Arecibo Radio Telescope Captures New Images of ‘Potentially Hazardous Asteroid’ 3200 Phaethon

Updated | When Hurricane Marie swept through Puerto Rico, it left behind extensive damage to many structures, including the Arecibo Observatory Planetary Radar—the world’s second-largest single-dish radio telescope. Although the telescope's radio activity resumed in a matter of days, its ability to collect radio observations was halted for months. More than three months later, the telescope is finally back up and running as usual.

3200 Phaethon—an Apollo asteroid—came the closest to Earth it has ever been on December 16. On that date, the telescope captured high-quality images of the asteroid, which won't be in such close proximity to Earth until the year 2093, according to Space.com. The new radar images show off the asteroid’s immense size, shape, as well a, a notable dark feature near one of its poles.

“These new observations of Phaethon show it may be similar in shape to asteroid Bennu, the target of NASA's OSIRIS-REx spacecraft, but more than 1,000 Bennus could fit inside of Phaethon,” Patrick Taylor, a Universities Space Research Association (USRA) scientist and group leader for Planetary Radar at Arecibo Observatory, said in a statement. “The dark feature could be a crater or some other topographic depression that did not reflect the radar beam back to Earth.”

Images also reveal Phaethon is larger than astronomers previously thought, measuring about 3.6 miles wide. Despite being classified as a “potentially hazardous object,” it’s unlikely that Phaethon will come into contact with Earth.

“Any body that's bigger than about 500 feet across and its orbit carries it within about 4.6 million miles of Earth at any point in its orbit is classified as a 'potentially hazardous' object,” Bill Harwood, a CBS News space consultant, explained to the news outlet. “Meaning over millennia — lots and lots of time — gravitational interactions with the outer planets, you know, other objects in the solar system might perturb the orbit enough that it could actually impact the Earth.”

12_24_Arecibo Observatory The Arecibo Observatory is seen after it was hit by Hurricane Maria on September 29, 2017 in Arecibo, Puerto Rico. Puerto Rico experienced widespread damage including most of the electrical, gas and water grid as well as agriculture after Hurricane Maria, a category 4 hurricane, passed through. Joe Raedle/Getty Images

It’s unknown exactly where the massive object came from, but one theory suggests it used to be a comet; however, it’s true origin has perplexed astronomers. In 1983, Pantheon became the first-ever asteroid to be discovered via satellite. For decades, the NASA-funded Arecibo Observatory has provided important images of both Pantheon and various other types of data to scientists.

“Arecibo is an important global asset, crucial for planetary defense work because of its unique capabilities,”Joan Schmelz, USRA Director and Deputy Director of Arecibo Observatory, said in a statement.

This article has been updated to include new information from NASA.