The first full moon of 2010 rises tonight at sunset. Through breaks in the clouds, look for the full moon rising in the east just as the sun sets. Look to the left of the moon to see Mars riding along side. Mars will appear modestly bright and shamelessly red.
If the sky doesn’t clear until later in the evening, look for the moon and Mars high overhead after midnight. But, it will take a hearty soul to be outside in the middle of the night in the middle of winter. The forecast calls for mostly cloudy skies and the coldest temperatures of the year so far.
As it happens, tonight is the best night in quite some time to catch a glimpse of the Red Planet: Mars and earth are as close as they get through the cycle of their orbits around the sun.
When we see an outer planet (a planet further from the sun than earth) rise when the sun sets, we know that earth lies directly between that planet and the sun. In this configuration, a configuration astronomers call opposition, earth and the planet in question are as close as they can get.
Earth slides between Mars and the sun once every two years and two months.
Tonight, as Mars is at opposition, the distance between earth and Mars is just under 62 million miles (100 million km), or about two-thirds of the distance between the earth and the sun.
The apparently much larger moon at Mars’ side is, however, merely 220 thousand miles away.
Don’t be fooled by how big the moon appears. Mars is actually about half the size of earth, which makes it about twice the size of the moon (because the moon is about one-fourth the size of earth). The moon appears so big compared to Mars because tonight it is almost 300 times closer to earth than Mars.
To get a real good view of Mars you’ll need a small telescope. And even then, you’ll need to use your imagination if you hope to see features on its surface. The plain fact is: it’s hard to see something—even when it’s half the size of earth–when it’s 62 million miles away!
What’s happening on Mars these days? The big news is that Spirit, one of NASA’s little rovers which has been wheeling around on Mars for six years now, recently became stuck in a sand trap.
All attempts to free Spirit have failed, but it’s not the end of the road for this intrepid robot. Most of Spirit’s tools, sensors and cameras are still working, and NASA scientists and engineers will continue to put them to use to investigate and monitor Spirit’s environment in detail.
Spirit drove a total of 4.8 miles on the surface of Mars before becoming stuck.
The better news is that Opportunity, Spirit’s charmed twin, continues to operate as flawlessly as can be expected in the harsh Martian climate. Opportunity has driven 12 miles and shows comparatively few signs of decline. NASA scientists and engineers are presently directing Opportunity to circumnavigate and extensively photograph a 10-meter diameter crater named “Concepcion.”
For updates on the status of the Mars Exploration Rovers, visit http://marsrover.nasa.gov/.
What a wonder it is to look at Mars on a cold winter evening and think about all that is going on up there, 62 million miles away.
This article originally appeared in the Grand Haven Tribune on 29 January 2010.
