january ’25 – rick’s picks

All month: the solar system is primarily an evening show again this month. Mercury is one of the exceptions: its gibbous disk graces the morning sky for the first half of January, shrinking from 6 to 5 arcseconds in size and fading from mag -0.4 to -0.3 along the way. It then disappears into the solar glare on its way to superior conjunction on Feb 9. Venus remains an evening star, setting at 8:19 pm on New Year’s Day and 8:55 pm at month’s end, brightening from mag -4.5 to -4.8 and growing from 22 to 31 arcseconds as its slightly gibbous phase slowly becomes a fat crescent. Dichotomy is expected on Jan 11, but can vary by up to 4 days in either direction, so keep an eye on it and make your own judgment of when it happens. Mars puts on both morning and evening shows, reaching a fairly undistinguished opposition on Jan 15 at mag -1.4 with a smallish disk diameter of 14.6 arcseconds – not spectacular, but adequate to see major surface features like the northern ice cap even in 3” scopes. By month’s end it’s down to mag -1.1 and 13.8 arcseconds. Syrtis Major is well-positioned for views from Jan 21-31; use Sky & Telescope’s Mars Profiler at https://is.gd/marsprofiler to see what’s visible at other times. Jupiter remains exclusively an evening show, rising in early afternoon, then setting after 5 am on Jan 1 and two hours earlier on Jan 31. It fades from mag -2.7 to -2.5 and shrinks from 47 to 43.5 arcseconds during the month. Jove continues to chase Uranus across the sky, with the blue planet maintaining a 90 minute lead, its 4 arcsecond disk glowing at mag 5.7. Saturn begins its slow exit from the evening stage, setting around 9:45 pm as January opens but right at 8 pm as it ends, its 16 arcsecond disk framed by nearly-flat rings and glowing at mag +1.1 all month long. It’s our last month to see Saturn in the evening for awhile, and our last view of the north side of Saturn’s rings until 2039. Neptune follows just about an hour after Saturn, at mag 7.9 with a 2 arcsecond disk. Among the asteroids, 15 Eunomia remains reasonably bright as it wanders the borderlands of Taurus and Auriga following its opposition last month. This month’s charts will show you where to find it.
Jan 2: look SW after sunset (around 4:30 pm CST) to see a gorgeous 3-day crescent Moon slipping towards the horizon with bright mag -4.5 Venus following 10° behind – and as the sky begins to darken, look for mag +1.1 Saturn traipsing along even farther back, 15° behind Venus. After that, check out Jupiter in the east, where the shadow of Io began a trek across the face of the planet just after sunset and will end it at 6:52 pm. Io itself started out even earlier, and will complete its transit at 6:12 pm. At 6:00, watch for Ganymede to pop out from behind the planet’s NW limb – but look quick, because at 6:26 it will disappear into the big planet’s shadow until almost 9 pm. Later tonight, long after the Moon has set, the Quadrantid meteor shower peaks under excellent observing conditions in the pre-dawn hours, when its 120 ZHR will translate to 25-30 meteors per hour – and since the Quadrantids are fast-movers, with more than their fair share of fireballs, that could be a nice show. The only drawback is the shower’s short peak: it remains at 50% maximum for only a half day.
Jan 3: it’s a good day to spot Venus in the daytime sky. At 3:30 pm CST, the thin 4 day old crescent Moon will be due South and 35° above the horizon. Venus will be just 3° to its right and slightly above it. Being careful to
avoid the Sun (which will be low in the SW sky), find the planet with binoculars, then give it a try naked-eye once you know exactly where to look. They’ll continue to be a pretty pair until Venus sets shortly after 8 pm.
Jan 4: tonight it’s Saturn’s turn to escort the crescent Moon down to the horizon. Look for the pair any time after 5 pm CST, with Saturn leading the way by 3°.
Jan 6: pretty blue Europa strolls across the face of Jupiter from 7:26 to 9:57 pm CST, followed by its shadow from 8:53 to 11:27 pm. Meanwhile, at 8:10 pm, mag 4.3 star Epsilon () Piscium disappears behind the dark limb of the first quarter Moon. Start watching at least 10 minutes before that so you don’t miss anything.
Jan 9: Venus reaches its greatest eastern elongation for this apparition, 47° from the Sun, and sets nearly 4 hours after our local star. Meanwhile, you’ll need binoculars to watch the gibbous Moon march into The Pleiades (M45) like an invading army, and make one star after another disappear behind its dark edge: mag 3.7 Electra at 6:12 pm CST, mag 4.1 Merope at 6:14, mag 2.9 Alcyone at 6:55, mag 5.1 Pleione at 7:51, and mag 3.6 Atlas at 7:53. Meanwhile, Io does its own march across the face of Jupiter from 5:47 to 7:59 pm, followed by its shadow from 6:35 to 8:47 pm, and Ganymede does a disappearing act, passing behind Jove’s disk at 7:17 pm, popping back out at 9:26 pm, then hiding in the planet’s shadow from 10:27 pm to 12:46 am.
Jan 10: the gibbous Moon forms a straight and evenly-spaced line with Jupiter and Aldebaran (Alpha [] Tauri) across tonight’s sky, like a magnified and mirror-reversed version of Orion’s Belt.
Jan 13: Castor, Pollux, and a close pairing of the Moon and Mars form an almost perfectly straight and evenly-spaced line as they rise through the eastern sky tonight. Then at 8:07 pm CST, Mars will slip behind the bright edge of the almost-full Moon, reappearing from behind its paper-thin dark limb at 9:16 pm. You’ll need binoculars to see the disappearance. It’ll take a telescope to get a good view of the two orbs’ contrasting colors, and to watch the planet peek out from behind lunar mountains and crater rims as they pass by.
Jan 17: mag -4.6 Venus slides towards the horizon with mag +1.1 Saturn just 2° to its lower left tonight and tomorrow. You’ll need binoculars to see them both, since Venus is almost 200 times as bright as Saturn. Meanwhile, Mars forms a straight line with Castor and Pollux, seeming to become part of the Winter Hexagon and turning The Twins into triplets. It will stay within a couple degrees of Pollux for the rest of the month.
Jan 19: look SW starting around 5:15 pm CST (a half hour after sunset) to see if you can spot mag +1.1 Saturn sheltering just 2½° below left of bright (mag -4.4) Venus as the pair head towards the horizon.
Jan 23: Io transits Jupiter from 9:24 to 11:35 pm CST, followed by its shadow from 10:26 pm to 12:38 am.
Jan 27: Ganymede crosses Jove from 4:15 to 6:27 pm CST, followed by its shadow from 8:38 to 10:58 pm.
Jan 30: New Moon arrived yesterday at 6:36 am CST, and at 5:34 pm tonight (a half hour after sunset) it will be 35 hours old, 2.6% illuminated, 9½° above the horizon, and 6° left of the spot where the Sun went down. You’ll have nearly an hour to spot it before it sets at 6:29 pm.
Jan 31: look for a pretty sight in the SW sky beginning around 5:36 pm CST (a half hour after sunset), as Saturn sits just 3° above left of a 7% illuminated crescent Moon, with Venus looking on from above the pair – then watch the shadow of Europa walk across Jupiter from 5:57 to 8:32 pm. As a bonus, Io slips behind Jove at 8:31.

Rick Gering / January 2025