CVIndependent

Tue10172017

Last updateWed, 27 Sep 2017 1pm

Robert Victor

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.

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.

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.

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.

Mid-June finds bright Jupiter high in the south-southwest at dusk, and Saturn low in the southeast, some 70 degrees apart. At dawn, Venus gleams in the east, while Saturn is low in the southwest. The moon forms attractive pairings with various planets and stars here and there throughout the month.

In our June evening twilight sky, bright Jupiter stands high in the south to southwest at dusk, with Spica nearby, to its lower left. As Jupiter ends retrograde motion against background stars in early June, it reaches a maximum distance of just more than 11 degrees west-northwest of Spica. Keep watch this summer, until Jupiter passes just 3 degrees north of Spica on Sept. 11. By then, they’ll be low in the west-southwest at dusk. After that, the next time Jupiter passes Spica will be during their triple conjunction in 2028-2029.

Also in June, we find Saturn rising in the southeast, to the lower left of Antares. Saturn is at opposition to the sun on the night of June 14-15 and is visible all night. In 2017, Saturn’s rings are tipped 27 degrees from edge-on, the greatest angle possible, with their northern face in view.

This year, these inspiring showpiece planetsJupiter with its cloud belts and four bright satellites discovered by Galileo, and Saturn with its spectacular rings and bright moon Titan in a 16-day orbit—are conveniently visible at dusk from mid-June through mid-September. Capture telescopic views of both planets in a single session! In coming years, as their opposition dates shift later, the window of dates to see both planets in the early evening starts about 12 days later each year, while the end of the window shifts about one month later annually. By 2020, both giant planets will be seen together in early evening skies from mid-July through December. The autumn of 2020 will be a fascinating time to watch these planets gradually close the gap between them—until they’re just 0.1 degree apart on Dec. 21, their closest pairing since 1623, during Galileo’s time. So, mark Dec. 21, 2020 on your calendar!

In June, you’ll need binoculars—and no mountains in the way—for final glimpses of faint Mars sinking into the west-northwest evening twilight glow. Look for it to the lower right of the “Twin” stars of Gemini, Pollux and Castor. In the eastern sky, watch for Altair rising to the lower right of Vega and Deneb, completing the Summer Triangle, while Arcturus climbs to its high point south of overhead. Summer begins on June 20 at 9:24 p.m., when the sun is directly overhead at the Tropic of Cancer. Earlier that day, the Coachella Valley observes the year’s highest sun passing, about 10 degrees south of overhead, at 12:48 p.m.

The appropriately named Summer Triangle is up all night from late June through early August. Whenever the Summer Triangle is high in a dark sky, the Milky Way will be in fine view, with one of its brightest star clouds inside the triangle, along the axis of the Northern Cross, or neck of Cygnus, the Swan. Binoculars will readily resolve that misty patch of light into multitudes of stars.

In June’s morning twilight, Venus is still brilliant in the east. Telescopes show it half-full early in the month, when it’s near greatest elongation, 46 degrees from the sun. Using binoculars, look to Venus’ lower left, low in the east-northeast, early in the month to catch departing Mercury, and later to catch emerging Aldebaran. Capella is the bright star ascending in the northeast. The Summer Triangle of Vega, Altair, and Deneb passes west of overhead. Fomalhaut is low in the southeast to south. Two bright stars depart the predawn sky in early June: Arcturus in the west-northwest, and Antares in the southwest. Saturn sinks to the horizon by month’s end, but you can catch it higher by looking earlier, before dawn twilight gets underway.

The moon and planets in June: On the evening of June 3, the waxing gibbous moon passes closely north of Jupiter, and on the following evening, more widely north of Spica. The moon passes the apogee of its orbit on the afternoon of June 8. That evening, it appears widely north of Antares, and on the next morning, the most distant full moon of 2017 appears several degrees to the lower right of Saturn, in the southwest. On the evening of June 9 through dawn on June 10, the moon, just past full, remains in close company with Saturn all night. Saturn is itself at opposition five nights later, on the night of June 14-15. By then, the moon rises just before midnight, so shift your viewing time to predawn to follow the rest of the moon’s cycle.

The last quarter occurs on June 17. On June 20, the waning crescent moon is a few degrees to the upper right of Venus. The next morning, June 21, the moon appears several degrees to the lower left of Venus, and to the lower right of the Pleiades star cluster. On June 22, the moon’s final morning, look for the 4 percent crescent rising in the east-northeast just more than an hour before sunrise. Can you spot Aldebaran, eye of Taurus, closely to the lower left of the moon? Less than 39 hours remain until the new moon, at 7:31 p.m. on June 23.

This graph of planets’ rising times below shows the moon rising closer to the time of sunrise each successive morning June 17-22, and just before Venus rises on June 20. Venus itself rises ever farther ahead of the sun until late July.

