NASA finds 18-meter Falcon-9 crater on the Moon

Six days after the impact, NASA’s Lunar Reconnaissance Orbiter (LRO) flew over the Moon’s northern hemisphere. On August 11 and 12, it photographed the crater left by a Falcon-9 upper stage: about 18 meters wide and nearly 3 meters deep. The orbiter passed the site at an altitude of just under 100 kilometers, traveling at one mile per second, or nearly 5,800 kilometers per hour.

The images show more than just a hole in the ground. Bright and dark streaks surround it. The darker material comes from the upper roughly 45 centimeters of lunar soil, which has been darkened by solar wind, cosmic radiation and micrometeorites. The bright streaks consist of fresh material from deeper layers exposed by the impact.

The image capture was a matter of timing. Ten seconds too early or too late would have shifted the crater 16 kilometers from the center of the image. LRO’s camera can detect features as small as just under one meter from a distance of almost 100 kilometers; to do so, the probe’s orientation had to be adjusted specifically for the task. The first images were provided a few days after the impact by the South Korean probe Danuri.

So what does this change in concrete terms? The images document the crater’s size, depth and exposed soil layers from orbit. The impact on August 5 was expected, but remained invisible from Earth; only a very powerful telescope at the European Southern Observatory in Chile was able to observe it.