From early March through early June 2016, the Earth will overtake all three bright outer planets within just 87 days, with each planet reaching peak brilliance and all-night visibility: Jupiter in early March; Mars in late May; and Saturn in early June.
For several months following these oppositions, each respective planet will remain conveniently visible in the evening sky … at last!
What does opposition mean? When at opposition as seen from Earth, a planet appears at or nearly 180 degrees from the sun, and appears on the opposite side of the sky from where the sun is located. Thus, the planet will be up all night: low in the eastern sky at dusk, high in the south in the middle of the night, and low in the western sky at dawn. Near the date of its opposition, a planet reaches its closest approach to Earth, and its peak in brilliance.
For several weeks through late February, early risers enjoyed a wide panorama of all five naked-eye planets across the morning sky. Nine folks joined us for our viewing on Feb. 7 to revel in views of five planets, Jupiter’s moons and Saturn’s rings, and a rising old crescent moon just 24 1/2 hours before new. Thanks for coming out!
We’re now starting to offer informal Impromptu Sky Watches or Neighborhood Mini Star Parties. Most will occur in the evening. Check this story for some listings. Hope to see you there!
Mornings in early March: If the mountains don’t block your view, it’s still possible to catch Venus low in the east-southeast, and Jupiter low in the west simultaneously, while Saturn, with brighter reddish Mars nearby to its right, adorns the southern sky. Between Mars-Saturn and a little lower, look for the reddish star Antares, heart of the Scorpion. The light of Antares is more noticeably affected by Earth’s atmosphere, causing it (and other stars) to twinkle.
In the mornings as March progresses, Venus and Jupiter sink toward opposite horizons, with Venus heading toward its June 6 superior conjunction on the far side of the sun, and Jupiter reaching opposition to the sun on the morning of March 8 as Earth overtakes it. That morning, with Jupiter in the west, the sun below the eastern horizon, and Saturn in the south just more than 90 degrees west of the sun, we can visualize our counterclockwise revolution around the sun and the forward motion of our Spaceship Earth toward Saturn. Venus, moving faster, is leaving us behind, and we are passing Jupiter, causing it to drop from sight in our right (west) window.
March evenings: Theyare rich with bright stars and planets. Jupiter, rising in the east, is the first of several planets to grace the sky at dusk in coming months. Dog-walkers and others out and about regularly at dusk will be rewarded with many striking astronomical sights this spring. At dusk on March 7 (early during the night of Jupiter’s opposition), we have the sun below our western horizon, and Jupiter visible in the east. Now we’re looking out the rear window of Spaceship Earth. On March 7, we’re moving away from a point in Taurus, about 8 degrees east-northeast of Aldebaran. Faster-moving Mercury will emerge from beyond the sun and have the year’s most favorable evening apparition in the western sky at dusk in April, before it transits the sun on May 9.
Our charts depict the sky at mid-twilight, which we define as the moment when the sun is 9 degrees below the horizon. During March, in the Coachella Valley, mid-twilight occurs about 40 minutes before sunrise (effectively concluding your sky watch, as stars and planets fade in the brightening dawn), or 40 minutes after sunset (a fine time to start your evening viewing, as stars and planets become easier to find in the fading light of dusk).
Sky events in morning twilight
March 1: The moon, just more than half full in the south, is approaching last-quarter phase. Mars is 9 degrees to the lower right. Saturn is 9 degrees to the lower left, with Antares 9 degrees below the moon and nearly 9 degrees to the lower right of Saturn.
March 2: The moon is 4-5 degrees to the upper left of Saturn.
March 3: Venus and Jupiter are 150 degrees apart.
March 7: The old moon, about 1.5 days before new, is visible near Venus for the last time in the planet’s morning apparition; Look 4 degrees to the left of Venus.
March 8: Jupiter is at opposition! Spaceship Earth now overtakes the giant planet. We are heading about 2 degrees left of Saturn. As we follow our curved orbit around the sun, we will overtake Mars on night of May 21-22, and Saturn on night of June 2-3.
March 9: Mars and Saturn are 15 degrees apart.
March 23: Before Jupiter sets, the three bright outer planets, in order from west to east—Jupiter, Mars and Saturn—span 90 degrees.
March 27: Mars and Saturn are 10 degrees apart. They’ll be separated by no more than 10 degrees through May 12, and will be as close as 7.2 degrees apart April 16-23.
Sky events in evening twilight
March 7: Jupiter is at opposition tonight as Spaceship Earth overtakes it. We are now moving away from a point in Taurus about 8 degrees east of Aldebaran.
March 9: The first waxing crescent moon, age 24-25 hours is low, 3-4 degrees south of west.
March 13: The moon is below the Hyades star cluster and Aldebaran at dusk.
March 14: The moon is east of Aldebaran at dusk.
March 15: The moon is north of Betelgeuse at dusk.
March 17: The moon is east of the Pollux–Procyon line at dusk.
March 19: The moon is to the upper right of Regulus at dusk. Spring begins at 9:30 p.m.! A Star Party is hosted by Astronomical Society of the Desert; www.astrorx.org
March 20: The moon is to the lower right of Regulus at dusk.
March 21: The moon is 2 degrees south of Jupiter, now 165 degrees from the sun, at dusk. Note the moon’s phase as it passes Jupiter in the evening sky every 27-28 days this spring and summer, until the last pairing, with a thin crescent moon, on Sept. 2.
March 23: Mercury is at superior conjunction, hidden on the far side of the sun. In 7-10 days, using binoculars half an hour after sunset, try to find it very low in the bright twilight glow, north of west. In first three weeks of April, Mercury will be easy to find with the unaided eye.
A YouTube video showing a view of the morning twilight sky from mid-October 2015 until early March 2016, followed by a view of the evening twilight sky from early March through late October 2016, is available here.
Illustrations of aforementioned events appear in the Sky Calendar. For a sample issue and subscription information, visit www.abramsplanetarium.org/skycalendar.
The Astronomical Society of the Desert will host a star party on Saturday, March 19, from 7-10 p.m., at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument. Get info on future star parties, with directions and maps to the two sites, as well as news on lectures and special events, at www.astrorx.org
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, who provided the twilight charts and the planet orbit charts, 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.