On June 24, the moon returns to the evening sky. Using binoculars, try for the 25-hour crescent a half-hour after sunset, when it’s 2 percent full and barely above the west-northwest horizon. Binoculars help! A sighting of this crescent ends the month of Ramadan and begins the next, Shawwal, in the Islamic calendar. On the next evening, June 25, spotting the moon will be much easier, when it’s 6 percent full and well to the left of Pollux and Castor. On the evening of June 27, there will be a close pairing of the moon and Regulus. The moon occults the star in the early afternoon from Hawaii, and in the early evening from Ecuador and Peru. From California, the crescent slips south of the star in late afternoon, and appears to the left of the star at dusk. By sunset on June 30, the moon has just passed first quarter phase and appears half full. That evening, bright Jupiter appears a few degrees southeast of the moon, and Spica several degrees southeast of Jupiter. It’s an ideal evening for telescopic views of the moon and Jupiter, and of the third-magnitude star very close to the moon! At 100-power, the star splits into a tight, matching pair of stars, with a period of revolution of 169 years. The pair will change noticeably during a lifetime, as it slowly widens and revolves away from its present north-south orientation.

This graph of planets’ setting times below shows the moon setting successively later each evening June 24-29: Just before twilight ends on June 25; about the same time Regulus sets on June 27; and more than four hours after sunset, just before Jupiter and Spica set, on June 29. Regulus will set in evening twilight by late in July, while Jupiter and Spica won’t sink into twilight until sometime in September.

Check the website of the Astronomical Society of the Desert at www.astrorx.org for a listing of our star parties at Sawmill Trailhead, our high altitude site (at 4,000 feet elevation—wear warm clothes), starting at dusk on Saturday, June 24, July 22, Aug. 19, Sept. 23, and Oct. 14.  Monthly star parties at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument will resume Oct. 28. The society’s website includes maps and directions.

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

Finally, remember the total solar eclipse coming to some parts of the country—but, alas, not here—on Monday, Aug. 21. See last month’s column for a list of Internet resources.

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 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, did the planet charts below. He has taught astronomy and sky watching to all ages. He studied astronomy education at Abrams Planetarium at Michigan State University and writes an astronomy blog at jeffreylhunt.wordpress.com.

Jupiter is now the most prominent “star” in the evening sky, and Venus, even brighter and near peak brilliance, rules predawn. By May’s end, Saturn rises at a convenient evening hour, allowing both giant planets to be viewed well in the early evening. The moon always appears as a crescent in its monthly encounters with Venus, but is full whenever it appears near Jupiter or Saturn in the eastern evening sky opposite the sun.

The young crescent moon at dusk on May 26 marks the beginning of Ramadan, and appears to the lower left of faint, departing Mars.

May evenings: A huge conclave of seven stars of first magnitude or brighter in the western sky begins its annual departure in early May. The collection consists of the six stars of the Winter Hexagon, with Betelgeuse inside. The entire Hex is still visible at the start of May, but sky watchers must look sharply for Rigel, about to set in bright twilight a little south of due west. On each successive evening, the stars’ setting times occur nearly 4 minutes earlier, ever closer to the time of sunset. During May, in order of disappearance, Rigel, Aldebaran, Sirius and Betelgeuse sink into the bright western twilight glow, as shown on our evening twilight chart for May. By Memorial Day, all that remains of the Hexagon is its upper edge, forming aMemorial Arch: Procyon low in the west, Pollux (and slightly fainter Castor, not plotted, 4.5 degrees to its right) atop the arch, and Capella, low in the northwest.

Venus left our evening sky in late March, leaving Jupiter to reign as the brightest “star” in the evening sky. Our evening twilight chart shows Jupiter ascending from the southeast toward the south during May. Last month, our planet Earth passed between the sun and Jupiter, and that planet appeared 180 degrees away from the sun in our sky on April 7, at opposition and visible all night, from dusk until dawn. Go outside on the evening of May 20, and visualize Earth’s motion of 18.6 miles per second around the sun and directly away from the star Regulus, while the Pleiades star cluster is hidden beyond the sun. Ten days later, in a grand annual syzygy on May 30, three stars and our planet lie in a nearly straight line in space, in the order of Aldebaran-sun-Earth-Antares. Aldebaran, eye of Taurus, is then invisible on the far side of the sun, while Antares, heart of the Scorpion, is at opposition to the sun and visible nearly all night. On our twilight chart, Antares is shown rising into view in the southeast late in May.

Other prominent stars on May evenings include bright golden Arcturus, high in the east to south; Spica, near Jupiter; Regulus, just south of a line connecting Jupiter to Pollux; and bright blue-white Vega, rising in the northeast, with Deneb following to its lower left.

The Abrams Planetarium Sky Calendar is available at www.abramsplanetarium.org/skycalendar. The May issue may be reprinted and distributed at no charge. The calendar includes illustrations of the moon passing by planets and bright stars, and the sky map depicts more stars and constellations than our twilight charts show.

In May’s morning twilight, we find brilliant Venus low in the east. Telescopes reveal Venus still in crescent phase in May, filling out to being half-lit by early June, but shrinking in size as the planet speeds away from Earth. Use binoculars to spot Mercury to the lower left of Venus starting in the second week. Follow Arcturus, sinking in the west to west-northwest; the Summer Triangle, passing overhead; and Saturn, with twinkling Antares to its lower right, sinking in the southwest. Fomalhaut is rising in the southeast.

The moon near planets and stars in May: Check illustrations on the May Sky Calendar to remind yourself to catch the moon near Jupiter and Spica on the evening of May 7. After the moon passes full on May 10, switch your viewing time to before dawn to see the moon pass widely north of Antares on May 12, and skip from west of Saturn to east of it on the next two mornings. The moon is near last-quarter phase (half full) on the mornings of May 18 and 19. Glance up to see the moon in the daytime before the morning start of your workday, and note how the side toward the sun is illuminated. If you hold a ball up at arm’s length to appear near the moon, you’ll notice the ball is illuminated in the same way.

In a spectacular conjunction before dawn on Monday, May 22, the waning crescent moon passes closely south of Venus. Seize the occasion to spot Venus in the daytime. Before dawn on May 23, the moon is to the lower left of Venus and to the upper right of Mercury. On May 24, use binoculars about 30 minutes before sunrise to try to see the rising of the old moon, just 3 percent full, some 8 degrees to the lower left of Mercury, and within 32 hours before new. It’ll be very low in bright twilight; you’ll need perfect skies and a low horizon to see it.

New moon occurs on May 25 at 12:44 p.m., only five hours after perigee, when the moon is closest to Earth. As a result, the moon ascends quickly from one evening to the next at the same stage of twilight. On May 26, 30 minutes after sunset, the first crescent moon, marking the start of the fasting month of Ramadan, should be easily seen if skies are clear. It will appear 3 percent full and about 7 degrees up in the west-northwest for sky watchers in the Coachella Valley. (You’ll need to go to a place where our high mountains won’t block the view.) As twilight deepens, binoculars may show faint Mars about 6 degrees to the moon’s upper right. In the rest of May, watch the waxing moon pass widely south of the Gemini twins Pollux and Castor on May 28, and leapfrog past Regulus on May 30 to 31. On the latter night, the moon is approaching first-quarter phase and is nearly half full.

The Astronomical Society of the Desert will host the last of the season’s monthly public star parties at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument, on Saturday, May 20, from 8 to 10 p.m. The Visitor Center is on Highway 74, within four miles south of Highway 111 in Palm Desert. After May 20, the next star party at the same location will be on Oct. 28. Check www.astrorx.org for listings. Star parties at the Sawmill Trailhead, our high-altitude site (4,000 feet—wear warm clothes), start at dusk on Saturday. June 24, July 22, Aug. 19, Sept. 23, and Oct. 14. Follow links to maps and directions.

Also, check the link to our “Impromptu Star Parties,” which could be announced on short notice at any time. Sessions might be scheduled at dusk or dawn to view planets—Jupiter with its moons, or Saturn with its rings—or a young or old crescent moon. In May 2017, special sessions will be held in daytime and at dawn to observe Venus at its brightest, in crescent phase. A session might include a bright flyover of the International Space Station.

It’s not too early to make plans for a very special event on Monday, Aug. 21, if you want to travel to see the event at its best: It’s a solar eclipse, visible throughout North America, and visible as a total solar eclipse within a narrow track across the U.S., tracking coast to coast from Oregon to South Carolina. Get to the path of totality if you can! Whether you do so, or you stay here at home to see the partial eclipse, the following web resources should help you prepare yourself and your family and friends for the event, and observe it safely.

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

eclipse.aas.org

eclipse2017.nasa.gov

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

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

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

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

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

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

www.greatamericaneclipse.com

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 and later astronomy and computer science at Michigan State University, and remains active in research and public outreach in astronomy.

In April 2017, bright and steady Jupiter is likely the first “star” to be spotted after sunset, south of east. Twinkling, blue-white Sirius, in the southwest quadrant, is next. Jupiter is at opposition to the sun, and above the horizon all night, on April 7-8; you can estimate the hour by noting the planet’s location—low in the eastern sky at dusk, high in the south in the middle of night, and low in the western sky at dawn.

As morning twilight brightens, we find an even more spectacular planet, Venus, rising in the east, as Jupiter slinks off toward the western horizon. Before dawn brightens too much, locate Saturn in the south.

Our evening sky chart plots daily positions of the brightest objects in the current month’s sky at mid-twilight. As April begins, the most-prominent objects, in order of brightness, are steady yellow-white Jupiter, climbing in the east to southeast as the month progresses; twinkling blue-white Sirius in the south-southwest to southwest; golden Arcturus ascending in the east-northeast to east, to the far left of Jupiter; and Capella, high in the northwest.

Sirius and Capella mark extreme south and north points of the huge Winter Hexagon, encircling Betelgeuse and Orion’s three-star belt inside. The belt points the way to Sirius, the Dog Star, and in the opposite direction, to Aldebaran, eye of Taurus, the Bull. In clockwise order around the hexagon from Sirius, locate Procyon, Pollux (with his fainter twin brother Castor nearby, not plotted), Capella, Aldebaran, Rigel and then back to Sirius.

