Hollywood has depicted the apocalypse, with films such as Deep Impact, Armageddon and Don’t Look Up exploring hypothetical scenarios of global destruction by an asteroid colliding with Earth. For those wondering about the fate of an asteroid on a collision course with Earth, NASA already has an answer.
Last year, NASA tested planetary defense for the first time by smashing a spacecraft into an oncoming asteroid to alter its trajectory with the Double Asteroid Redirection Test (DART).
NASA’s Astronomy Picture of the Day is a stunning image of asteroid Dimorphos, captured just 3 seconds before impact. It was a $330 million venture that proved to be a success as the target asteroid named Dimorphos veered off course. Although this asteroid did not threaten Earth in any way, it was an experiment to gain more knowledge about what happens when a ship collides with a space rock. This knowledge will be used if an actual asteroid threatens to crash into Earth.
NASA’s first planetary-defense effort was captured by a small satellite camera that was launched from the DART spacecraft and followed, 3 minutes behind, to the target asteroid Dimorphos.
NASA image description
On the first planetary defense test mission from planet Earth, the DART spacecraft captured this close-up three seconds before the asteroid hit the surface of the moon Dimorphos on September 26, 2022. The outline of the spacecraft with two long solar panels is traced at the projected point of impact between the two boulders. The large boulder is about 6.5 meters across. While the mass of the DART (Double Asteroid Redirection Test) spacecraft was about 570 kilograms, the estimated mass of Dimorphos, the smallest member of a near-Earth binary asteroid system, is about 5 billion kilograms.
The spacecraft’s direct kinetic effects have measurably changed Dimorphos’ speed by a fraction of a percent, reducing its 12-hour orbital period around its larger companion asteroid 65803 Didymos to about 33 minutes. In addition to successfully demonstrating a technique to alter an asteroid’s orbit that could prevent future asteroid strikes on planet Earth, the planetary-scale impact experiment gave the 150-meter-sized Dimorphos a comet-like tail.