As Europe’s Mars Express celebrates 10 years in orbit around the Red Planet it’s getting set to make a daredevil dive on our neighboring world’s largest moon, called Phobos.
Flying past at only 28 miles (45 kilometers) above its craggy surface on December 29, this will be the closest encounter with the potato-shaped moon ever attempted.
“At just 45 km from the surface, our spacecraft is passing almost within touching distance of Phobos,” said Michel Denis, the Mars Express Operations Manager, on the agency’s website.
“We’ve been carrying out manoeuvres every few months to put the spacecraft on track and, together with the ground stations that will be monitoring it on its close approach, we are ready to make some extremely accurate measurements at Phobos.”
Because the flyby speed will be so high, no photos will be possible during this encounter. But European Space Agency (ESA) researchers hope that as the spacecraft swoops in, the gravitational tug of the 17-mile (27 kilometer) wide Phobos will slightly change its speed, helping researchers better understand the moon’s internal makeup.
Previous flybys, including the last one back in March 2010, have shown that Phobos, along with its smaller, more distant sister moon Diemos, are just piles of rubble that are barely held together by gravity. According to hotly contested theories, both Martian moons are most likely captured asteroids, or debris from an ancient impact that was shot into space.
“By making close flybys of Phobos with Mars Express in this way, we can help to put constraints on the origin of these mysterious moons,” said Olivier Witasse, ESA’s Mars Express project scientist.