The European Space Agency's Mars Express probe has been going strong since 2003, and today, it's set to make a new record: it's closest approach to Phobos, the largest moon of Mars. That doesn't say much: depending on who you ask, it's a captured asteroid, a chunk of Mars broken off long ago, or a rubble pile of accumulated debris.
The probe began its encounter at 11 a.m. today, using its sophisticated cameras to detail the surface at unprecedented resolution. Partly, it's a bit of recon work for Russia's fourth attempt at a Phobos lander, set for sometime in the mid 2020s. But with NASA potentially eyeing a crewed Phobos mission, it will be a chance to gain some more insight into the tiny, mysterious world.
Of course, Phobos doesn't geologically have a lot of time left. It's slowly making its way toward Mars, and once it approaches the Roche Limit, tidal forces will rip it apart and give Mars a ring system for a time. But who knows? Maybe our descendants will be there to see it.
