The James Webb Telescope has identified more than 100 previously unknown asteroids. Scientists will monitor them closely because some are approaching us.
For almost three years, the James Webb Space Telescope has regularly offered new images of space. Astronomers then analyze these and they recently made a surprising discovery. They noted the appearance of never-before-seen asteroids. They counted 138 new ones thanks to the device’s keen detection of thermal emissions from asteroids. Their observations were shared in the journal Nature.
“We expected to detect only a few new objects, but we detected many more than expected, especially the smallest ones,” Julien de Wit, associate professor of planetary sciences at MIT, said in a statement. Astronomers only thought they would discover between 20 and 30. These small asteroids probably came from a series of collisions between several asteroids, thus creating multiple fragments.
These measure between 10 and 100 meters, the size of a bus or a stadium. These so-called “decametric” asteroids were spotted in the main asteroid belt between Mars and Jupiter, located nearly 250 million kilometers from Earth. That doesn’t mean they can’t be dangerous, however. On the contrary, they collide with the Earth 10,000 times more frequently than the largest ones. They are also more difficult to detect.
This study thus made it possible to identify those which are likely to become near-Earthers, i.e. asteroids whose orbit crosses that of the Earth. Six of them appear to be part of it and to be gravitationally pushed on trajectories that will bring them closer to Earth. However, every year on average, a small asteroid falls on Earth, but generally without consequences. In 2013, however, an asteroid measuring around twenty meters exploded above Chelyabinsk in Russia, causing significant damage and thousands of injuries.
“We now have a method to spot these small asteroids at great distances, which is crucial for refining their trajectories and strengthening planetary defense,” said Artem Burdanov, lead author of the study. Furthermore, the next observations from the James Webb telescope will focus on 15 to 20 distant stars, which could lead to the discovery of new decametric asteroids.