Hera Mission Flyby Data Informs New Study on Deimos's Formation
A new study, informed by flyby images from the European Space Agency’s (ESA) Hera asteroid mission, suggests that Mars’s outer moon Deimos was significantly reshaped by a single, violent asteroid impact. This impact is believed to be responsible for Deimos's unusually smooth and youthful appearance, attributed to a thick layer of dust, or regolith, that covered its surface after the collision. The study, published in Nature Astronomy, utilized high-resolution impact simulation software to recreate the event. Researchers, led by Sabina Raducan of the University of Bern, International Space Science Institute (ISSI), and VUB Brussels University, ran approximately one hundred simulations. Their findings indicate that a slanting, 45-degree impact from a relatively small 320-meter-wide asteroid, striking at high speed, excavated a broad depression at Deimos's south pole and dispersed a large amount of material across its surface. Much of this debris subsequently fell back, forming a global blanket of loose regol... 
