Archive for January 26th, 2010


Mission 16: MARS!

January 26, 2010

Mission Objective: Planet

Equipment: Telescope

Required Time: 10 minutes

Related Missions: Ring of Fire

Instructions: Go outside after dark, face east, and look for a red star. It may help to get to Mars by way of the ring of bright seasonal stars that are also climbing the eastern sky on winter evenings.

On January 29, Mars will be at opposition, when it is directly opposite the sun from us. That means (by definition!) that it rises at sunset and sets at dawn, just like the full moon–in fact, you could say that the moon is full when it is at opposition. So you’ll have to wait a while after sunset before Mars will be very far up the sky. The best time to observe is when Mars is at the zenith and you’re looking through the least atmosphere possible, which happens around midnight.

For observers, the oppositions of Mars vary more noticeably than those of any other planet. The orbit of Mars is considerably more elliptical than that of Earth, so sometimes when we pass each other we are very close, and sometimes not so much–the Earth-Mars distance at opposition (when Mars is directly opposite the sun from us, and therefore as close as it is going to get on that pass) varies from about 35 million miles to something like 60 million miles. Right now we’re at the long end, and 2012 will be about equally as bad. The next close approach is 2018.

Still, Mars is as good as it’s  going to get for two years, so you might as well have a look. Last night I was able to see tantalizing detail at 92x in my six-inch reflector using a 13mm eyepiece. I put in a Barlow lens to double the magnification. Using that and the 3x optical zoom on my Nikon Coolpix 4500 digital camera, I got the shot at the top of this post, which is comparable to what I could see at the eyepiece. Here’s a labeled version:

The telescope inverts the image by 180 degrees, and I didn’t bother to flip it. Presenting planets southside up is pretty much the standard for solar system astrophotography, to the extent that the map of Mars in the December Sky & Telescope had the south at the top. That map is by expert solar system imager Damian Peach, and I used it to identify the features shown above. If you want to see some really mind-blowing shots of Mars and the other planets, check out Peach’s website. My Mars shot is pretty similar–in terms of part of the planet shown, not clarity!–to the second photo from the top on this page.

That’s all for now. Go explore the red planet. If you don’t have a scope or it’s too cold to set one up (one guy on Cloudy Nights posted a Mars shot he took on a night when it was -36C at his place in Russia!) at least go outside and have a look. Spirit and Opportunity are still up there, six years on. If you do see Mars, throw ’em a friendly wave, or maybe a salute. They’re doing us proud.