Looking Up: The God Of War Is Getting Rusty

Jul 30, 2018

Since the distance from Earth to Mars changes drastically as the planets orbit the Sun, Mars' appearance changes dramatically. Mars is bright now, and it's getting closer and brighter still as it orbits toward its 2018 opposition and closest approach to Earth in late July.
Credit Damian Peach, Chilescope team / nasa.gov

This week Mars will be as big as the full moon (as long as it's viewed through a telescope at about 100x magnification).

There’s a rusty planet up on the Southern Colorado sky right now that is definitely worth taking a look at, because you’ll won’t see it this well again until 2035. I’m talking about Mars, and as it turns out, the orbits of Mars and the Earth are such that right now, Mars is about as close as it ever gets to Earth. In more “normal” years, so to speak, Mars is still a pretty thing in a telescope. With decent optics, you can make out the frozen pole and some dark places on the surface. With Mars so close, we should get even better views.

That is, of course, if Mars cooperates. Right now, Mars is having a dust storm that covers most of the planet. While Mars’ atmosphere is far thinner than Earth’s – only about 1% as thick – that is still thick enough for weather and winds that kick up fine dust particles. But these storms aren’t all bad. Mars is the only planet in the Solar System entirely populated by robots. And these robots have solar panels to charge their batteries. More than once, a small dust devil of Martian wind has blown across various spacecraft and, well, cleaned off the solar cells. Thanks Mars. Oh, and that red color? That’s because Mars is, quite literally, rusty. Ancient oxygen and water made the iron-based rocks, rusty. So grab a can of WD-40 and head for the rusty planet that is close by! 

A self-portrait of NASA's Curiosity Mars rover shows the robot at a drilled sample site called "Duluth" on the lower slopes of Mount Sharp. A Martian dust storm reduced sunlight and visibility in Gale Crater.
Credit NASA/JPL-Caltech/MSSS / nasa.gov

If you’d like to take a closer look at Mars, or any of the other wonderful and amazing things in the sky, please visit csastro.org for a link to information on our monthly meetings and our free public star parties.