“Our twilight survey is scouring the area within the orbits of Earth and Venus for asteroids. So far we have found two large near-Earth asteroids that are about a kilometer across, a size that we call planet killers,” Scott Sheppard, an astronomer at the Earth & Planets Laboratory of the Carnegie Institution for Science in Washington, DC, said in a media statement.
“The inner asteroids are rare, and deep images are needed because asteroids are faint and you are fighting the bright twilight sky near the Sun as well as the distorting effect of Earth’s atmosphere. The DECam can cover large areas of sky to depths not achievable on smaller telescopes, allowing us to go deeper, cover more sky, and probe the inner Solar System in ways never done before,” Sheppard said.