Moon and Mars
Published on Dec 23, 2007 at 3:13 pm.
5 Comments.
Filed under skywatching.
Tonight, if you go outside in the northern hemisphere, you’ll see the Moon and Mars very close together. The Moon moves its own with each hour. Over the course of a day, it moves about as far across the sky as the width of a hand held at arm’s length. So, last night, the Moon was west of Mars, and tomorrow night it will be east of Mars. Tonight they pass one another (at about 9pm Central time). In fact, if you go out an hour or two before and after, you’ll be able to clearly see that the Moon has moved with respect to Mars. This close passage of one celestial body past another is called a conjunction. I created a view of the Moon and Mars as they would appear from here in Texas. If you are east of here (say, in Florida), then it would appear higher in the sky. If you are west of here (as in Colorado), then it will be closer to the horizon. Too far to the west and you’ll miss the closest approach altogether, since it will happen before Mars and the Moon rise.
Interestingly, the perspective that you see on the conjunction will depend also on your latitude. That is because the Moon is vastly closer than Mars. So, from different latitudes, the Moon will appear slightly farther north or south in the sky. This conjunction is particularly close. In fact, it is so close that if you are far enough north, then you’ll even see the Moon pass in front of Mars. That sort of event is called an occultation. You would be able to see the Moon occult Mars if you were in northwest Canada, Alaska, northern Russia, the Arctic, and part of far northern Europe.
As interesting as the Moon and Mars conjunction, it is also interesting to note that several other things are happening right now with the Moon and Mars. The Moon is Full tonight. Full Moon occurs when the Moon is opposite the Sun in the sky. But, the Winter Solstice was just days ago, on December 22. On that date, the Sun appears as far south as possible in the sky. This means that the Moon is currently almost as far north as it can get in the sky, being about 28 degrees north of the celestial equator. Another interesting fact is that the Moon, which has an elliptical orbit, was closest to Earth just yesterday, making it appear slightly larger than normal. And there’s even more! Mars is at opposition on December 24. On that date, Mars will be as close to opposite the Sun as it will get this year. You can think of it as the day that Earth passes Mars in its orbit. In an interesting footnote to that piece of information, though, is that Earth and Mars were actually closer together a few days ago, on December 19, than they are today. This is because of how the orbits of Earth and Mars are orientated. Earth is currently heading towards its closest distance to the Sun (which will be in early January), and Mars is on its way towards its farthest distance from the Sun.
It is interesting that the Moon and Mars are at such a close conjunction at a time that all these other things are going on with the Moon and Mars. But, don’t make too much of that, because there are always things going on with the Moon and planets. Therefore, it isn’t really abnormal for a conjunction to happen when other things are happening. Still, this is a bit more going on than normal, and at least for me, that makes this an interesting conjunction.
So, if you get clear skies tonight, go out and take a look at this rather unusual set of circumstances.
-Astroprof
(Image produced using Stellarium)
Kelly on December 23, 2007 at 6:22 pm: 1
Absolutely love all the information and will continue to check back. Glad I found your site tonight. I was just outside and the moon and mars were so beautiful that I wanted to find out more!
Thanks!
Caroline Crow on December 23, 2007 at 7:44 pm: 2
Awesome site. We were driving around with our kids looking at Christmas lights and up in the sky something was big and bright next to the moon!
Thanks for providing the info!
Keith on December 23, 2007 at 10:23 pm: 3
This is really cool! Thanks for the tip Astroprof
I just recently bought a telescope on sale from Amazon, so I feel pretty lucky to have this chance in my first few days of stargazing. I was also able to find Orion close by (one of the oh about three or so constellations I’ve learned so far… it’s a start though!) Thanks for the informative posts. Keep up the good work!
Emily on December 23, 2007 at 11:59 pm: 4
I knew it was Mars! My fiance thought it was the space station. Thanks for solving a puzzle, I was sure this was a planet, and the color said it had to be Mars.
erika on December 26, 2007 at 4:24 pm: 5
Wow! Thank you very much for this information! I was able to see and image Mars and Moon conjunction, Mars at opposition, and the moon’s change in position with respect to Mars!
This really made my Christmas season special! Thank you very much! 