Venus on March 14.

On March 15, Mercury, still bright at magnitude -0.3, reaches greatest elongation, 18 degrees from the sun, and at the end of its apparent orbit as we observe it from Earth. Mercury is then rapidly approaching Earth and begins to curve around to the near side of its orbit, where telescopically, it presents an ever-thinner crescent, fading as the planet’s surface features, large and small, cast shadows. Faded to magnitude +0.3, Mercury reaches a secondary minimum distance of 3.8 degrees to the upper right of Venus on March 18, the same evening when the 37-hour-old crescent moon passes 4 degrees to the south (lower left) of brilliant Venus.

On March 20, spring begins at 9:15 a.m., as the sun passes directly over the equator. That evening, the two inner planets set together, Mercury faded to magnitude +0.9, appearing 4.1 degrees to the right of Venus. Thereafter, Mercury quickly drops into bright twilight and fades. On March 21, it has faded to magnitude +1.2 and appears 4.5 degrees to the lower right of Venus. On the 22nd, Mercury is 5.2 degrees to the lower right of Venus, and is a challenging magnitude +1.5.

Orion’s three-star belt, not shown because its stars are of just second magnitude, is prominent in the south to southwest at dusk. It is flanked by red Betelgeuse, his shoulder, and blue-white Rigel, his foot. Extend the belt eastward to Sirius, the brightest star. Extend the belt in the opposite direction, and bend north a bit to Aldebaran, eye of Taurus. Some 14 degrees farther, locate a compact cluster of stars, the Pleiades, or Seven Sisters, a beautiful sight for binoculars! Procyon, the lesser Dog Star, completes the Winter Triangle with Betelgeuse and Sirius. North of the Winter Triangle, Orion and Taurus lie Pollux and Castor, the twin stars of Gemini, just 4.5 degrees apart, and Capella, the Mother Goat Star. Regulus, heart of Leo, follows the whole shebang across the sky, as if chasing his dinner menu items.

The moon is near bright objects in evening sky:

March 1: Regulus is 13 degrees to the upper right of the full moon.

March 18: Venus and Mercury are 4.1 and 7.6 degrees, respectively, to the upper right of a young crescent moon low in the west.

March 22: Aldebaran is 2 degrees below the moon.

March 25: Pollux is 9 degrees north of the moon; Procyon is 14 degrees south of the moon.

March 27 and 28: Regulus is 6 degrees to the lower left, then 8 degrees to the upper right, of the moon.

March 31: Before the end of twilight, watch for the rising of Spica, within 8 degrees to the lower right of the moon, just past full.

On Friday, March 2, Dennis Mammana, author of six books on astronomy and the “Stargazer” nationally syndicated newspaper column, will present a lecture at the Portola Community Center, 45480 Portola Ave., in Palm Desert. Doors open at 6:30 p.m. for refreshments, and the talk begins at 7 p.m.

The website of the Astronomical Society of the Desert has a listing of our lectures, and of our evening star parties at two locations. The primary location is at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within 4 miles south of Highway 111, in Palm Desert). A sky viewing session is scheduled there on Saturday, March 10, from 6 to 9 p.m. Sawmill Trailhead, our high-altitude site (elevation 4,000 feet), will have a star party starting at dusk on Saturday, March 17. Star parties can be cancelled in poor observing weather. See also the link to “Impromptu Star Parties” on the website.

Also, check out the Sky’s the Limit Observatory and Nature Center in Twentynine Palms, at skysthelimit29.org.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for a variety of groups in the Coachella Valley. Robert D. Miller did graduate work in Planetarium Science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

In February 2018, the predawn sky hosts all three bright outer planets, spanning 44 degrees. After the total lunar eclipse at dawn on Jan. 31, follow the waning moon each morning in the first half of February, and watch it pass Jupiter on Feb. 7; Mars on Feb. 9; and Saturn on Feb. 11.

Evenings offer the challenge of spotting Venus low in the western twilight glow, getting easier as its setting time improves from 24 to 56 minutes after sunset. Follow the waxing moon evenings from Feb 16, as a thin crescent near Venus, until March 1, when it’s full. Until Venus emerges from bright twilight, the evening’s most prominent point of light is Sirius, the brilliant “Dog Star,” in the southeast at dusk in February.

Our morning twilight chart for February shows bright Jupiter nearly 40 degrees up in the southern sky. On Feb. 1, Mars is 12 degrees to Jupiter’s lower left, with Saturn another 31 degrees to the lower left of Mars. On Feb. 1, note the moon, two bright stars and the three planets lie in a long straight line across the sky, from the moon in west, to Saturn in southeast. In order that morning, they are: the moon, Regulus, Spica, Jupiter, Mars and Saturn. Note also the reddish star Antares, heart of the Scorpion, to the lower left of Mars on Feb. 1. Look about an hour before sunrise each morning through Feb. 13, and watch for these events:

Feb. 2: Regulus is 11 degrees to the lower right of the moon.

Feb. 5: Spica is 6 to 7 degrees to the lower left of the moon.

Feb. 7: Jupiter is 5 degrees to the lower left of the last-quarter moon—half full and 90 degrees, or a quarter-circle, west of the sun. Mars appears within 6 degrees of Antares for 10 mornings, Feb. 7-16. Compare them in color and brightness. At closest approach in late July 2018, Mars will outshine Jupiter!

Feb. 8: Jupiter is within 9 degrees to the right of the fat crescent moon. Mars is within 9 degrees to the moon’s lower left, while Antares is 5.5 degrees below Mars.

Feb. 9: Mars is 5 degrees to the lower right of the moon, with Antares 9 degrees to the lower right of the moon, and 5.3 degrees to the lower right of Mars. Saturn is within 24 degrees to the lower left of the moon. Jupiter is 20 degrees to the moon’s upper right.

Feb. 10: Visualize our dynamic solar system as you observe the planets in the morning sky. Today, Jupiter lies directly ahead of Spaceship Earth in our orbital motion around the sun. We’ll curve around the sun to pass between Jupiter and the sun in early May, and that planet will appear at opposition, 180 degrees from the sun. We’ll similarly overtake Saturn in late June, and Mars in late July, each taking its own turn at opposition.

Feb. 11: Saturn is within 2 degrees to the lower right of a striking lunar crescent, with earthshine illuminating the moon’s dark (non-sunlit) side. Mars and Antares, now 26 to 27 degrees to the moon’s upper right, appear closest together, just 5.1 degrees apart this morning and tomorrow. Mars, moving 0.6 degrees east daily against background stars, will appear midway between Jupiter and Saturn, 22 degrees from each, on Feb. 19.

Feb. 12: The waning crescent moon, only 10 percent full, is low in the east-southeast to southeast, 12 degrees to the lower left of Saturn.

Feb. 13: The last easy-to-see crescent moon, 5 percent full, is 24 degrees to the lower left of Saturn. The Mars-Antares pair is 5.2 degrees apart, within 19 degrees to the lower left of Jupiter.

Feb. 14: You have one last chance to catch the waning moon: Just 25 minutes before sunrise, if the sky is very clear, look 2 degrees up in the east-southeast for the hairline old crescent, 2 percent full and 31 hours before the invisible new moon, which occurs on Feb. 15 at 1:05 p.m.

