When the eerie skull-shaped Halloween asteroid passed by the Earth on Oct. 31, scientists at NASA didn't hesitate to take images of the space object. Now, further details about the dead comet designated as asteroid 2015 TB145 have been revealed to the public.
The space agency said that the 2,000-foot wide asteroid silently sped by the planet at about 78,000 miles per hour or 35 kilometers per second. The asteroid approached the Earth at about 1.3 lunar distance or 300,000 miles.
Eight individual radar images of the Halloween asteroid were taken by scientists. The images were collected on Oct. 31 between 5:55 a.m. PDT (8:55 a.m. EDT) and 6:08 a.m. PDT (9:08 a.m. EDT). When the radar images were taken, the Halloween asteroid was between 440,000 miles and 430,000 miles apart from the Earth, NASA said.
Lance Benner of NASA's Jet Propulsion Laboratory explained that the new radar images showed parts of the asteroid that have not been previously seen. The images revealed bright spots that could possibly be boulders, pronounced concavities, and other features that could be ridges.
Radar images of the asteroid were first taken by the Arecibo Observatory in Puerto Rico on Oct. 30. Benner said that the new radar images are significantly distinct from the previous ones and are the results of seeing the Halloween asteroid from a different vantage point during its rotation period of three hours.
NASA said that to obtain the new images, scientists in California used a huge Earth-based antenna. The 230-foot DSS-14 antenna transmitted microwaves toward asteroid 2015 TB145. The microwaves rebounded off the asteroid and back to Earth. The National Radio Astronomy Observatory's 330-foot Green Bank Telescope received the radar echoes produced by the contact. When scientists pieced together the image, its resolution was about 13 feet per pixel.
"It is a truly remarkable achievement -- one which we will later be able to apply when future flyby opportunities present themselves," said Shantanu Naidu, a member of the research team.
The asteroid will again pass by the planet in Sept. 2018, in which its distance will be about 24 million miles away from the Earth, scientists said.
Below is the complete radar image of the Halloween asteroid: