NASAさんのインスタグラム写真 - (NASAInstagram)「This crumpled, baked potato-looking space rock is Phobos, one of Mars' two tiny moons. 🥔 Passing time during an internet outage at their UC Berkeley lab, scientists chatted around their coffee pot: Could Mars' moons offer insights into the Red Planet's distant past? After all, Moon rocks returned by Apollo astronauts revealed secrets of Earth's past. It turns out: yes. Digging into the question with help from our MAVEN mission revealed that Phobos, one of Mars' two moons, swims through a stream of particles (oxygen, carbon, nitrogen, argon, and the like) flowing off the Red Planet's atmosphere into space. Many of these charged particles, or ions, have been escaping Mars for billions of years as the planet has been shedding its atmosphere. Some ions, scientists predict, have been smashing into the surface of Phobos and could be preserved in the uppermost "skin" of the compelling space spud that is Phobos. First image: An image of Phobos from March 23, 2008, taken by the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter. Credits: NASA/JPL-Caltech/University of Arizona Second image: Phobos as observed by MAVEN's Imaging Ultraviolet Spectrograph. Orange shows mid-ultraviolet (MUV) sunlight reflected from the surface of Phobos, exposing the moon's irregular shape and many craters. Blue shows far ultraviolet light detected at 121.6 nm, which is scattered off of hydrogen gas in the extended upper atmosphere of Mars. Phobos, observed here at a range of 300km, blocks this light, eclipsing the ultraviolet sky. Credits: CU/LASP and NASA More at the link in our bio! #NASA #Mars #Phobos #SpaceTater」2月2日 4時28分