February’s evening twilight sky chart plots Venus barely above the horizon 40 minutes after sunset, just south of west, in the last 10 days of month. Improve your chances to spot Venus and begin seeing it earlier in month by using binoculars and looking closer to the time of sunset. Find a spot where mountains won’t block your view! The brightest stars are Sirius in the southeast, and Capella, very high, northeast to north of overhead. They mark the southern and northern vertices of the huge Winter Hexagon, in clockwise order from Capella: Aldebaran, Rigel, Sirius, Procyon, the Twins (Pollux and Castor) and back to Capella. Orion’s shoulder, Betelgeuse, sits inside. Regulus, heart of Leo in the east, chases the Winter Hex across the sky.

Here are some of this month’s evening events:

Feb 16: Around 5:22 p.m., or 22 minutes after sunset, the sun is 5 degrees below the horizon, while the young crescent moon, only 1 percent illuminated, is 6 to 7 degrees up and 16 degrees south of due west. Very clear skies and an unobstructed horizon are essential for success within the next 10-minute window, and binoculars will greatly increase your chances. Venus appears as a point of light within 3.4 degrees to the lower right of the illuminated lower right limb of the moon. You’re likely to spot Venus first, since its light is concentrated within a tiny disk. If so, look to the upper left of Venus for the faint arc of the nearly 29-hour-old crescent.

Feb. 17: About 25 minutes after sunset, the sun is 6 degrees below the horizon (civil twilight), while the moon is 17 degrees up, 9 degrees south of due west. At 5 percent, the crescent should be easy to see in clear skies. Can you spot Venus 15 degrees to the moon’s lower right and just 3 degrees up? Venus is just beginning its evening apparition, lasting until early October.

Feb. 18: Regulus is at opposition as Earth passes between that star and the sun. Tonight, Regulus is visible all night.

Feb. 22: The moon, nearing first-quarter phase when it’s 90 degrees east of the sun and appearing half-full, is 9 degrees south of the Pleiades (Seven Sisters) star cluster this evening, and 9 degrees west of Aldebaran, eye of Taurus. By moonset tonight, the moon will appear 6 degrees to the lower right of Aldebaran.

Feb. 23: At dusk, the slightly gibbous moon is high in the south, with Aldebaran 5 degrees to its lower right. Note Betelgeuse 17 degrees to the moon’s lower left.

Feb. 24: The moon and Betelgeuse, 12 degrees to its lower right, lie near the center of the Winter Hexagon.

Feb. 25:Between tonight and tomorrow, the moon moves from inside to outside the Hexagon, jumping over the line joining Pollux, the brighter and more southerly Gemini Twin, and Procyon, the Little Dog Star.

Feb. 26: The moon is 10 degrees southeast of Pollux, in line with Pollux and its fainter Twin Castor.The Twins are 4.5 degrees apart, with Castor northwest of Pollux and farther from the moon.

Feb. 27: Find Regulus, the heart of Leo, 16 degrees to the moon’s lower left.

Feb. 28: As evening twilight deepens, use binoculars to spot Regulus only about 1 degree to the moon’s lower right. Check every half hour; shortly after 9 p.m., the moon will pass closely north of the star, with less than a moon’s width of clearance between them. From the Arctic, the moon will occult or cover the star. At dawn on March 1, the moon will have moved 4 degrees east (to the upper left) of the star.

On Friday, Feb. 2, Bruce M. Gottlieb, president of the Astronomical Society of the Desert, will be speaking on “The Total Solar Eclipse of August 21, 2017.” Gottlieb will explain why eclipses happen, and share photos from his trip to Casper, Wyo., to view the eclipse. On Friday, March 2, Dennis Mammana, author of six books on astronomy and the “Stargazer” syndicated newspaper column, will present a lecture on an astronomy topic to be determined. Both lectures will be held at the Portola Community Center, 45480 Portola Ave., in Palm Desert. Doors open at 6:30 p.m., and the talks begin at 7 p.m.

The website of the Astronomical Society of the Desert has a listing of our lectures and of our evening star parties at two locations. The primary, more-accessible location is at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within four miles south of Highway 111 in Palm Desert). A sky viewing session is scheduled there on Saturday, Feb. 10, from 6 to 9 p.m. Sawmill Trailhead, our high-altitude site (elevation 4,000 feet), will have a star party starting at dusk on Saturday, Feb. 17. Star parties can be cancelled in poor observing weather. Also find the link to “Impromptu Star Parties” on the website.

Finally, check out the Sky’s the Limit Observatory and Nature Center in Twentynine Palms, at skysthelimit29.org.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for a variety of groups in the Coachella Valley. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

Evenings during twilight in early December 2017 feature a half-dozen stars of first magnitude or brighter, including the Summer Triangle of Vega, Altair and Deneb well up in the west, getting lower as month progresses; Fomalhaut, mouth of the Southern Fish, in the south; and Capella, the Mother Goat star, ascending in the northeast, with red-orange Aldebaran, eye of Taurus, to its lower right.

Binoculars and an unobstructed view are needed to spot Saturn, with Mercury close to its lower left, very low in the southwestern twilight glow 2.8 to 2.3 degrees apart Dec. 1-3, some 40 minutes after sunset. But both sink lower each evening, with Mercury fading to the equal of Saturn by Dec. 3, and fading rapidly thereafter. Mercury passes inferior conjunction, nearly between Earth and the sun, on Dec. 12, and Saturn hides in conjunction on the far side of the sun on Dec. 21.

In evening twilight late in month—or later in the evening in early December—watch the eastern horizon for the rising of reddish Betelgeuse and blue-white Rigel. About midway between them, Orion’s vertical three-star belt confirms their identity as Hunter’s shoulder and foot.

Our morning chart (below) depicts the sky about 45 minutes before sunrise, but we advise you to begin viewing at least a half-hour earlier than that, to allow time to locate all the bright objects before they are drowned out in the brightening twilight. Steady Jupiter in the southeast is the most prominent object during the half-hour beginning 75 minutes before sunup. (Venus doesn’t rise until 45 minutes before sunrise on Dec. 1; 30 minutes before on Dec. 12; and only 15 minutes before sunrise on Dec. 23.) Binoculars are increasingly useful for spotting Venus before sunup on the last possible date before superior conjunction, beyond the sun on Jan. 9.

Next in prominence after Jupiter are twinkling blue-white Sirius in the southwest to west-southwest, until it sinks from view late in the month; golden Arcturus high in the east; blue-white Vega rising higher in the northeast; and Capella sinking in the northwest. Mercury, very low in the east-southeast to southeast, attains magnitude +1 by Dec. 20, and magnitude 0 by Dec. 24, and for the rest of month ranks second in brilliance, after only Jupiter, since Sirius has departed.

Other bright morning objects include the Winter Hexagon, which has Sirius and Capella marking its southern and northern vertices, and red Betelgeuse inside. But Rigel, Aldebaran, Sirius and Betelgeuse exit the morning sky in December, leaving only the upper arch of Procyon, Pollux (with Castor 4.5 degrees to its right, not shown) and Capella.

Regulus, heart of Leo, is high in the southwest to west-southwest following the Hex across the sky. I like to imagine Leo chasing his menu, which includes some beef (Aldebaran in Taurus), two dogs (Sirius and Procyon in Canis Major and Canis Minor), a mother goat (Capella in Auriga) and even some human fare (Rigel and Betelgeuse of Orion, the Hunter, becoming the Hunted; and Pollux and Castor, of Gemini, the Twins).

Following Regulus across the sky are Arcturus and Spica. The latter star marks the ear of grain in the hand of Virgo, the next zodiac constellation east of Leo. The zodiac constellations serve as hosts to the bright objects of the solar system, namely the sun, moon and planets.

On Dec. 1, dim red Mars appears just 3 degrees from Spica and 16 degrees to the upper right of Jupiter. Jupiter itself is 4 degrees west-northwest of the third-magnitude star Alpha in Libra on Dec. 1; within 1 degree of that star Dec. 18-26; and as close as 0.7 degrees from Alpha Lib on Dec. 21-23. On Dec. 31, Mars is 3 degrees to the upper right of Jupiter, and 20 degrees to the lower left of Spica. On the last morning of 2017, Alpha Lib lies nearly midway between the planets, 1.5 degrees from Mars and 1.7 degrees from Jupiter—a beautiful sight for binoculars! The star’s Arabic name, Zubenelgenubi, meaning “Southern Claw,” refers to its assignment to a larger early version of the Scorpion, the next zodiacal constellation east of Libra. The pairing of Jupiter with Alpha Lib on Dec. 22 is the first of a triple conjunction between them. Jupiter, retrograding, will pass closely north of the star on June 3, 2018, and then, after resuming direct (eastward) motion, will pass closely north of it a third time, on Aug. 15.

Mercury, pulling away from its inferior conjunction of Dec. 12, brightens rapidly in the morning sky and holds a steady 28 degrees to the lower left of Jupiter Dec. 21-27. Look 8 degrees to the upper left of Antares, heart of the Scorpion, Dec. 20-27. During Dec. 28-30, Mercury is 9 degrees to the left or lower left of Antares. On Dec. 31, Mercury is 31 degrees to the lower left of Jupiter and 10 degrees to the lower left of Antares. On New Year’s morning, Mercury reaches greatest elongation, 23 degrees from the sun. On the mornings of Jan. 6 and 7, Mars will appear only 0.3 degrees from Jupiter. Within a week later, on Jan. 13, Mercury will pass 0.8 degrees south of Saturn. Wouldn’t a good pair of binoculars to view these events make a great gift for a skywatcher?

December opens with a few brightly moonlit nights. On Saturday evening, Dec. 2, the moon rises 20 minutes before sunset and is nearly full. An hour after sunset, find the Pleiades 10 degrees to the moon’s upper left, and Aldebaran, whose name means “the Follower” (of the Pleiades), within 14 degrees below the Pleiades and 7 degrees to the moon’s lower left. The moon creeps closer to Aldebaran throughout that night. During morning twilight on Sunday, Dec. 3, use binoculars to spot Aldebaran very close to the moon’s upper left. A “supermoon,” the closest full moon of 2017, occurs at 7:47 a.m. that morning, just more than an hour after moonset in Palm Springs. The moon reaches its least distance from Earth just 17 hours later, at 12:46 a.m. on Dec. 4.

Moonrise early on Sunday evening, Dec. 3 (as seen from Palm Springs), occurs at 5:11 p.m. Although more than nine hours past full, the moon, rising 33 minutes after sunset, will be impressive. Note Aldebaran 8 degrees to the moon’s upper right.

After it’s full, moonrise occurs later each night: On Monday, Dec. 4 at 6:10 p.m.; on Dec. 5 at 7:13 p.m. (northernmost moonrise of the month); on Dec. 6 at 8:19 p.m.; on Dec. 7 at 9:25 p.m.; and on Dec. 8 at 10:30 p.m.

On Dec. 5, two weeks have elapsed since Nov. 21, when Earth passed between the sun and the Pleiades (Seven Sisters) star cluster. Starting on Dec. 5, the moon is well below the horizon at the end of evening twilight, nearly 1 1/2 hours after sunset, and the sky is then dark and moonless. Starting on the evening of Dec. 5, face east-northeast to east at dusk and watch the Pleiades emerge and ascend in the deepening twilight. The scene is well described in lines by Alfred Lord Tennyson.

After the full moon, you can follow its motion in the morning sky, averaging 13 degrees per day eastward through the constellations of the zodiac. Watch the waning gibbous moon pass 9 degrees south of Pollux on Dec. 6, and leapfrog over Regulus on Dec. 8 and 9. On Dec. 12, find the waning crescent moon 9 degrees above Spica. On Dec. 13, the moon is 4 degrees to the upper left of Mars and 9 degrees to the lower left of Spica.

The moon rises very late on the night of Dec. 13 (as a 13 percent crescent at 3:21 a.m. on Dec. 14), leaving the peak of the Geminid meteor shower, overnight on Dec. 13-14, excellent for viewing meteors. Best hours are from Wednesday at 9 p.m. until first light of dawn at 5:15 a.m. on Thursday, although a few long trails from meteors grazing Earth’s atmosphere might be seen anywhere in the sky as Castor, near the shower’s radiant, rises soon after 6 p.m.

On the morning of Dec. 14, perhaps after a few good hours of meteor-watching, look for the moon passing 4 degrees north of Jupiter. On Dec. 15, find the moon within 12 degrees to the lower left of Jupiter. On the 16th, the last easy old crescent moon will appear 23 degrees to the lower left of Jupiter. If you have a very good low horizon between east-southeast and southeast, use binoculars to find Antares rising 9 degrees to the lower right of the crescent moon in brightening morning twilight.

In case the sky is very clear just after 6 a.m. on the morning of Sunday, Dec. 17, we have a site selected in northwestern Palm Springs to attempt a sighting of a very old moon, just a little more than 16 hours before new. We’ll announce the details in the “Impromptu Star Parties” link mentioned below.

We’re still checking out sites in Desert Hot Springs and the eastern Coachella Valley to attempt a sighting of a very young moon shortly after 5 p.m. on Monday, Dec. 18. The moon’s age will be just more than 18.5 hours. As the date draws near, visit the same link for details. Twelve days later, on Saturday, Dec. 30, the daytime waxing gibbous moon rising at 2:53 p.m. is covering Aldebaran. Telescopes may show the star emerging along the moon’s bright edge at 3:51 p.m.

The website of the Astronomical Society of the Desert, at www.astrorx.org, has a listing of our evening star parties at two locations. The primary, more-accessible location is at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within four miles south of Highway 111 in Palm Desert). A session is scheduled there on Saturday, Dec. 23, from 5-8 p.m. Sawmill Trailhead, our high-altitude site (elevation 4,000 feet—wear warm clothes), will have a star party starting at dusk on Saturday, Dec. 9. The society’s website includes maps and directions for both locations. Star parties can be cancelled in poor observing weather. See the link to “Impromptu Star Parties” on that website.

On Friday, Jan. 5, I will present a summary of the coming year’s sky events. The summer and early autumn of 2018 will be outstanding for viewing planets in the evening sky, and there will be total lunar eclipses in January 2018 and January 2019. The talk will be held at the Portola Community Center, 45480 Portola Ave., in Palm Desert. Doors open at 6:30 p.m. for refreshments, and the talk begins at 7 p.m.

Also, check out the Sky’s the Limit Observatory and Nature Center in Twentynine Palms, at skysthelimit29.org.

Wishing you clear skies!

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for a variety of groups in the Coachella Valley. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

November 2017 features twilight planetary pairs—one in the morning, and one in the evening.

Venus and Jupiter will appear close together low in the east-southeast morning twilight glow for a few mornings around Nov. 13, about 40-45 minutes before sunrise. In last 10 days of the month, Saturn and Mercury will appear within the same binocular field low in the southwest evening twilight glow, 40-45 minutes after sunset.

Of the morning planets, dim, distant Mars rises in a dark sky all month, improving from 2.6 hours before sunup on Nov. 1, to 3.5 hours at month’s end. Mars glows at magnitude +1.8 to +1.7, about as faint as it ever gets. Brilliant Venus, of magnitude -3.9, rises in ever brighter twilight, 1.3 hours before sunup on the 1st, and about 45 minutes hour before sunup on the 30th. Watch for Venus’ rising 16 to 34 degrees to the lower left of Mars as November runs its course.

On Nov. 2, binoculars readily show the star Spica rising in the twilight glow 3.5 degrees to the lower right of Venus. The other morning planet, Jupiter, at magnitude -1.7, is lost in the sun’s glare well below Venus in first few days, but from Nov. 8-18, may be found in the same binocular field as Venus. The two bright planets appear closest on Monday, Nov. 13, with Jupiter just one-third of a degree to the upper right of Venus. This month, on Nov. 29, Jupiter will rise in a dark sky just more than two hours before sunrise. As Venus rises in twilight that morning, Jupiter will appear 17 degrees to the upper right of Venus and 17 degrees to the lower left of Mars, midway between them.

Bright stars in morning twilight feature the huge Winter Hexagon of bright stars moving into the west. Sirius, the Dog Star, is its brightest and southernmost member. Orion’s red Betelgeuse lies inside the Hex, and Leo’s Regulus, high in the south-southeast to south, trails behind it. Bright Arcturus in the east-northeast to east, and Spica in the east-southeast to southeast, round out the list of 10 stars of first magnitude or brighter visible in all of November’s dawns. An 11th star, Vega, rises in the northeast late in the month, far to the lower left of Arcturus.

Around Nov. 21, our Spaceship Earth is heading directly toward the star Regulus. Go outdoors in the morning, and visualize our planet’s motion around the sun, and the motions of faster-moving Venus, the next planet inside Earth’s orbit, and slower-moving Mars and Jupiter, the planets next outside our orbit. If we could look “down” from “above” the solar system, the planets would appear to revolve counterclockwise around the sun. All the morning planets are ahead of us. Venus is moving even farther ahead, and will pass on the far side of the sun in January 2018. We’re gaining on Jupiter and Mars, and will overtake them next year.

Bright stars in evening twilight in all of November include the Summer Triangle, with Vega, Altair and Deneb passing west of overhead; and Fomalhaut, mouth of the Southern Fish, low in the southeast to south-southeast. Quickly slipping out of view early in the month are Antares, in the southwest to the lower right of Saturn, and Arcturus, in the west-northwest. Rising into view are Capella in the northeast, and Aldebaran in the east-northeast.

Evening planets: Saturn (magnitude +0.5) on Nov. 1 sets in a dark sky 2.7 hours after sunset, and telescopes reveal its rings tipped as much as possible, 27 degrees from edgewise. But Saturn sets ever earlier, sinking close to brighter Mercury (magnitude -0.4 to -0.1) in the latter half of the month. Mercury appears to the lower right of Saturn, by 10 degrees on Nov 17, and 7 degrees on Nov. 20. On Nov. 23, Mercury reaches greatest elongation—22 degrees from the sun and 4.7 degrees below Saturn. Thereafter, Mercury appears to the lower left of Saturn, by 4 degrees on Nov. 24, and 3 degrees on Nov. 28. This is quite an unfavorable appearance for our solar system’s innermost planet, as it remains mired low in twilight.

The moon is full on Friday, Nov. 3, and rises north of east a few minutes after sunset. Two nights later, on Sunday, Nov. 5, the waning gibbous moon rises in the east-northeast within two hours after sunset. Using binoculars, look for the reddish-orange star Aldebaran, eye of Taurus the Bull, close to the moon’s upper right. That night, the moon will gradually creep eastward against the background stars, away from Aldebaran. By an hour before sunrise on Monday, Nov. 6, the moon and star will be in the western sky, with the moon 6 degrees above the star.

Follow the moon daily an hour before sunup. On Nov. 8 and 9, watch it leap over the line connecting the Twins (Pollux-Castor) to Procyon. On Nov. 11, it stops just short of Regulus, heart of Leo. That morning, binoculars will show Regulus just east of the fat crescent moon. As seen from Palm Springs through a telescope that day, the leading bright edge of the moon covers the star at 8:55 a.m., and the moon’s trailing dark edge, invisible in daylight, uncovers it at 10:01 a.m.

By Nov. 11, you’ll want to look low in the east-southeast 40 to 60 minutes before sunrise each morning for a week, to follow the progress of the Venus-Jupiter pair. That morning, Jupiter appears 1.9 degrees to the lower left of Venus. On Sunday, Nov. 12, Jupiter appears just 0.9 degrees directly below Venus. Their closest pairing occurs on Monday, Nov. 13, with Jupiter now only one-third of a degree to the right of Venus and slightly higher. Jupiter is getting higher each day, Venus lower.

On Tuesday, Nov. 14, Jupiter appears 1.3 degrees to Venus’ upper right. By that morning, you can find faint Mars 6-7 degrees below the moon. On Nov. 15, find the crescent moon within 7 degrees to the lower left of reddish Mars and within 7 degrees to the upper left of blue-white Spica, forming a beautiful triangle with them. Some 17-19 degrees to the moon’s lower left, find the Venus-Jupiter pair still within 2.3 degrees apart. On Thursday, Nov. 16, in possibly the prettiest scene, Jupiter and Venus are 3.3 degrees apart, within 6 degrees to the lower right and 9 degrees below the moon. On Friday, Nov. 17, the moon’s final morning, look about 40 minutes before sunrise to spot the very thin old crescent within 5 degrees to the lower left of Venus. Jupiter will be 4.4 degrees to Venus’ upper right. Since the new moon occurs the next day, Nov. 18, at 3:42 a.m., a sighting of the moon on the morning of Friday, Nov. 17 will be about 22 hours before new.

Start looking for the young moon in the early evening on Sunday, Nov. 19. About 40 minutes after sunset, find the thin crescent very low in the west-southwest, with Mercury about 8 degrees to its left and a little lower. Saturn will be 12 degrees to the moon’s upper left and 8 degrees to the upper left of Mercury. The moon’s age will be nearly 38 hours after new. On the following evening, Nov. 20, seeing the moon should be very easy, as it sets in a dark sky nearly two hours after sunset. You still need to look early in twilight to catch Mercury, 8 degrees below the moon. Saturn will be 2 degrees to the moon’s lower left.

On the night of Nov. 21, Earth passes between the sun and the Pleiades (Seven Sisters) star cluster. Within an hour after sunset that evening, face east-northeast—opposite to the sun’s direction below the west-southwest horizon—and watch the Pleiades emerge and ascend in the deepening twilight. The scene is well described in lines by Alfred Lord Tennyson.

