Astronomers have discovered a giant asteroid hiding in the sun’s glare that could one day cross paths with Earth
0.9 miles (1.5 kilometers) wide asteroid is the largest potentially dangerous asteroid seen in eight years, and astronomers have dubbed it a “planet killer” because the effects of its impact will be felt across many continents.
The asteroid, called 2022 AP7, has gone unnoticed for so long because it orbits in the region between Earth and Venus. To spot space rocks in this area, astronomers must look in the direction the sun, and this is notoriously difficult due to the brightness of the sun. For example, flagship telescopes such as James Webb Space Telescope and Hubble Space Telescope never look at the sun like a starThe brightness roasts their sensitive optics.
Because of this, astronomers have only a limited understanding of the nature of the asteroids that lurk in this region, and surprises can sometimes happen. In 2013, a much smaller asteroid, just 66 feet across (20 m), flew in from the direction of the sun completely without warning. This asteroid exploded over the city Chelyabinsk in the south-east of Russia, breaking windows in thousands of buildings.
“To date, only about 25 asteroids have been identified with orbits that lie entirely within Earth’s orbit, due to the difficulty of observing near the sun’s glare,” said Scott S. Sheppard, an astronomer at the Carnegie Institution for Science’s Earth and Planetary Laboratory and lead author. of the article describing the new discovery, said in a statement (opens in a new tab).
The discovery of 2022 AP7, which would be far more damaging than Chelyabinsk if it collided with Earth, was only possible thanks to the Ultra-Sensitive Dark Energy Camera (DEC) at the Cerro Talolo Inter-American Observatory in Chile, which scans the sky during twilight, when these asteroids can be seen. detect for two 10-minute periods each day.
“So far we have found two large near-Earth asteroids about 1 kilometer in size [0.6 miles] a size we call planet killers,” Sheppard said.
Because inner solar system asteroids are very difficult to detect, they are underrepresented in models of the general system Solar system space rock population. However, Sheppard believes there are only a few unknown “planet killers” left in this hard-to-observe region. The good news is that most of these unknown asteroids are likely in orbits that keep them safely away from Earth.
“Most likely, there are several of them [Near Earth Asteroids] with the same sizes that remain to be found, and these large undiscovered asteroids probably have orbits that keep them inside the orbits of Earth and Venus most of the time,” Sheppard said.
In addition to the potentially threatening 2022 AP7, astronomers discovered two other smaller space rocks during the DEC observations, one of which is the closest to the Sun ever seen. Because of its proximity to a star at the center of the Solar System, this asteroid, named 2021 PH27, is the most affected by general relativity of any object in the Solar System, scientists said in a statement.
In accordance with Albert Einstein’s General Theory of Relativity, massive objects warp space-time, which can affect the motion of other nearby objects. These effects, which are very small, can be observed as disturbances in the orbits of planets and asteroids that cannot be explained Newtonian physics. Fortunately, both 2021 PH27 and a third asteroid, called 2021 LJ4, are in orbits that do not intersect with Earth’s orbits.
Astronomers are currently observing more than 2,200 potentially hazardous asteroids, space rocks that orbit very close to Earth and are more than 0.6 miles across [1 km]. Such asteroids are of greatest concern because they cause widespread destruction that can affect the entire planet. However, even much smaller asteroids would cause a lot of problems if they fell into densely populated areas. For example, an asteroid just 160 feet (50 m) wide would damage all of London if it exploded over the city center.
Fortunately, astronomers can calculate the trajectories of asteroids centuries into the future, and there are currently no known space rocks that should worry us. And by the time such a stone appears, the global space community hopes to have the tools in hand to protect the planet. In September NASA’s Dual Asteroid Redirection Test (DART) the mission successfully altered the trajectory of the 525-foot-wide (160 m) asteroid moon Dimorphos, which is orbiting its 2,560-foot-wide (780 m) host rock Didymos. The success of this first-of-its-kind experiment suggests that as long as we know about it early enough, we can keep pesky asteroids at bay.