This image of asteroid 2015 TB145, a dead comet, was generated using radar data collected by the National Science Foundation's 1,000-foot (305-meter) Arecibo Observatory in Puerto Rico. The radar image was taken on Oct. 30, 2015, and the image resolution is 25 feet (7.5 meters) per pixel.
Scientists observing asteroid 2015 TB145 with NASA's Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, have determined that the celestial object is more than likely a dead comet that has shed its volatiles after numerous passes around the Sun.
The belated comet has also been observed by optical and radar observatories around the world, providing even more data, including our first close-up views of its surface. Asteroid 2015 TB145 safely flew by our planet at just under 1.3 lunar distances, or about 302,000 miles (486,000 kilometers), on Halloween (Oct. 31) in 2015.