Preceding the Hex across the sky in April 2017 is faint Mars, itself preceded by Mercury, as bright as zero-magnitude Arcturus on April 1, but fading to first magnitude by April 6, and very sharply thereafter. The trailing Pollux-Procyon side of the Hex crosses due south into the western half of the sky in twilight at the start of April. Following is Regulus, heart of Leo, reaching south at month’s end. Still farther east in April 2017, we find Jupiter, with Spica close by, and Arcturus.

The moon in evening sky: On the evening of April 1, the crescent moon, about one-third full, appears several degrees to the upper left of Aldebaran. The waxing moon, moving eastward, remains within the Winter Hexagon for two more evenings, but by April 4, the now-gibbous moon has exited (in a maneuver known as Hexit), appearing to the left of the Pollux-Procyon line. On April 6, the moon passes closely south of Regulus. On the evening of Sunday, April 9, the moon appears about 9 degrees above Jupiter, and on Monday, April 10, the full moon appears 3-4 degrees to the lower left of Jupiter. That evening, the moon rises about 17 minutes before sunset. Using binoculars, can you spot Jupiter in daylight to the moon’s upper right? As the sky darkens, notice Spica 7 degrees to the lower right of the moon-Jupiter pair.

After the full moon of early spring, the moon rises later and farther south nightly. On Tuesday, April 11, moonrise occurs at 7:52 p.m.; on April 12, at 8:47 p.m.; on April 13, at 9:41 p.m.; on April 14, at 10:34 p.m.; and on April 15, at 11:25 p.m.

The moon in morning sky: From the full moon onward, it may be more convenient for most folks to follow the moon at dawn. On Sunday, April 10, one hour before sunrise, find bright Jupiter low in the west-southwest to west, with Spica 7 degrees to its left. The nearly full moon will be 7 degrees to Jupiter’s lower right. On the next morning, April 11, the moon, just past full, will appear 7 degrees to Jupiter’s upper left. By Saturday, April 15, the waning gibbous moon will appear in the south-southwest, about 10 degrees above Antares. On Easter Sunday, April 16, the moon will appear closely to the upper right of Saturn in the south, and on April 17, farther to Saturn’s upper left. While you’re up early enjoying the moon and Saturn those two mornings, add to your total of solar system objects by spotting brilliant Venus low in the east before Jupiter sets in the west-southwest to west. Our morning twilight sky chart shows all these stars and planets, plus Arcturus in the west, to the upper right of Jupiter, and Vega, passing just north of overhead. High in the eastern sky, Altair and Deneb complete the Summer Triangle with Vega.

By the morning of April 19, the moon will reach last quarter phase, half full and 90 degrees or one-quarter of a circle west of the sun. After April 19, the moon is a waning crescent, closer to the sun each day.

On Saturday, April 22 there won’t be much moonlight to interfere with the peak of the Lyrid meteor shower, best in the hour or two before first light of dawn. To see the greatest number of meteors, observe from a dark place, and get most of your viewing in before 4:30 a.m.

On Sunday, April 23, moonrise occurs at 4:27 a.m., with sunrise at 6:05 a.m. Look an hour before sunrise, and you’ll see a 12-percent crescent moon very low in the east to east-northeast, 7-8 degrees to the lower right of Venus. Slight optical aid will reveal Venus itself is a crescent, 20 percent illuminated that morning.

The Venus-moon pairing on April 23 isn’t particularly close—the next one, on May 22, will be much tighter and more impressive—but this is the first of eight monthly predawn Venus-moon pairings through November.

On Monday, April 24, moonrise occurs at 5:06 a.m., with sunrise at 6:04 a.m., so look about 40 minutes before sunrise, at 5:24 a.m., to catch the last old moon, a 5 percent crescent, 3 degrees up just south of due east, and 11 degrees to the lower left of Venus.

Some special sights for binoculars:

1. Venus in April 2017 appears in crescent phase, less than 3 percent full on April 1, while nearly one arcminute across. One arcminute is 1/60 of a degree, and the moon is about a half-degree in apparent diameter, so a magnification of just over 30-power used to observe Venus at the start of April makes it appear as large as the moon is with the unaided eye! Even 7-power binoculars reveal a crescent if Venus is observed in bright twilight or in daylight. As weeks pass, Venus recedes from Earth and shrinks in apparent size, as the crescent begins to fill.

2. Star clusters, including the Hyades with Aldebaran in the foreground. Aim binoculars at Aldebaran, placing that bright star in the upper left part of the field, and other stars within the field will complete the V-shaped head of Taurus, the Bull. Those fainter stars belong to the Hyades, about 150 light years away, compared to Aldebaran at 67 light years. Also, find Pleiades, or Seven Sisters: This compact star cluster, located about 400 light years away, can be found in April’s evening sky about 14 degrees to the lower right of Aldebaran.

3. Jupiter’s Galilean moons: As many as all four of Jupiter’s satellites discovered by Galileo in 1610 can be spotted in binoculars very close to the planet. The brightest and easiest to see is Ganymede, the biggest moon in our solar system, larger than Mercury! In its seven-day orbit, this month find it farthest west of Jupiter on weekends, April 1, 8 and 9, 15 and 16, 22 and 23, and 30. Fainter, wider-ranging Callisto, in its 17-day orbit, appears farthest east of Jupiter on April 2 and 19, and farthest west on April 10 and 27. Slower-moving, it remains easy to see for about two days before and after these dates.

