Want to be an astronaut one day? Consider becoming a teacher. Lots of people don't realize this, but all you need in order to be considered is a bachelor's degree in a STEM field and three years of experience — and teaching, even at the K-12 level, counts toward that experience. Sure, NASA tends to pick folks who have head-spinning combinations of advanced degrees and military flight experience, but technically your average high school chemistry teacher has a shot.

If you want to get a feel for how it would be to work as a surveyor on Mars, check out the map that cartographers at the British Ordnance Survey created in the same style they use for earthly locations. It makes the red planet seem like a great place to take a hike.

And NASA's call for farmers isn't just a cheeky shout-out to "The Martian." The space agency is working hard to figure out how to feed folks on long space missions. Astronauts on the International Space Station spent much of the past year experimenting with growing (and eating) lettuce in space, and now that they've successfully grown flowering plants they'll likely move on to more delicate crops such as tomatoes.

Growing plants on a Martian base will pose its own challenges, but there are already scientists on Earth trying to replicate the process with faux Martian soil.

The Journey to Mars campaign — which would have humans on the red planet in less than 20 years —might not be very realistic. There are a lot of technical hurdles to clear, and some say we haven't got the time or the funding to face those challenges. But NASA won't get more of the latter without public support, so you can't blame them for trying to get us amped for a trip that might not happen anytime soon.

And hey: Who says we're only allowed to be excited about exploring space if we're going to Mars?