To celebrate the occasion of the Venus-Jupiter pairing, members of the Astronomical Society of the Desert are offering sky watches on Monday, Nov. 13, and the next four mornings, as the crescent moon passes through the gathering of three planets and a star, and the Venus-Jupiter pair grows wider each day. The sessions will be held from 5:15 until 5:45 a.m., on the pedestrian bridge crossing over Tahquitz Creek, at Camino Real between North and South Riverside drives, three blocks north of Cahuilla Elementary School. The session is dependent on sky conditions. If the sky is clear, we’ll be there, with telescopes and binoculars.

The website of the Astronomical Society of the Desert has a listing of our evening star parties at two locations. The primary, more accessible location is at the Visitor Center (VC) of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within four miles south of Highway 111 in Palm Desert). Sessions are scheduled there on Saturdays, Nov. 25 and Dec. 23, from 5 to 8 p.m. Sawmill Trailhead (SMT), our high-altitude site (elevation 4,000 feet—wear warm clothes), will have star parties starting at dusk on Saturdays, Nov. 11 and Dec. 9.

This year’s Night Sky Festival at Joshua Tree National Park will be held Nov. 10-12. For details, visit www.nps.gov/jotr/planyourvisit/night-sky-festival.htm. Also, check out the Sky’s the Limit Observatory and Nature Center in Twentynine Palms, at skysthelimit29.org.

Wishing you clear skies!

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

Rise early on these dark mornings, and you will be rewarded by a close planet pair, lots of bright stars, a star popping out from behind the moon, a meteor shower from Halley’s Comet, and a dust cloud in our solar system.

Evenings give us Saturn with rings now open to the max, and the Milky Way.

Our morning twilight all-sky chart for October 2017 at CVIndependent.com shows the changes in positions of naked-eye planets and stars of first magnitude or brighter at mid-twilight, when the sun is 9 degrees below the eastern horizon, some 40 minutes before sunrise. A bonus in October, while we’re still on daylight saving time: You don’t need to get up extra early by the clock to enjoy dark morning skies!

As the month progresses, stars will appear to drift from east to west along the tracks shown, owing to the revolution of Earth around the sun. Venus, of magnitude -4, still dominates the predawn sky. The chart shows Venus getting a little lower in the east each morning, because this swift inner planet is moving farther ahead of Earth and heading toward the far side of the sun, where it will arrive in January 2018, before emerging into the western evening sky.

Mars on Oct. 1 is only 2.5 degrees below Venus. The red planet now glows dimly at magnitude +1.8, as faint as it ever gets. But it plies its orbit more slowly than Earth, so we’ll gain on it, and it will appear higher each morning, passing only 0.2 degrees from Venus on Oct. 5, and climbing 16 degrees to Venus’ upper right by month’s end. Eventually, in late July 2018, Mars will appear low in the southwest at dawn (and in the southeast at dusk). The planet will then be at its closest to Earth since 2003, and up nearly all night, shining at magnitude -2.8.

Annually in October, the huge Winter Hexagon—in clockwise order from its brightest member, Sirius, Procyon, Pollux and Castor, Capella, Aldebaran and Rigel, with Betelgeuse inside—is well placed high in the sky before dawn. The flashing blue-white Dog Star Sirius is its most prominent and southernmost member. Sirius is the brightest star in Earth’s night skies, but it is much less bright than Venus. Capella, north or northwest of overhead, is the Hexagon’s second-brightest and northernmost member. Orion’s three-star belt (not shown) points to the lower left toward Sirius, and to the upper right toward Aldebaran, eye of Taurus, the Bull. Earlier, in darker skies, continue 14 degrees beyond Aldebaran to the striking Pleiades star cluster, beautiful in binoculars!

Far below the Hexagon is the second-brightest star in the heavens, Canopus. It reaches its high point just 4 degrees above the horizon due south at 5:30 a.m. on Oct. 16, near the start of morning twilight. But Canopus may not appear very bright, because much of its luster is lost during the last few miles of its beam of starlight coming in at a low angle through our atmosphere. Pick a very clear morning, and a place where mountains don’t block your view. I have seen this star from Palm Springs, looking through Palm Canyon in the Santa Rosa Mountains to my south. This far southern star reaches its high point 4 minutes earlier each day, 21 minutes before Sirius does, and 36 degrees lower.

Late in October, begin looking for bright, golden Arcturus rising in the east-northeast, and in the last couple of mornings, using binoculars, try for Spica in the same field as Venus. On Nov. 2, Spica will appear just 3.5 degrees to the lower right of Venus.

Morning moon wanderings: If you observe daily one hour before sunrise, then you’ll first spot the moon on Oct. 5, full and low in the west. Climbing steeply upward through the zodiac constellations day by day, the moon will appear 3-4 degrees to the lower right of Aldebaranon Oct. 9. Look through binoculars, and you may see several stars of the Hyades cluster, marking the face of Taurus, the Bull. On the next morning, find the moon 11 degrees to the upper left of Aldebaran.

The moon appears 11 degrees from Betelgeuse, Orion’s shoulder, on Oct. 10 and 11. On Oct. 12, the last quarter moon—half full and 90 degrees, or one-quarter circle, away from the sun—appears 10 degrees from Pollux, the brighter of the Gemini Twins, and 14 degrees from Procyon, the Lesser Dog Star. Look for Castor, the fainter Twin (not shown on the map), just 4.5 degrees north of Pollux.

Go outside shortly after 3 a.m. on Sunday morning, Oct. 15. When the 19 percent crescent moon rises at about 2:44 a.m., the star Regulus, heart of Leo, the Lion, will be hidden behind it! As the moon rises higher, the star will remain hidden for another half hour, until at 3:13 a.m., telescopes will show the star suddenly emerging at the dimly Earth-lit upper edge of the moon, then only 5 degrees above the horizon, and 11 degrees north of due east. By 5:30 a.m., the moon’s dim edge will be more than two-moon-widths from the star!

On Tuesday, Oct. 17, face east an hour before sunup to find a 5 percent crescent moon, with Venus 5-6 degrees below, and Mars 2 degrees to the upper right. On the next, final morning, Oct. 18, find the 2 percent, old crescent moon, 30 hours before new, 6-7 degrees to the lower left of Venus. The new moon, invisible in conjunction with the sun, occurs on Oct. 19 at 12:12 p.m. The morning sky thus becomes moonless, ideal for viewing the Orionid meteor shower at its best, in the dark predawn hours of Oct. 20-22. Orionids are dust particles originating from Halley’s Comet and might light up anywhere in the sky. Confirm a suspect meteor’s identity by extending its path backward past the start of its light-streak to a common origin, called the radiant. The true Orionids will appear to race away from the radiant in Orion’s club, north of Betelgeuse.

Another phenomenon excellent from very dark locations this time of year is the Zodiacal Light, reflected from comet and asteroid dust in the inner solar system. The best dates in the remainder of 2017 are Oct. 1, 2, Oct. 18-Nov. 1, and Nov. 17-30, about 90 minutes before sunrise. Look for a huge diffuse cone of light, broad near its base with its main axis near the ecliptic (marked by Regulus, the Beehive Cluster, Mars and Spica, after that star begins rising before morning twilight in November). Anza Borrego Desert State Park and Borrego Springs are fine places to observe the Zodiacal Light before dawn and the Milky Way after nightfall. This year, Oct. 19-22 would be an especially good time to visit; check out nightfallstarparty.com.

