Although for many decades the planet Mars has been poked, prodded, driven, flown over and especially circled by various spacecraft, landers and rovers sent over by a certain humanoid species on Earth, the two moons orbiting Mars have featured significantly more in science fiction and video games than in scientific literature. This is now about to change when the Martian Moons eXploration (MMX) mission launches on October 19, which will include a sample return from Phobos.
Until now, these two moons of Mars – Phobos and Deimos – have received only a few cursory glimpses by passing spacecraft, leaving many fundamental questions surrounding their formation and composition wide open. That was to change dramatically with the MMX mission, with this spacecraft intended to take detailed measurements of both moons.
In addition, a rover – called Idefix – will make a landing on Phobos for observations of its surface. This will be quite a feat, because despite this lander coming in at 25 kg, on the surface of Phobos it will weigh only 15 grams due to the low gravity, or even less than the diminutive canine companion of Obelix, with potential beans as we have seen with previous landing attempts on such small bodies.
After launch, the MMX mission will take a year to arrive at Mars, in August of 2027, with Idefix released in early 2029 for its hopefully soft paws down on the surface of Phobos where it can shake for a while until the main MMX spacecraft later withdraws for its sample and returns part of the mission. If all goes well, this would mean that a sample of Phobos should land in Australia in 2031.