File:Asteroid Didymos before the DART impact (potw2239a).tiff

English: The arrow in this Picture of the Week marks the asteroid Didymos as seen on the night of September 25/26 with ESO’s Very Large Telescope (VLT) in Chile. Didymos has a smaller 160-metre-long moon called Dimorphos (not seen here), and on 26 September at 23:14 UTC a NASA probe is set to crash into this moon as part of the Double Asteroid Redirection Test (DART). Our VLT, like many other telescopes around the world, will be watching.The purpose of the mission is to see if a future potentially dangerous asteroid could be deflected from its trajectory using this method. The material following the crash will also hopefully provide us with more information about the composition of asteroids – the original building blocks of our planet.At ESO’s Paranal Observatory in Chile, all four 8.2-metre telescopes of the VLT will observe the aftermath of the impact with different instruments. The resulting data will allow astronomers to study the composition and motion of the ejected material, the structure of the asteroid’s surface and its internal properties.The results of this experiment may provide a method of protecting our planet from hazardous asteroids but will also deepen our understanding of asteroids and hence the formation of our Solar System. To learn more about the important scientific data that will be obtained by the VLT, read our latest blog post.