The Halloween asteroid that zoomed past Earth yesterday is most probably a dead comet that resembles a skull, astronomers at NASA have revealed.
Astronomers have been observing the asteroid 2015 TB145 aka the Halloween Asteroid ever since it was discovered on October 10 and scientists observing it with NASA’s Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, have suggested that the asteroid is more than likely a dead comet that has shed its volatiles after numerous passes around the sun. The data collected by the IRTF has helped put to rest the debate over whether 2015 TB145 is an asteroid or is of cometary origin.
Radar images of the asteroid have also been generated using National Science Foundation’s 305-meter (1,000-foot) Arecibo Observatory in Puerto Rico and according to the images, the asteroid is spherical in shape and approximately 2,000 feet (600 meters) in diameter and completes a rotation about once every five hours.
“The IRTF data may indicate that the object might be a dead comet, but in the Arecibo images it appears to have donned a skull costume for its Halloween flyby,” said Kelly Fast, IRTF program scientist at NASA Headquarters and acting program manager for NASA’s NEO Observations Program.
“We found that the object reflects about six percent of the light it receives from the sun,” said Vishnu Reddy, a research scientist at the Planetary Science Institute, Tucson, Arizona. “That is similar to fresh asphalt, and while here on Earth we think that is pretty dark, it is brighter than a typical comet which reflects only 3 to 5 percent of the light. That suggests it could be cometary in origin –- but as there is no coma evident, the conclusion is it is a dead comet.”
Radar images generated by the Arecibo team are available at: https://www.facebook.com/notes/national-astronomy-and-ionosphere-center-arecibo-observatory/near-earth-asteroid-2015-tb145-passes-by-without-a-fright/1082765941733673
Asteroid 2015 TB145 has already cruised past Earth on the night of October 31 and the next time it will be visiting Earth is September 2018, when it will make a distant pass at about 24 million miles (38 million kilometers), or about a quarter the distance between Earth and the sun.