Twenty-first century science fiction films have come up with many ideas to divert an asteroid from its original flight path. However, so that the experiments did not remain only on the screen, NASA decided to test one of these directly in space. It purposefully sent a spacecraft toward the asteroid, and according to the results it released this week, the test was a success.
During the experiment, the lunar asteroid Dimorphos was successfully deflected into the orbit of another asteroid called Didymos. This resulted in a slight deviation of this pair to a different orbit of the Sun than the one it was originally supposed to travel along.
The scientists also obtained the most accurate results possible thanks to astronomers from all over the world who voluntarily helped them in measuring so-called star eclipses. These are situations in which the observed object (in this case an asteroid) flies in front of the star from a human perspective.
In this phenomenon, according to Makadia, the observed object is darkened for about a second by the light from the star, which allows researchers to very precisely measure the position, shape and speed at which it moves through space. Astronomers managed to capture twenty-two of these eclipses over several years.
“The change in orbital velocity of the two-asteroid system was about 1.7 inches (4.3 centimeters) per hour. Over time, this can make a big difference to the asteroid’s motion in whether or not a hazardous object hits our planet,” Makadia described in a NASA statement.
Thomas Statler, NASA’s lead researcher for small solar system bodies, also sees the study as essential. “It’s a small change in circulation, but given enough time, even a small intervention like this can grow into a major deviation,” Statler said.
According to him, the scientific team worked precisely and proved that the kinetic impact can be used as a technique to defend the Earth against dangerous asteroids. Statler also considers it crucial that only one of the asteroids needs to be hit to deflect the pair.
The entire research is part of the DART (Double Asteroid Redirection Test) mission, which NASA started already in 2022. The American space organization is also preparing other projects for the purpose of defending the Earth. For example, he is preparing a telescope that will be able to detect even the most difficult-to-see objects, such as dark asteroids and comets.