4. The thin crescent moon with earthshine. The moon returns to evening sky on Thursday, April 27. Your first chance to see the waxing crescent moon of the next lunar month will be at dusk on April 27, when the moon of age 39 hours will be very low, between the west and west-northwest. About an hour after sunset, look for the 4-percent lunar crescent to the lower right of Aldebaran, and lower left of Mars and the Pleiades. On Friday, April 28, the thicker 10-percent lunar crescent will appear a few degrees to the upper left of Aldebaran. On both evenings, and perhaps for a few more, note the faint, bluish illumination on the dark, non-sunlit portion of the moon. This is earthshine, from sunlight reflected from Earth.

Star parties provide wonderful opportunities to join with other folks who love to share their interest in observing the sky, and to get great views of astronomical objects through a variety of binoculars and telescopes. The Astronomical Society of the Desert will host the last of the season’s monthly public star parties at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument, on Saturday, April 1, from 7 to 10 p.m., and on Saturday, May 17, from 8 to 10 p.m. The Visitor Center is on Highway 74, within four miles south of Highway 111 in Palm Desert. Check www.astrorx.org for listings of our regular star parties and our high altitude star parties at Sawmill Trailhead starting at dusk. The next high-altitude star party (at 4,000 feet; wear warm clothes!) will be held on Saturday, April 22. Follow links to maps and directions to both star party sites.

Also, check the link to our “Impromptu Star Parties,” which could be announced on short notice at any time.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing skywatching 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.

This month’s selection of happenings includes the last evening and first morning appearances of Venus; the year’s most favorable apparition of Mercury; early evening moonrises; simultaneous views of planets low above opposite horizons (Mars-Jupiter and Mercury-Jupiter in the evening, with Venus-Jupiter in the morning); and a bright, far southern star, Canopus, reaching its high point very low over our southern mountains.

Venus is still very prominent in the evening sky as this month opens, setting in a dark sky 2 1/2 hours after sunset on March 1. By March 17, Venus sets just one hour after sunset, and by March 21, Venus drops below the horizon barely half an hour after sunset. By that date, Venus is already rising ahead of the sun, and it’s possible to observe it at both dusk and dawn for a few days. Through a telescope or even 7-power binoculars, the planet displays a crescent—best observed in daytime, or in bright twilight.

Our evening sky chart plots daily positions of the brightest objects in the sky at mid-twilight, when the sun is 9 degrees below the horizon, about 40 minutes after sunset. As March begins, the most prominent objects, in order of brightness, are Venus in the west; Sirius in the south-southeast; Canopus very low, just east of due south; Capella just north of overhead; and Rigel in the south. As March runs its course, Venus descends the near side of her orbit and drops below the western horizon, but not before Mercury climbs into view on the far side of his orbit. For a few evenings, both planets are visible. They appear closest to each other on March 18, with emerging Mercury passing 8.5 degrees south (to the lower left) of departing Venus. In the eastern sky just before month’s end, bright Jupiter rises a few degrees south of due east, while golden Arcturus rises in the east-northeast.

Sirius and Capella mark extreme south and north vertices of the huge “Winter Hexagon,” with Betelgeuse and Orion’s belt inside. The belt points the way to Sirius, and in the opposite direction, to Aldebaran. Preceding the Hex across the sky in March is faint Mars, itself preceded by Venus or Mercury, or both planets for a few days starting in midmonth. The trailing Pollux-Procyon side of the Hex reaches due south at mid-twilight at the end of March. Following them is Regulus, heart of Leo, Still farther east, we find Jupiter and Arcturus rising into view later in the evening, or by mid-twilight at month’s end.

In morning twilight: Jupiter, in the southwest to west-southwest as dawn brightens, ranks first in brightness, until Venus emerges north of east late in the month. Before the sky brightens too much, note Spica 4-6 degrees to the lower left of Jupiter. The most prominent stars are golden Arcturus high in the west-southwest to west, far to the upper right of the Jupiter-Spica duo, and blue-white Vega, very high in the northeast. Next in brightness is steady yellow Saturn, in the south-southeast to south. Look also for Altair and Deneb, completing the Summer Triangle with Vega. Find twinkling reddish Antares to the west and south of Saturn.

On March 1, the 15 percent crescent moon appears well to the upper left of Venus and a few degrees left of Mars. The moon climbs much higher each evening, and on Saturday, March 4, the nearly half-lit moon will occult, or cover, the bright star Aldebaran, with a sudden disappearance behind the moon’s leading dark edge slated for 7:12 p.m., and reappearance for 8:30 p.m. Binoculars and maybe even the unaided eye will suffice for the first event, but a telescope will be required to catch the star’s reappearance at the moon’s bright edge.

The moon continues to march eastward, passing between Procyon and the Gemini twins, Pollux and Castor, by March 7, and getting past Regulus, heart of Leo, by the evening of March 10. On Saturday evening, March 11, the almost-full moon rises at 5:14 p.m., still before sunset, which occurs at 5:51 p.m. Remember to set your clocks one hour ahead, and you won’t be surprised by Sunday’s later sunset at 6:52 p.m., and moonrise (just past full) at 7:13 p.m. After moonrise on Wednesday, March 15, look for bright Jupiter nearby, with Spica just a few degrees to the lower right.

