The rock has a diameter of 1.1 to 2.3km and has been named 2022 AP7, discovered between the orbits of Earth and Venus.
The study, written up in the Astronomical Journal and conducted by the Carnegie Institution for Science in Washington, said it was the largest planet killer-sized asteroid seen in eight years.
It was found through the Blanco four-metre telescope in Chile.
2022 AP7 is one of three “rather large” space rocks which could be hazardous, and may even be in the top 5% of the largest ever found, according to the astronomers.
Lead study author Scott Sheppard explained that “any asteroid over 1km in size is considered a planet killer”, because it would cause dust and pollutants to be pushed into the atmosphere.
And they could potentially stay there for a long time, blocking the sunlight and potentially causing a “mass extinction event” which hasn’t been seen on Earth for millions of years, according to Sheppard.
But, while the thought of an asteroid zooming towards Earth may remind people of Adam McKay’s dystopian Don’t Look Up film, there’s a reason astronomers are not sounding the alarm.
It’s not likely to hit the Earth – just the Earth’s orbit. Our planet will be on the other side of the sun during its annual rotation when 2022 AP7 gets close to it, meaning there is no chance of collision any time soon.
Sheppard did warn that it will over time, move closer to the Earth during its orbit, but this will be centuries from now.
He added: “We do not know the orbit of 2022 AP7 precise enough to say much about its dangers centuries from now.”
Only in September, Nasa’s Dart mission to deter an asteroid was successful.
This could become a blueprint of avoiding any collision with Earth, suggesting in the future we will be better protected against such hazards – although 2022 AP7 is probably too big to be stopped in this manner right now with just one Dart.
The director of the National Near Earth Objects Information Centre, Jay Tate, told The Guardian that the Earth was a very small target.
“At the moment, anyway, the impact probability is fairly low. I wouldn’t say negligible, but fairly low,” he said.
