Three near-Earth asteroids have been spotted recently hiding in the glare of the sun, one of which is likely the largest Potentially Hazardous Asteroid (PHA) discovered in the last 8 years, according to research recently published in The Astronomical Journal.
The asteroid in question, dubbed 2022 AP7, was first discovered in January 2022 and determined to be an Apollo type near-Earth asteroid. It is quite large, likely over 1 kilometer in size, and most likely will land in the top five percent of the largest PHAs known.
It has been given the nickname "planet killer" because its potential impact with Earth would result in a mass extinction event the likes of which Earth has not seen in millions of years, according to a recent CNN article. Luckily the asteroid is not on course to hit our planet - it is, however, expected to make a very near pass.
The challenges of asteroid spotting
“Our twilight survey is scouring the area within the orbits of Earth and Venus for asteroids,” said lead study author Scott S. Sheppard, an astronomer at the Earth & Planets Laboratory of the Carnegie Institution for Science in Washington, DC, in a statement to CNN. “So far we have found two large near-Earth asteroids that are about 1 kilometer across, a size that we call planet killers.”
Such a large object on track to pass so close to Earth might normally have been identified earlier; however, its proximity to the sun hid it from vision. "Thus," explain the study authors, "2022 AP7 is a discovery that exemplifies how a relatively large telescope observing toward the Sun during twilight can find large [near-Earth objects] that most of the current NEO surveys do not efficiently find."
"Many of the 'missing' yet-to-be-found ∼1 km sized NEOs likely have orbits that alias with Earth," the study concluded, "making them distant and faint when in the night sky at opposition like 2022 AP7."