Today the camera eyes of the European Space Agency’s Mars Express spacecraft will scrutinize the oddly shaped and pockmarked Phobos, as it makes its closest ever pass by the largest of Martian moons, gliding a mere 60 miles above its surface.
The spacecraft will use all of its high-tech tricks to perform a thorough examination, taking 3-D images, mapping with a high-resolution camera, making precise measurements of the Phobos’ mass and composition, and unleashing its subsurface probing radar to study the the moon’s insides. But Mars Express isn’t done yet. It will travel again pass Phobos two more times this summer, collecting a wealth of new data.
Researchers are interested in Phobos because it is seen as a feasible compromise between sending astronauts to the moon, an extremely difficult but already accomplished feat, and sending astronauts to Mars, in what is likely to be a very dangerous, long, and tedious mission.
But that doesn’t mean that Phobos is the back-up guy, the stand-in for space exploration. Aside from a considerably less risky mission, Phobos may be more interesting than previously thought. Some Scientists believe the moon might be harboring ice underneath its cratered surface. Plus, the origins of Phobos (along with Deimos- the other Martian moon) still aren’t clear.
It is unknown if the moons were created at the same time as Mars, or if they are asteroids that wandered into Martian orbit later, in which case Phobo’s exploration would be especially fruitful. Asteroids are known for having have lots of rich metals like metallic iron and nickel.