Two weeks before Halloween, researchers observed a fast-moving asteroid approaching Earth closer than anything else has in the past 11 years. Asteroid 2015 TB145 maintained its trajectory and safely passed our planet around 10 a.m. PDT on Halloween at around 1.3 lunar distances, which gave scientists the opportunity to take a series of photos while it flew by.
Using the 70-meter DSS 14 antenna at the Goldstone Deep Space Communications Complex in Fort Irwin, California, the scientists bounced high power microwaves off the asteroid. The echoes were received by another antenna, the NRAO's Green Bank Telescope in West Virginia, which produced high-resolution images with a spatial resolution up to 13 feet per pixel, revealing more information about the speedy rock. "The radar images of asteroid 2015 TB145 show portions of the surface not seen previously and reveal pronounced concavities, bright spots that might be boulders, and other complex features that could be ridges," said Lance Benner, lead on the radar research team and research scientist at NASA's Jet Propulsion Laboratory.
Previous radar images of the asteroid, taken by the National Science Foundation's 1000-foot Arecibo Observatory in Puerto Rico, were at a lower resolution and made the space rock appear more sinister. Some reported seeing a skull in the images, which, while entirely imaginary, was at least appropriately spooky for Halloween.