With daylight saving time shifting our sunrises an hour later, predawn sky-watching becomes more attractive. Look an hour before sunrise on March 14 and 15 for the waning gibbous moon with Jupiter nearby, in the southwest to west-southwest. Spica is to Jupiter’s lower left. On the weekend of March 18-19, find reddish twinkling Antares near the moon in the southern sky, with brighter, steady Saturn to their left. On Monday morning, March 20, the moon, nearly at last quarter phase and just over half full, will appear closely to the upper left of Saturn. A telescope reveals the planet’s amazing rings, tipped nearly 27 degrees from edge-on this year, the greatest angle possible.

See Venus at both dawn and dusk for a few days! Around March 20, start trying to observe Venus rising before the sun, even though it’s still also visible in the evening, setting after sunset. Binoculars will reveal Venus as a large, thin crescent, as little as 1 percent illuminated on March 23-26.

On March 25, at 6:22 a.m., about 20 minutes before sunrise, find the thin (8 percent) old crescent moon 12 degrees up in the east-southeast. Locate Venus 32 degrees farther left and 10 degrees lower, or 10 degrees north of east and only 2 degrees up. This is the day Venus appears at inferior conjunction, an unusually wide 8.3 degrees north of the sun and 1 percent illuminated. On Friday, March 26, at 6:21 a.m., find the 3 percent crescent moon 12 degrees south of east and 4 degrees up.

The young lunar crescent first appears in the evening on Tuesday, March 28, around 7:29 p.m., nearly due west, just 5 degrees up and a few degrees to the lower left of bright Mercury. The next evening, March 29, look for the 5 percent crescent moon 40 minutes after sunset, 15 degrees up and to the upper left of Mercury. As twilight deepens, look for dim Mars about 10 degrees above the moon and a little right. By Thursday evening, March 30, the moon will climb to the upper left of Mars. Watch for Jupiter rising 7 degrees south of east just more than half an hour after sunset. Can you observe the three evening planets, Mercury, Mars and Jupiter, simultaneously?

The Astronomical Society of the Desert will host the next in our series of monthly star parties on Saturday, March 4, from 6 to 9 p.m., and on Saturday, April 1, from 7 to 10 p.m. They are held 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. Check www.astrorx.org. The next high-altitude star party at Sawmill Trailhead (at 4,000 feet—wear warm clothes!) will be held Saturday, March 25. Also, check the link to our “Impromptu Star Parties,” which could be announced on short notice at any time.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing skywatching 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.

Venus reaches peak brilliance, near magnitude -4.9, in February’s evening sky—giving rise to lots of UFO reports!

Through a telescope or even 7-power binoculars, the planet displays an ever-larger and thinner crescent, especially if viewed in daytime or at sunset. Venus appears 39 percent full and a half-arcminute across on Feb. 1, and only 17 percent full and 0.8 arcminute across by Feb. 28. (One arcminute equals 1/60th of a degree.) Try locating Venus in daylight when it’s highest and due south: On Sunday, Feb. 5, Venus is 59 degrees up at 2:44 p.m.; Feb. 12, 62 degrees up at 2:32 p.m.; Feb. 19, 65 degrees up at 2:16 p.m.; Feb. 26, and 67 degrees up at 1:55 p.m.

Find Venus easily with the unaided eye by sunset or shortly thereafter, 45 degrees to the sun’s upper left, on Feb. 1, to 33 degrees directly above the setting sun on Feb. 28. At dusk, Venus is in the west-southwest to west, getting lower as month progresses. Much fainter Mars (about magnitude +1.2) is 5 to 12 degrees to its upper left. Next in brilliance after Venus is the blue-white twinkling “Dog Star” Sirius (the brightest star, at magnitude -1.5) in the southeast to south, and next is yellowish Capella, the Mother Goat star, just northeast to north of overhead. Sirius and Capella mark extreme south and north vertices of the huge “Winter Hexagon,” with Betelgeuse and Orion’s belt inside. At the start of February, Regulus, heart of Leo the Lion, rises north of east over an hour after sunset. By Feb. 17, it rises at sunset and can be seen all night long.

In morning twilight: Jupiter, well up in the southwest as dawn brightens, ranks first in brightness in this month’s morning sky. Before the sky brightens too much, note Spica,about 4 degrees away. Catch bright Mercury very low in the east-southeast in the first week. The most prominent stars at dawn are golden Arcturus, high above the Jupiter-Spica duo, and blue-white Vega, high in east-northeast. Look also for Altair and Deneb, completing the Summer Triangle with Vega. Find steady yellow Saturn in the southeast with twinkling reddish Antares to its right.

