An image of the Arecibo Observatory’s iconic radio telescope as seen between two serious cable failures that preceded the facility’s collapse in 2020. (Image credit: University of Central Florida) 

Dead Arecibo telescope offers asteroid warning from beyond the grave | Live Science

The famous Arecibo Observatory in Puerto Rico completely collapsed in 2020. Now, scientists going through its final observations offer a major new asteroid report

After collapsing into pieces in December 2020, the mighty Arecibo Observatory has a final parting gift for humanity — and it’s a doozy.

Using data collected by Arecibo between December 2017 and December 2019, scientists have released the largest radar-based report on near-Earth asteroids ever published. The report, published Sept. 22 in The Planetary Science Journal, includes detailed observations of 191 near-Earth asteroids, including nearly 70 that are deemed “potentially hazardous” — that is, large asteroids with orbits that bring them within 4.65 million miles (7.5 million kilometers) of Earth, or roughly 20 times the average distance between Earth and the moon.

Fortunately, none of these newly described asteroids pose an immediate threat to Earth; according to NASA, our planet is safe from deadly asteroid impacts for at least the next 100 years. However, scientists still pay close attention to near-Earth objects like these in case their trajectories happen to shift by some fluke of nature — say, a bump from another asteroid — thereby putting them on a collision course with Earth.

The new report also flagged several asteroids deemed worthy of future study, including an oddball space object called 2017 YE5 — an ultra-rare “equal mass” binary asteroid, made of two nearly identical size rocks that are constantly orbiting one another. (Each of the rocks is estimated to measure between 2,600 and 2,950 feet, or 800 to 900 meters, in diameter). The asteroid’s high radar reflectivity may indicate an abundance of water ice beneath its surface, possibly making it a never-before-seen class of icy, equal mass, near-Earth asteroid, the researchers wrote.  …