Astronomers have detected three asteroids close to Earth, two of which pose as “planet killers” because of their larger and more hazardous sizes. Researchers say the biggest asteroid is the most hazardous object to pose a significant risk to Earth in the last eight years. One of the asteroids, named 2022 AP7, is a little less than one mile wide but has an orbit that could reach Earth’s path in the distant future. The other two asteroids, 2021 LJ4, and 2021 PH27 pose less of a risk of colliding with Earth, researchers say.
According to findings published in the peer-reviewed Astronomical Journal on Monday, the three asteroids, which belong to a group found within the orbits of Earth and Venus, were previously undetectable via telescope due to the glare and brightness of the sun. However, an international team of astronomers waited until twilight at an observatory in Chile to examine the asteroids using a dark energy camera from a Victor M. Blanco 4-meter telescope, according to the National Science Foundation’s NOIRLab.
2022 AP7 orbits the Sun every five years and currently crosses Earth’s orbit when Earth is on the other side of the Sun from it. Eventually, its movement will sync with Earth’s, and they will cross much closer, but this will be centuries into the future. We simply don’t know enough about AP7 in 2022 to precisely predict the danger it may pose centuries from now. At the same time, we suspect there could be other “planet killers” out there yet to be discovered. Right now, there are only about 25 asteroids known to have well-determined orbits that lie entirely within Earth’s orbit. More are likely to be discovered, and these may contribute significantly to the missing 5% of potentially hazardous asteroids.
What makes 2022 AP7 so threatening is the fact that the asteroid won’t burn up in the Earth’s atmosphere because of its large size. 2022 AP7 has a diameter of between 1.1 km and 2.3 km. For context, an asteroid with a diameter of more than 1 km is enough to trigger a mass extinction event on Earth.