Bad Astronomy

Mars and the Moon Monday night

On Monday night, the Moon (which will be just past full) will be very close to Mars in the sky. They’ll be separated by about a degree, or twice the Moon’s width. It should be very pretty, so go take a look! Around 9:00 p.m. (your local time) go out and face east, and they should be high enough to see unless you have a really bad horizon.

Mars is getting very bright these days as the Earth catches up to it in their racetrack paths around the Sun. We’ll be closest to the Red Planet on December 18th, when it will be about 88 million km (55 million miles) away. Right now it’s about 96 million km (60 million miles) away. Still, it’s shining brightly even now, and worth a look. After the Moon moves away in a couple of more days, go take another look to see just how brilliant it is in the dark sky.

When all is said and done, this is not one of Mars’ better apparitions, actually. It was much closer in 2003, for example, so don’t expect it to look huge and looming in the sky. Through a very good ‘scope you’ll be able to see some surface details, but not much. Mars is small, and 100 million km is still a long, long way away. But don’t sweat it: in a couple of months, Saturn will also appear in the night sky shortly after sunset, and the ringed planet never disappoints.