There are seven active deep-space missions that frequently post fresh images to the Internet. I’ve featured images from the Curiosity rover and Cassini Saturn orbiter here before; here’s an image from another mission, Lunar Reconnaissance Orbiter. LRO (as acronym-happy NASA folk call it) started out its life being run by the human exploration side of NASA; the “reconnaissance” in its name was the advance scouting for landing sites for future astronauts. America has backed down from these ambitions, but the spacecraft continues to function at the Moon, and is now operated by the science side of NASA.

Lunar Reconnaissance Orbiter took this photo about a year ago; I selected it from their gallery because it shows a curious feature — different-colored crater splats — that we’ve been noticing on lots of other worlds recently, including the asteroid Vesta and planet Mars.

Here’s a closer look at those dark-splat craters. When you zoom in, you can see that the story is more complicated than a dark splat on top of a lighter surface. The biggest crater (it’s about 50 meters across) looks kind of like a snow angel, with some darker rays but also some lighter rays. I look at this and ask: what the heck happened here? Something smacked into the surface, something around 5 or 10 meters across, and that’s what made the crater, but why the dark rays and the light rays in those particular places?

If you read the caption that the Lunar Reconnaissance Orbiter camera team posted with the photo, you might think you’ll get the answer. Instead, you’ll discover that the real pro scientists (in this case, James Ashley, a postdoc at Arizona State University) are asking exactly the same questions.  Unlike a lot of missions, the LROC team doesn’t give you pat explanations with all their image releases. There is some explanatory information, but the captions quickly move beyond that, encouraging you to think like a geologist, to ask the very same questions that scientists do, and to explore the pictures for yourself. This is one reason I love planetary exploration so much: a lot of the time, the questions that the professional scientists are asking are the very same ones you might ask. It’s easy to understand and identify with the intellectual curiosity that stimulates the scientists!

The pictures taken by LRO’s camera instrument are awesome, more detailed than any images of the Moon taken since Apollo astronauts got close enough to photograph themselves there. LRO is not one of those missions that puts raw data on the Internet in near-real-time, but they are among the fastest at releasing their archive-quality data. Once every three months, they release everything acquired between three and six months previously. It’s a lot of data — about 30 Terabytes every 3 months, and that’s just the images. You can browse it all through a map interface here, or dive straight in to the folder tree, if you like. I’d suggest easing your way in through the captioned image releases. If you do decide to take the plunge into the archival science data, you might want to read this cautionary tale first.

Learn more about active space missions and their beautiful photos at my blog.