The moon will be in a line with Venus and Saturn to start the new year. New moon was just two days before the year began though. If you can’t spot such a young moon so soon, wait until the next night. The best view of the thin crescent on Wednesday evening the 1st will be from low latitudes. But the objects are more evenly spaced on Thursday evening the 2nd, so that may be the best view from practically everywhere on Earth. Then we get the Venus-moon pairing on Friday the 3rd when they’re 1.3° apart. And the moon’s 0.6° from Saturn on the 4th. Much of Europe from the continent to Iceland and the east coast of Greenland get an occultation.
All this time and for two more weeks, Venus is moving farther eastward among the constellations toward slowly moving Saturn. Venus reaches greatest elongation, 47.2° east of the sun, on the 10th. While the planet’s angle from the sun is decreasing, it continues moving eastward among the stars behind it. What’s actually happening after greatest elongation is the sun’s moving eastward faster than the planet. Venus moves on toward Saturn and they’re at their closest, 2.2° apart, on the 18th. That’s too far apart to use magnification high enough for seeing both planets’ disks in the same telescope view. But binoculars and low magnification telescope views will show them as bright dots—Venus much brighter, of course.
Venus continues climbing, moving up alongside the western fish head of Pisces in the last days of January. On the 31st, Venus is 3.3° from Neptune. Venus is right of Neptune, but a telescope view may flip them depending on the optics. And you will need a telescope to see Neptune. The moon, having completed its circuit will be in the evening sky again and will be close to these planets on February 1st.
Saturn spends all month slowly moving eastward against the stars in Aquarius. Its elongation is also shrinking from 62° at the start of January to 35° at the end of the month.
The moon reaches first quarter in Pisces on the 6th. Then it passes Uranus on the 9th and then the Pleiades on the 10th. Observers in far northwest Africa, western Europe, the northern Atlantic, southern Greenland, and most of North America can see the moon right in front of the Pleiades on the evening of the 9th local time or morning of the 10th local time. Shown above is a visibility map specifically for the Pleiades member Alcyone.
The moon’s near Jupiter on the 10th. The big planet is partway up the eastern side of the sky dome at dusk for most observers this month. It’s moving retrograde (westward) in the region of the Hyades this month. It’s on the Ain side of the asterism. As January ends, Jupiter slows down. It’s about to resume direct motion on February 4th.
Meanwhile, Mars is also retrograde. It starts January halfway from Cancer to Gemini. It’s entering Gemini near Pollux when the full moon is close by on the 13th. On the evening of the 13th local time for the Americas and morning of the 14th for most of the Atlantic and Africa, the moon passes in front of the red planet. The occultation will be visible from most of Mexico, the continental United States, much of Canada, much of the northern Atlantic Ocean, and western Africa.
This is a good month to view Mars. The planet is closest to us on the 12th and at opposition on the 14th. Its distance will be 0.64 astronomical units (earth-sun distances). While it’s up all night, you can try to see for yourself how long Martian days are, if you have a telescope with sufficient magnification and if dust storms on the planet don’t prevent you from viewing surface features. You’ll see features in the same place about 38 minutes later each night. Thus, we conclude the Martian day is about that much longer than ours. If you want a math challenge, you can calculate how much Earth and Mars move in their orbits from night to night and determine more precisely the apparent rotational offset.
Mars is closest to Pollux, 2.4° from it, on the 22nd. It ends the month on the Pollux side of Gemini, still heading deeper into the constellation.
Mercury is a morning object this month. As is typical for the messenger planet, it gets progressively harder to see as it heads toward the sun. The planet is at the feet of Ophiuchus at the start of the month and makes it into Sagittarius a little over a week later. It’s close to Kaus Borealis, the northern bow star, on the 12th and 13th. The moon passes by it late on the 28th, but by that time, both will appear too close to the sun for anyone to see them. The best views of Mercury this month are from low latitudes.
A waning gibbous moon will pass 2° from Regulus on the 16th. Then on the 21st, it occults Spica for observers in western Africa and parts of the Atlantic. Last quarter phase is later on the 21st. And we have an Antares occultation on the 25th. That’s visible from northern Madagascar and the Indian Ocean.
The moon’s new on the 29th and reemerges in the evening sky for the aforementioned next meeting with the evening planets on February 1st.
The Quadrantids meteor shower peak is expected on the 4th. The meteors have been linked to asteroid 2003 EH1.