Changes in predawn sky: In mid-February each year, the Earth’s orbiting motion carries us in a direction between the stars Spica and Antares, toward a spot in the sky 90 degrees west of the sun. As we face between those stars before dawn in mid-February, we are looking out the “front window” of Spaceship Earth. Go out an hour before sunrise and visualize how the motions of the Earth and other planets, orbiting at different speeds, will change the positions of planets and stars in our predawn sky. Speedy Mercury is now pulling away from Earth, and in early February sinks into the solar glare and disappears on the far side of the sun. On the night of February 17-18, our planet will pass between the sun and Regulus, and that star will appear at opposition, visible all night, low in the east at dusk, high in the south in the middle of night, and low in the west at dawn. Regulus appears lower in the west each morning.

As for the moon: On Tuesday, Jan. 31, the four-day-old waxing crescent forms a beautiful compact gathering with Venus and Mars. For the next few evenings, Venus and Mars remain 5.4 degrees apart. Meanwhile the moon moves on, passing widely south of the Pleiades (Seven Sisters) star cluster on Feb. 4; skipping past Aldebaran, eye of Taurus, by Feb. 5; getting by the Gemini twins, Pollux and Castor, by Feb. 8; and reaching full and rising at sunset on Friday, Feb. 10. That evening, sunset and moonrise occur simultaneously at 5:26 p.m. (assuming no mountains block the view), but that’s almost 45 minutes too late to catch the moon in deepest penumbral eclipse. Tell your friends east of the Rocky Mountains to look for a slight dusky shading covering the left or upper left part of the moon at 5:44 p.m. MST, 6:44 p.m. CST, or 7:44 p.m. EST. A much more impressive total lunar eclipse will be visible on Jan. 31, 2018—when Californians will have a great view!

A bit later in the evening of Feb. 10, watch for the rising of Regulus below the moon. The moon closes in on that star for the rest of the night, until dawn. On subsequent evenings, watch the waning moon rise later each night, farther south each time: on Feb. 11 at 6:28 p.m.; on Feb. 12 at 7:28 p.m.; on Feb. 13 at 8:26 p.m.; on Feb. 14 at 9:23 p.m. Or you can shift your viewing times to mornings, about an hour before sunrise. On the morning of Feb. 15, look for the beautiful gathering of the waning gibbous moon, Jupiter and Spica in the southwest an hour before sunrise. By Feb. 19, a fat crescent moon will appear above Antares, heart of the Scorpion. On Feb. 20, the one-third-illuminated lunar crescent will appear above Saturn, in the south-southeast. In morning twilight on Feb. 24, the 5 percent crescent is still easy to see, but very low in the east-southeast. Spotting the thin old 1 percent crescent, 25 hours before new, some 25-30 minutes before sunrise on Feb. 25, will be very difficult, requiring binoculars and very clear skies.

After new moon on Feb. 26 at 6:58 a.m., our first chance to see the waxing crescent will be at dusk on Monday, Feb. 27, when the 1.5-day old 3 percent moon will be very low, just south of due west, and far below and a little left of Venus. At dusk on Feb. 28, the 8 percent crescent moon appears about 10 degrees to the lower left of Venus.

The Whitewater Preserve will be hosting a star party on Saturday, Jan. 28, weather permitting, beginning at 6:30 p.m. Reservations are requested at 760-325-7222.

The Astronomical Society of the Desert will host the next of our series of monthly star parties on Saturday, Feb. 4 and March 4, from 6 to 9 p.m. They are held 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. Also, check www.astrorx.org for listings of our high altitude star parties at Sawmill Trailhead starting at dusk. The next high-altitude star party (at 4,000 feet—wear warm clothes!) will be Saturday, Feb. 18. Follow links to maps and directions to both star party sites, and for dates and locations of lecture meetings. The meeting at 7 p.m., Friday, Feb. 10, at the Portola Community Center in Palm Desert will feature astronomy author Dennis Mammana on “The Great American Total Eclipse: August 21, 2017.”

Also, check the link to our “Impromptu Star Parties,” which could be announced on short notice at any time.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing skywatching 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.

In January, Venus dominates the evenings! Find it in the southwest to west-southwest, with Mars to its upper left. In the west to west-northwest, find the Summer Triangle of Vega, Altair and Deneb. Vega is its brightest member, and Altair is the first to depart, around mid-month, if mountains don’t block your view. Fomalhaut, to the lower left of the two planets, may be easily overlooked.

The eastern sky is filling up with winter’s jewels! The “Dog Star” blue-white Sirius (the brightest star) and the Little Dog Star Procyon, preceding it, rise into view below Orion’s bright shoulder, red Betelgeuse, and bright foot, blue Rigel. (Sirius, Procyon and Betelgeuse form the nearly equilateral Winter Triangle.) Follow Orion’s belt downward to Sirius, and upward to orange Aldebaran, eye of Taurus, the Bull. To the left of Orion, look for Pollux (with Castor, 4.5 degrees away). Midway between Orion’s belt and the North Star, look for bright, yellowish Capella, the Mother Goat star.

