Exogeology ROCKS!

The Mars Exploration Rover Spirit, as  you may or may not have heard, is STUCK. Rover operators have tried all sorts of maneuvers to get Spirit out of the sand, but nothing has worked. I’m amazed at how persistent the rover team is on trying to free the rover. They’ve tried going backwards, and using the robotic arm to move the sand around Spirit. Still no good. Two of the wheels aren’t working now either. I can’t believe Spirit is in such a bad position. Of course this means it can’t go anywhere or see anything new, but…

Even if the rover doesn’t get out it can still be useful in such a way that it was never intended to be! The rover team has become very inventive in what they’ve thought to do with Spirit. Mars wobbles, or “precesses“, as it rotates on its axis. A stationary probe (like the stuck Spirit) would be very useful in measuring how Mars spins. The rover team has thought of a plan of how to measure this.  This is how looking past your problems and working with what you have, rather than what you wished you had, can be a really important skill!

Why exactly would we care about Mars’ wobble? Because how a planet precesses is slightly different depending on whether it has a solid or molten core. Earth has a molten core, but if its core were solid then our own planet’s wobble would be different. Wouldn’t that be weird? Not to mention Earth wouldn’t have a magnetic field. Exogeologists (myself included) want to know what Mars’ core is like, so measuring precession would give very good information on the interior structure of Mars. I’d find out so much more about the planets if I knew this. It would help a lot in understanding the way they all work.

There’s only one problem. Martian winter is coming soon! This means decreased sunlight for the solar powered rover. I’m not an expert on robotics, but I do know that if Spirit runs out of power (its “spirit”), it’ll go into hibernation and use the little sunlight it receives for solely charging its battery. When it’s in hibernation, a rover can’t communicate with Earth. That could be a big problem, I think, for the team of rover operators and for myself. I get lots of good data from that rover! What’s more, the rover has survived three winters before this by tilting its solar panels northward in order to get the best angle to the sun. But doing this isn’t possible in Spirit‘s current predicament. I sure hope this can be fixed before the season changes!

I hope you thought this was as interesting as I did, and I’d like to officially wish the Spirit rover team good luck!

I’m Petra Stone, and Exogeology ROCKS!

Want to know just what an exogeologist does all day? Well, maybe I can show you just how cool this job is!

When I start working for the day, the first thing I do is see if I’ve received any new data. This could be from other exogeologists or from different spacecraft. I sometimes even get rock samples to analyze. If I do, I’ll take them to the lab. There I’ll test the sample to find out its composition.

There are lots of tests I can do. I can test minerals for streak, hardness, cleavage or fracture, and of course note the color and shape of the crystals. For example, let’s say I was given a mineral sample to identify. It has cube-shaped crystals, and is gold in color.  I rub it on a streak plate, and the streak is greenish black. I’ll scratch it with various tools and deduce that its Mohs hardness is 6. When I break it with a hammer, the place where it breaks is conchoidal (a distinctive curved shape). All these things put together tell me that my mineral is pyrite. If I were given a rock sample, there are a lot of various tests I could do to classify a rock, like cutting a thin slice and looking at it under a microscope.

• Here’s a quick tip about classifying rocks: If it has bubbles, it’s got to be igneous. Those bubbles are called vesicles, and they’re made when gas bubbles are trapped inside a rock as it cools.

Some days I’ll go to an observatory to do research on a planet. I need to reserve the telescope ahead of time usually. When I used a telescope at the Kitt Peak observatory, I had to reserve the telescope years in advance! But it was worth it. I got some great photographs of Jupiter and a comet during my time at the telescope. I’ve used lots of different observatories, and it’s always been productive. Well, except for that one time when it rained… I had to cancel. I must have been really unlucky that time. But that’s the trouble with astronomy; sometimes you just have to wait for another clear night. At least every other time went well.

Other days I’ll get information from a spacecraft or lander! That’s my favorite part! Once, I got to help with the LCROSS mission and interpret data from the spectrometer. The goal was to find water, and we did! That ROCKS! Since Mars is my specialty, I’ve been receiving data from the Mars Odyssey orbiter, which maps the amount of chemical elements and their distribution. I loved working on that. Maybe I’ll get to interpret data from the upcoming Mars Science Laboratory (MSL). Part of the MSL’s mission will be to study the geology of Mars.

Exogeology ROCKS!