Our all-sky evening twilight chart for October shows the Summer Triangle of Vega, Altair and Deneb overhead, with Arcturus sinking low in the west to west-northwest, and Saturn with Antares 14-16 degrees to its lower right, in the southwest. Lonely Fomalhaut is in the southeast, in a rather barren area of the sky. Note the seasonal westward motions of the stars. The slow-moving outermost easy naked-eye planet Saturn, taking nearly 30 years to make one trip around the zodiac, gets dragged along with the stars’ seasonal motions. This month, telescopes show Saturn’s rings 27 degrees from edge-on, the maximum possible.

Arcturus is 33 degrees above the midday sun on Oct. 29, and is up nearly three hours longer than the sun, so for several days in late October and early November, you can catch Arcturus at two separate times: low in the east-northeast at dawn, and low in the west-northwest at dusk.

The first moon of the new cycle occurs on Friday, Oct. 20. Begin looking for the 2 percent crescent 6 degrees up in the west-southwest at civil twilight, when the sun is 6 degrees down, some 25 minutes after sunset, or 6:31 p.m. in Palm Springs and the western Coachella Valley. Mid-twilight (when the sun is 9 degrees down) occurs at 6:46 p.m., with the moon only 3 degrees up. To catch the 30-31 hour crescent, you’ll need to go to a place such as Desert Hot Springs or the far eastern Coachella Valley, where high mountains won’t block your view.

Within an hour after sunset on Sunday, Oct. 22, can you spot Antares 9 degrees to the lower left of the 10 percent crescent moon? On Monday, Oct. 23, the moon is in the southwest and 17 percent full, with Antares 12 degrees to its lower right and Saturn 6 degrees to the left. On Oct. 24, Saturn is 7 degrees to the moon’s lower right. The crescent is then nearly one-quarter full, but we must wait until the afternoon and evening of Oct. 27 to catch the first quarter moon, half full and 90 degrees east of the sun.

The website of the Astronomical Society of the Desert has a listing of our star parties. The primary location is at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within four miles south of Highway 111 in Palm Desert). Sessions are scheduled there on Oct. 28 from 7 to 10 p.m., and on Nov. 25 and Dec. 23, from 5 to 8 p.m. Sawmill Trailhead, our high-altitude site (elevation 4,000 feet—wear warm clothes), will have star parties starting at dusk on Sat. Oct. 14, Nov. 11, and Dec. 9. Also, check out the Sky’s the Limit Observatory and Nature Center in Twentynine Palms, at skysthelimit29.org.

Wishing you clear skies!

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in Planetarium Science and later astronomy and computer science at Michigan State University, and remains active in research and public outreach in astronomy.

Published in Astronomy

Our morning twilight all-sky chart for September, viewable below, shows the changes in positions of the naked-eye planets and the stars of first-magnitude or brighter, less than an hour before sunrise.

Changes are caused by the motion of the Earth and the other planets in their orbits. Stars will appear to drift from east to west across the sky as weeks pass, thanks to the revolution of Earth around the sun. Venus now dominates the predawn sky, but is getting a little lower each morning, because it is heading toward the far side of the sun, where it will arrive in January 2018.

Annually in September and October, the huge Winter Hexagon—in clockwise order from its brightest member, Sirius, Procyon, Pollux and Castor, Capella, Aldebaran and Rigel, with Betelgeuse inside—is well-placed high in the sky before dawn. The flashing blue-white Dog Star Sirius is its most prominent and southernmost member. Sirius is the brightest star in Earth’s night skies, but it does not appear as bright as Venus.

Morning planet gatherings: Low in the eastern morning sky in early September, Mars, Mercury and Regulus emerge to the lower left of Venus. Regulus, at magnitude +1.4, is the faintest of the first-magnitude stars. Mars is now even fainter, at magnitude +1.8, as dim as it gets—but Earth will catch up to it and close the gap. In July 2018, Mars will gleam at magnitude -2.8, visible all night, in the southwest at dawn (and southeast at dusk), and will be closer to Earth and brighter than at any time since the very close approach of August 2003.

On Sept. 4, Mercury, at magnitude +1.7, is a close match in brightness to faint Mars; they rise nearly at the same time, with Mars 3 degrees to the left of Mercury, and Regulus below them. Binoculars will show them in twilight about 17 degrees to the lower left of Venus, with the contrasting colors of reddish Mars and blue-white Regulus. All rise earlier each morning and get easier to see, especially Mercury, which brightens sharply, to magnitude +1.0 by Sept. 6; magnitude 0 on Sept. 9 and 10; and magnitude -1.0 on Sept. 18. Watch for these close pairs, all less than one degree apart: Mercury-Regulus on Sept. 10; Mercury-Mars on Sept. 16; Venus-Regulus on Sept. 18 and 19; Venus-Mars on Oct. 5; and Venus-Jupiter on Nov. 13. Binoculars will give a wonderful view of all these gatherings.

On Tuesday, Sept. 12, Mercury reaches a favorable greatest elongation, 18 degrees from the sun and 11 degrees to the lower left of Venus. Earlier on the same morning, telescopes show the moon covering and uncovering the first-magnitude star Aldebaran, eye of Taurus, the Bull. From Palm Springs, the star’s disappearance at the moon’s leading bright edge occurs just before 4:39 a.m., with reappearance at the trailing dark edge just after 5:53 a.m. Still earlier that morning, the dark edge of the moon uncovers a close pair of stars in the Hyades star cluster, at 1:31 and 1:38 a.m.

A few days later, on the mornings of Sept. 17 and 18, a waning crescent moon will appear near the Venus-Regulus pair, with the Mercury-Mars pairing below.

Follow the moon in evening sky: Careful viewers might spot a thin, young crescent moon very low in the west to west-southwest early on Thursday evening, Sept. 21, about 30 minutes after sunset, to the right of Jupiter. Find a spot without mountains blocking the view, and hope for very clear skies. It’ll be much easier to spot the crescent on the next evening, to the upper left of Jupiter. A much fatter crescent moon will pass the other giant planet, Saturn, on Tuesday evening, Sept. 26, with the twinkling reddish star Antares to their lower right. On the next evening, Sept. 27, the moon will reach first-quarter phase, 90 degrees or a quarter-circle east of the sun, and will appear half full. On Oct. 5, the moon will be full and will rise shortly after sunset, a little north of east, almost opposite to the sun’s direction in the sky.

Jupiter and Saturn are the slowest of the bright naked-eye planets. Jupiter takes nearly 12 years to make one trip around the sun, and Saturn takes about 29.5 years. Jupiter will pass 3.4 degrees north of Spica, the spike of grain in Virgo’s hand, on Sept. 11, and will return for a triple encounter with that star in 2029. Saturn appeared near Antares, heart of the Scorpion, in 2016, and will return to that star’s vicinity in 2045. Watch Jupiter creep slowly past Spica for several evenings around Sept. 11. Binoculars will help you pick up Spica to lower left of Jupiter as both sink into the twilight glow.