Meanwhile, Jupiter ranks first in brilliance in the dawn sky. Find it well up in the south to southwest, with Spica only 4 degrees away. High above them is golden Arcturus, brightest star of January mornings. Regulus sinks lower in the west-southwest to west as the month progresses. Still lower in the west to west-northwest, the last stars of the “Winter Hexagon”—Procyon, Pollux and Capella—make their exits. Low in the southeast morning twilight to the lower left of Saturn, Mercury brightens to magnitude 1 on Jan. 5, and to 0 on Jan. 11. These planets approach to within 7 degrees on Jan. 9, widening to 26 degrees by Jan. 31. Find red twinkling Antares to Saturn’s upper right. Blue-white Vega, ascending in the northeast to east-northeast, ranks next after Arcturus in brilliance. Altair emerges low in the east at midmonth, completing the Summer Triangle.

The first evening of the New Year, Sunday, Jan. 1, features a beautiful crescent moon a few degrees to the lower right of brilliant Venus. Notice dim reddish Mars starting this month within 12 degrees to the upper left of Venus. On the next evening, find a slightly thicker crescent moon between Venus and Mars, closer to Mars. In early January in the Coachella Valley, sunset still occurs before 5 p.m., so 6 p.m. is a great time to enjoy these moon-planet gatherings.

By Thursday evening, Jan. 5, the waxing moon has reached first quarter phase, 90 degrees (a quarter-circle) from the sun, and appears half-full. On Sunday night, Jan. 8-9, from dusk until moonset (after 3 a.m. on Monday), watch the gibbous moon gradually creep closer to Aldebaran. On Wednesday, Jan. 11, the moon rises about 20 minutes before sunset. Full late that night, the moon passes several degrees south of the stars Castor and Pollux in Gemini. Each year late in January’s second week, our planet Earth passes between the sun and the Twins, causing those stars to remain above the horizon all night.

By Thursday evening, Jan. 12, the moon has passed full and rises about 40 minutes after sunset. Taking time out to watch moonrises with those you love can be relaxing and fun! Here are times for Palm Springs: Thursday, Jan. 12, at 5:38 p.m.; Jan. 13 at 6:42 p.m.; and Jan. 14 at 7:45 p.m. From the Coachella Valley, with our mountain surroundings, it might take several extra minutes until the moon’s disk becomes visible.

To continue following the moon, shift your viewing time to mornings. Within three hours after sunset on Saturday evening, Jan. 14, the waning gibbous moon rises closely south (to the lower right) of Regulus. The moon remains near that star for the rest of the night, with the pair moving into the western sky at dawn.

Jupiter, of magnitude -2 and well up in the south to south-southwest an hour before sunrise, rules the dawn. Note first-magnitude Spica move from 4.4 degrees from Jupiter on Jan. 1, to 3.6 degrees on Jan. 31. The moon, approaching last quarter phase, is in a beautiful grouping with Jupiter and Spica from about midnight until dawn on the morning of Jan. 19. (The pair remains separated by about 4 degrees from January into March.) That same morning, about an hour before sunrise, around 5:50 a.m., we find Mercury reaching greatest elongation, 24 degrees from the sun. Look for bright Mercury low in the southeastern sky, 12 degrees to the lower left of Saturn.

A waning crescent moon appears widely north of Antares on the morning of Jan. 23, and more closely north of Saturn on the morning of Jan. 24. A thin old crescent moon appears near Mercury on moon’s last two mornings, Jan. 25 and 26.

Back to the evening sky: The new moon occurs on Friday, Jan. 27, at 4:07 p.m. Spot the first young moonabout 25 1/2 hours later, soon after sunset on the next evening. From the Coachella Valley, begin looking around 5:35 p.m., when the hairline 1 percent crescent will be six degrees up in the west-southwest, only 12 degrees from the sun, and 34 degrees to the lower right of Venus. Three nights later, on Jan. 31, the four-day-old waxing crescent forms a beautiful compact gathering with Venus and Mars. Can you fit all three within a single field of view of your binoculars?

This month, Venus attains spectacular brilliance, magnitude -4.4 to -4.7, in the southwest to west-southwestern evening sky, and on Jan. 11-12, reaches greatest elongation, 47 degrees east or to the upper left of the setting sun. Can you spot Venus with an unaided eye before sunset? On Jan. 1, telescopes reveal Venus 56 percent illuminated, nearly 0.4 arcminutes in diameter. Before mid-January, Venus wanes to only half-lit (50 percent), and on Jan. 31, Venus is a crescent, 40 percent lit, but grows to 0.5 arcminutes across. Then Venus will nearly double in apparent size by late March!

The Astronomical Society of the Desert will host the next in our series of monthly star parties on Saturday, Jan. 7, from 5-8 p.m. They are held 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. Check www.astrorx.org for listings of our high-altitude star parties at Sawmill Trailhead starting at dusk. The next (at 4,000 feet—wear warm clothes!) will be held on Saturday, Jan. 21.

Also, check the link to our “Impromptu Star Parties,” which could be announced on short notice at any time. Coming events might include old and young crescent-moon watches at dawn and dusk; daytime and evening sessions to observe the crescent Venus; and sessions to observe flyovers of the International Space Station.

Whitewater Preserve will be hosting a star party on Saturday, Jan. 28, weather permitting, beginning at 6:30 p.m. Reservations are requested at 760-325-7222.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing skywatching 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.

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