Planets on the Horizon

Saturn continues to be the main planetary show through February. The ringed planet reaches opposition on February 10, climbing to 68 degrees above the horizon when it transits around midnight. The rings are tilted just short of fourteen degrees, with the southern side pointed our way.

Earlier in the evening, Venus gleams in the twilight throughout the month. As February opens, Mercury sits nearby, but it wanes to invisibility by mid–month. This is a good chance to chase the elusive crescent Mercury if you have access to a good western horizon: it’s easy to spot the planet during the first week of the month, then once you’ve found it, follow it each night and watch how fast it grows, wanes in phase, and moves lower and closer to the sun. You’ll be surprised at how much change you see in only a day!

A dedicated planet hunter might be able to catch Uranus as well, more or less midway between Mercury and Venus in the evening sky. The dim sixth magnitude planet won’t be easy to spot in the twilight — is it possible to see it at all, with Mercury and Venus as a guide? It’s all the more challenging because it’s in Aquarius with no particularly bright stars nearby, but it sounds like an interesting challenge! Meanwhile, Neptune is out of the running, too close to the sun to be visible this month.

Jupiter and Mars are both morning objects this month, with Mars visible only near dawn. Jupiter rises several hours after midnight, but never gets very high in the sky before daylight hides it. Faint Pluto, too, is in the dawn sky, a very difficult target for anyone but the most determined Plutocrat. You’ll have a much easier time in a few months.

But there’s another way to view at least one of those morning planets: the Pluto–bound New Horizons spacecraft will have a close encounter with Jupiter at the end of February, with closest approach on the 28th. It last photographed Jupiter in September, from quite a distance, but starting in late January we should start seeing some nice photos of Jupiter “up close and personal” as the spacecraft dives in to the giant planet in order to get some gravity assist on the way out to Pluto.