When the moon makes it around to Jupiter and Saturn from September 20-26, the planets will appear lower in the sky than they were early in the month, as shown on our all-sky evening twilight chart for September. So, if you’d like to enjoy telescopic views of both Jupiter and Saturn during an evening session, do it soon! (See a list of Astronomical Society of the Desert star parties at astrorx.org.) On these charts, note also the seasonal westward motions of Arcturus and the Summer Triangle of Vega, Altair and Deneb. The slow-moving outer planets seem to get dragged along with the stars’ seasonal motions.

To help you plan evening or morning planet-viewing sessions during the coming school year, see Jeffrey Hunt’s two-page graphic summary of moon and planet setting and rising times relative to times of sunset and sunrise—exact for Palm Springs—below.

Wishing you clear skies!

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy. Dr. Jeffrey L. Hunt, a retired planetarium director now living in the Chicago area, has taught astronomy and sky watching to all ages. He studied astronomy education at Abrams Planetarium at Michigan State University. Jeff writes an astronomy blog at jeffreylhunt.wordpress.com and can be followed on Twitter at @jeff_hunt.

Published in Astronomy

The summer of 2017 marks the 54th anniversary of my first successful expedition to observe a total solar eclipse.

The date was July 20, 1963, when our carload of astronomy graduate students from the University of Michigan made the long drive from Ann Arbor to the path of totality in Quebec. Cumulus clouds parted—and we had a spectacular view.

When it came to astronomy, I was hooked.

I hope some of you have a chance to make the journey to the August eclipse’s path of totality. This event is part of the Saros series—same as the eclipse I saw in 1963. These eclipses are spaced at intervals of 18 years plus about 11 1/3 days, and after three Saros intervals—called an Exeligmos—a solar eclipse very much like the one in 1963 happens again, within a similar track through our region of the world, only farther south. Instead of Alaska through Canada and Maine as in ’63, the ringside seats on Monday, Aug. 21, will be in Oregon to South Carolina, making this eclipse an exclusively American event.

Even if you can’t go to Oregon or another spot within the path of totality that day, there are many ways to safely observe the partial solar eclipse here. In California, it starts between 9:01 a.m. (on the Pacific Coast near Point Arena) and 9:11 a.m., when the noon’s penumbral (partial) shadow reaches the far southeast corner of the state, on the Arizona border. The moon’s penumbra begins to withdraw from California just after 11:34 a.m., when the eclipse ends on the Pacific Coast near Capetown. The moon’s outer shadow completely leaves the state just south of the Parker Dam on the Colorado River just after 11:55 a.m.

From most locations in California, the first contact of the moon with the sun’s disk occurs near the top of the solar disk (near “12 o’clock” on the disk, if it is imagined as a clock face). At greatest eclipse, the moon covers the upper left portion of the solar disk, centered near the equivalent of 10 o’clock, leaving a brilliant solar crescent uncovered near 4 o’clock. Last contact of the moon’s disk with the sun will occur at the lower left edge of the disk, near the 8 o’clock position. Of course, you must use proper eye protection to observe these events directly; see the web resources below. If you don’t have a solar filter, you can use projection methods.

Follow the moon before the solar eclipse: On Aug. 7, two weeks before the solar eclipse, there will be a full moon, with a partial lunar eclipse—but that event isn’t visible from our part of the world. (It occurs during our daytime, when the full moon, opposite the sun, is below our horizon.) Instead, watch a nearly full moon rise shortly before sunset of Aug. 6, and just a few minutes after sunset on Aug. 7. For the next several evenings, you can watch the moon rising later each night—or, you can shift your moon viewing time to mornings, either in predawn darkness or in the daytime after sunrise. Observe in the predawn darkness hours on Saturday, Aug. 12, and you’ll catch the Perseid meteor shower nearing its peak. Unfortunately, in 2017 the waning gibbous moon, still over three-quarters full that morning, will brighten the sky and reduce the number of meteors seen.

By the morning of Aug. 15, the moon will be just past last quarter phase, when it’s half full and 90 degrees west of the sun, but by then, the meteor shower activity will be well below peak. On the next morning, Aug. 16, look for bright Aldebaran, eye of Taurus, the Bull, just to the upper right of the crescent moon. Observe beautiful pairings of Venus with the waning crescent moon on Aug. 19 and 20.

As for Perseid meteors in evening: After the full moon of Aug. 7, the moon rises later each night, and by Aug. 11, it rises at 10:14 p.m., more than an hour after the end of evening twilight, at 9:08 p.m. In places far from the bright lights of human settlement—such as in Joshua Tree National Park or Borrego Springs—the sky will be very dark before moonrise, allowing spectacular views of the summer Milky Way and of Perseid meteors. Even before 9 p.m., the sky will be dark enough to observe some meteors. They might be seen anywhere in the sky, and the shower’s “radiant,” or the direction from which the meteors approach Earth, can be found by extending their trails backward to a common origin. Around 9 p.m., the radiant lies just a few degrees above the horizon in the north-northeast. When the radiant is low, the meteoroid particles enter Earth’s atmosphere at a very shallow angle, and very long trails of “Earth-grazing” meteors will be seen. As the night progresses, the radiant in the upper part of the constellation Perseus rises to more than 60 degrees above the horizon by the start of morning twilight, shortly after 4:30 a.m., and our part of the Earth will be presented more broadside to the incoming meteor stream. The meteor count would increase dramatically—were it not for the bright moon after it rises into view.

Good news for 2018: The Perseid peak will occur within two days after new moon, on the night of Aug. 10-11, so it will be a wonderful year for the shower!

Seasonal motions of stars: Venus now dominates the predawn sky, but is getting a little lower each morning, because it is heading toward the far side of the sun, where it will arrive in January 2018.

Annually by the beginning of August, there are several bright stars in the eastern morning sky. During the second week, Procyon and the Dog Star Sirius, the brightest star (not as bright as Venus) rise into view. Beginning then, if you catch Sirius rising in the east-southeast before Altair sets just north of west, you’ll see both the Summer and Winter Triangles—Vega, Altair and Deneb in the west to northwest, and Betelgeuse, Procyon and Sirius in the east to southeast—simultaneously, provided mountains don’t block Altair or Sirius from your view.

Follow the moon in the evening sky after the solar eclipse: Careful viewers might spot the young crescent moon early on Tuesday evening, Aug. 22, just 2 or 3 degrees above the horizon about 25 minutes after sunset, where no surroundings obstruct the view. It’ll be much easier to spot the crescent starting on Aug. 23. Through Aug. 31, notice the moon passing by two planets: Jupiter (with Spica nearby) on Aug. 24 and 25, and Saturn (with twinkling reddish Antares to its west) on Aug. 29 and 30.

To help you plan evening or morning planet viewing during the coming year (August 2017 to August 2018), refer to Jeffrey Hunt’s two-page graphic summary of the moon and planet setting and rising times relative to times of sunset and sunrise, exact for Palm Springs.

To help you plan evening or morning planet viewing during the coming year (August 2017 to August 2018), refer to Jeffrey Hunt’s two-page graphic summary of the moon and planet setting and rising times relative to times of sunset and sunrise, exact for Palm Springs, under the August AM sky chart below.

Wishing you clear skies!

