NASA scientists carefully move the DART spacecraft during construction.
On November 24, 2021, the National Aeronautics and Space Administration (NASA) launched a spacecraft at an asteroid more than 6 million miles away. It may sound like the plot of a disaster movie. But, you can rest assured that Earth is not in any immediate danger of being hit by an asteroid. At least, not one large enough to end all life on the planet.
Part of NASA’s mission is planetary defense. In this role, NASA monitors near-Earth objects (NEOs). NEOs are asteroids, comets, and other space objects that orbit our Sun. These objects are considered near-Earth because they are within 30 million miles of Earth’s orbit. Currently, there are more than 20,000 NEOs.
What if one of these objects were to drift into Earth’s orbit? How might we defend our planet? These are the questions NASA hopes to help answer with the DART mission. DART stands for Double Asteroid Redirection Test. NASA will have to wait a while to get the results from the DART mission, though. The DART spacecraft will not reach the target asteroid until September 2022.
This asteroid is more than 160 meters wide (more than 500 feet). The golf-cart-sized DART spacecraft will be traveling at more than 15,000 miles an hour. The collision between the two should knock the asteroid slightly off course. If successful, this would be enough of a course change to divert the asteroid from impacting Earth. That is, if the asteroid were headed toward Earth (it is not).
About 10-days before impact the spacecraft will launch a small satellite. This satellite will record and send images of the collision back to Earth. In 2024 a follow-up mission is planned by the European Space Agency. This mission will photograph the crater created by the impact of the DART spacecraft. NASA hopes that all of this data will help direct future efforts at deflecting asteroids. Deflection is just one of the tools in NASA’s planetary defense toolbox.