Planet-killer asteroid will reach Earth’s orbit

An asteroid over the UK, that fortunately avoided hitting us  (Jill Hemingway/PA)
An asteroid over the UK, that fortunately avoided hitting us (Jill Hemingway/PA)

A large asteroid dubbed a “planet killer” has been discovered by scientists.

According to astronomers, the planet-killer-sized asteroid 2022 AP7 will cross Earth’s orbit. However, fortunately, this will be in the distant future.

It had been hidden behind the glare of the Sun, according to a press release from NOIRLab.

Based on the new study published in the Astronomical Journal, the asteroid is likely the largest Potentially Hazardous Asteroid discovered in the past eight years.

It is also one of three near-Earth asteroids that were found orbiting between Earth and Venus - the other two have been named 2021 LJ4 and 2021 PH27, with the latter being the closest known asteroid to the Sun. According to the study, its surface is hot enough to melt lead while it is in orbit.

The lead author of the study and astronomer Scott S Sheppard said: “Our twilight survey is scouring the area within the orbits of Earth and Venus for asteroids.

“So far, we have found two large near-Earth asteroids that are about one kilometre across, a size that we call planet killers.”

He added, “If this one hits the Earth, it would cause planetwide destruction. It would be very bad for life as we know it.”

However, astronomers have predicted that humanity is probably safe for a “few thousand years”.

It’s not all good news, however. The discovery suggests there could be other ‘planet killers’ lying undiscovered in the solar system.

Given that astronomers can only study the inner solar system during two 10-minute periods each night to avoid being blinded by the Sun's powerful glare, finding space rocks pose a significant observational challenge.

There are less than 1,000 potentially dangerous asteroids, of which it is thought that we have already detected around 95 per cent of them.

Because of observational blind areas and the fact that we can't constantly study the entire sky, we haven't yet discovered every item that might one day pass close to Earth.

It is challenging to make observations near the Sun. Small asteroids’ weak light reflections are obscured by the Sun's brightness, creating a blind spot. However, there is a brief period right before and after sunset during which the Sun's glare does not obscure the view.

Right now, there are only about 25 asteroids known to have well-determined orbits that lie entirely within Earth’s orbit.