Solar Eclipse information and Resources

http://www.skyandtelescope.com/total-solar-eclipse-august-2017/

http://www.skyandtelescope.com/observing/stargazers-corner/solar-eclipse-lab-sunny-day/

http://www.eclipsewise.com/solar/SEnews/TSE2017/TSE2017.html

https://eclipse.aas.org/

https://eclipse2017.nasa.gov/

https://www.astrosociety.org/education/2017-solar-eclipse-information-resources/

http://static.nsta.org/extras/solarscience/SolarScienceInsert.pdf

http://eclipsophile.com/total-solar-eclipses/total-solar-eclipse-2017-august-21/

http://aa.usno.navy.mil/data/docs/Eclipse2017.php

http://www.astronomy.com/great-american-eclipse-2017

https://www.greatamericaneclipse.com/

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy. Dr. Jeffrey L. Hunt, a retired planetarium director now living in the Chicago area, has taught astronomy and sky watching to all ages.  He studied astronomy education at Abrams Planetarium at Michigan State University. Jeff writes an astronomy blog at jeffreylhunt.wordpress.com and can be followed on Twitter at @jeff_hunt.

Published in Astronomy

July finds bright Jupiter in the south-southwestern sky at dusk, and Saturn in the southeast, closing to 65 degrees apart by month’s end. Before dawn, Venus gleams in the east, against the attractive background of Taurus the Bull, with its two prominent star clusters and bright reddish star.

On some dates, the moon forms attractive pairings with four of the five naked-eye planets, and four of the five bright zodiacal stars.

In July’s evening twilight, bright Jupiter attracts attention in the southwest, with bluish Spica nearby to its left, and golden Arcturus high above them. Yellowish Saturn glows steadily in the southeast to south-southeast, in contrast to the vigorously twinkling reddish star Antares, heart of the Scorpion, to its right. The star reaches south in mid-twilight near month’s end. The Summer Triangle, topped by its brightest star, blue-white Vega, ascends in the eastern sky. The Triangle’s other members are Altair, its southern point, and Deneb, trailing Vega.

Mercury has a several-weeks-long but very low apparition in the west-northwest to west. It loses nearly three-quarters of its brightness during July, fading from magnitude -1.0 to +0.4, and passes close by fainter, departing Regulus (+1.4) on July 25.

In July’s morning twilight, Venus continues climbing higher until late in the month, despite its having reached its greatest angular distance from the sun, 46 degrees, in early June. That’s because in July, the sun-to-Venus line inclines at an ever-steeper angle to our morning twilight horizon. Before dawn brightens much, watch Venus, shifting a little more than one degree daily against background stars, pass 6 degrees south of the Pleiades star cluster on July 5, and within 3.5 degrees north of Aldebaran on July 14. If you observe each morning at the same time interval, Venus will appear almost stationary during July, while the starry background rises toward the upper right, behind Venus. Note Capella far to the north (left or upper left) of Venus. Before month’s end, Orion’s brightest stars, Betelgeuse and Rigel, will appear in the east (with his striking three-star belt, not plotted, midway between the two), and Gemini’s Pollux, with Castor 4.5 degrees above it, will emerge in the east-northeast. Before mid-August, the Dog stars, Procyon and Sirius, will follow Orion into the eastern sky, completing the Winter Triangle with Orion’s shoulder, Betelgeuse.

On July mornings, the Summer Triangle of Vega, Altair and Deneb is still well up in west, and Fomalhaut crosses south toward southwest.

The moon and planets in July:On the evening of July 1, the gibbous moon appears several degrees north of Spica, with bright Jupiter just to their right; on July 5, the moon passes even more widely north of Antares. On the evening of July 6, the moon passes a few degrees north of Saturn. The moon is full two nights later, on Saturday, July 8. By that date, Mercury can be glimpsed very low in the west-northwestern evening twilight. Look to the lower right of Regulus,by 30 degrees on July 5, 15 degrees on July 14, 10 degrees on July 17, and shrinking to 5 degrees by July 21. We’ll return for another look at Mercury a few days later, after the moon has returned to the western early evening sky.

On July 8, we can catch the full moon rising in the east-southeast shortly before sunset; on the next evening, moonrise occurs within half an hour after sunset. Thereafter, the waning gibbous moon rises a little later and farther north each night. By July 14, the moon rises just before midnight, nearly due east. Instead of staying up late to wait for moonrise, get outdoors before sunrise, and follow the waning moon from July 9 through July 21 or 22. Venus, against a pretty background of the stars of Taurus, provides another reason to arise early, before the sky brightens much. Watch Venus go 6 degrees south of the Pleiades star cluster on July 5; just 3.5 degrees north of reddish-orange Aldebaran on July 14; a wide 7 degrees south of Elnath (Beta Tauri, tip of the Bull’s northern horn) on July 25; and very close to third-magnitude Zeta Tauri, the southern horn, on July 27. (Use binoculars to see the faint star near brilliant Venus on the 27th.) The waning crescent moon adds special beauty to the scene on three mornings: On July 19, find the moon to the upper right of Venus, Aldebaran and the Hyades star cluster. On July 20, the crescent moon will be just a few degrees to the south (lower right) of Venus. An hour before sunrise on July 21, the moon will be low in the east-northeast, well to the lower left of Venus, while Orion’s shoulder, Betelgeuse, will be rising widely to the lower right of the moon.

The moon rises at about the same time as Venus on July 20. Two days later, on July 22, binoculars may be required to spot the very old crescent.Look for the hairline 1 percent moon only 2 degrees up, one-half hour before sunrise, just 21-22 hours before new.

That new moon occurs on July 23, at 2:46 a.m.—one lunar month before the Aug. 21 solar eclipse! (See the May column at CVIndependent.com for a list of resources regarding that very special event.) The first view of this month’s young crescent moon is expected on the evening of July 24, within a half-hour after sunset. The 4 percent illuminated moon will then be 8 degrees up, 10 degrees north of west, at an age of 41-42 hours after new. As the sky darkens a bit, but before the moon gets too low, look a few degrees to the upper left of the moon for bright (magnitude +0.1) Mercury, with the fainter star Regulus (+1.4) just to the planet’s upper left. By the next evening, July 25, the crescent moon will have skipped to the upper left of the Mercury-Regulus pair, then at their closest, within a degree. Brighter Mercury will appear to the south (lower left) of Regulus. The evening of July 26 finds the moon far to the upper left of the now-widening pair.

On the evening of July 28, bright Jupiter is closely to the lower right of the fat crescent moon; note Spica several degrees to the left of Jupiter. On the next evening, July 29, the fat crescent moon, half a day short of first quarter, appears to the upper left of Jupiter and Spica, while Mercury reaches greatest elongation, very low, just north of west, and 27 degrees from the sun (which is below the horizon while you can see Mercury).

Check the website of the Astronomical Society of the Desert at www.astrorx.org for a listing of and directions to our star parties at Sawmill Trailhead, our high-altitude site (elevation 4,000 feet—wear warm clothes), starting at dusk on Saturday, July 22, Aug. 19, Sept. 23 and Oct. 14. Also, check out the Sky’s the Limit Observatory and Nature Center in Twentynine Palms, at skysthelimit29.org.

Robert C. Victor, formerly a staff astronomer at Abrams Planetarium at Michigan State University, is now retired and enjoys providing sky watching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in planetarium science, astronomy and computer science at Michigan State University, and remains active in research and public outreach in astronomy.

Published in Astronomy

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