Over a month after Nasa successfully deflected an asteroid in deep space, astronomers have found three new Near-Earth Asteroids (NEAs) and they have been hiding in the inner solar system, making them difficult to find. A 1.5-kilometer-wide object, among the three, has an orbit that may someday place it in Earth’s path.
An international team of researchers used the Dark Energy Camera (DECam) mounted on the VÃctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile to spot these objects. The discovery was tricky since they are in the region interior to the orbits of Earth and Venus, which is a challenging region for observations due to the glare of the Sun.
“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 1 kilometer across, a size that we call planet killers,” Scott S. Sheppard, an astronomer at the Earth and Planets Laboratory of the Carnegie Institution for Science and the lead author of the paper said.
The findings have been published in The Astronomical Journal, which states that the interior asteroid populations are important to complete the census of asteroids near Earth, including some of the most likely Earth impactors that cannot easily be discovered in other surveys.
The team found a trio of near-Earth objects and the 1.5-kilometer-wide asteroid has been named 2022 AP7, which has an orbit that may someday place it in Earth’s path. The other asteroids are 2021 LJ4 and 2021 PH27, which are safely away from Earth’s path.
Astronomers said that 2021 PH27 is the closest known asteroid to the Sun and, as such, it has the largest general-relativity effects of any object in our Solar System and during its orbit, its surface gets hot enough to melt lead.
“There are likely only a few NEAs with similar sizes left to find, and these large undiscovered asteroids likely have orbits that keep them interior to the orbits of Earth and Venus most of the time. Only about 25 asteroids with orbits completely within Earth’s orbit have been discovered to date because of the difficulty of observing near the glare of the Sun,” Sheppard added.
Astronomers maintain that the research is an important step toward understanding the distribution of small bodies in our Solar System. Asteroids that are further from the Sun than Earth are the easiest to detect. Because of that, these more-distant asteroids tend to dominate current theoretical models of the asteroid population. Detecting these objects also allows astronomers to understand how asteroids are transported throughout the inner Solar System.
While astronomers are yet to chart the course of the asteroid and the time period when it could come close to Earth, Nasa has already demonstrated a tool that could be used to deflect it with the successful Dart mission that intentionally crashed into an asteroid to change its orbital speed.