A spacecraft from NASA called DART will soon purposely crash into an asteroid called Dimorphos to test a new defense method against asteroids. While this asteroid itself is not dangerous, anything new learned from this experiment would help significantly if an asteroid actually threatens the earth.

NASA monitors about 28,000 nearby asteroids, even though they are far away from the earth. About 3,000 new asteroids are discovered every year, so it’s possible that one will eventually have a trajectory toward the earth. NASA is doing this experiment to find a way to change the trajectory away from the earth, Dimorphos also decided to test it since it is similar to other binary pairs scattered in the solar system. While the earth is not at risk of being hit by any big asteroid for at least 100 years, the main concern is about a potential NEO (Near Earth Object) that suddenly comes from space with no warnings.

DART first launched into space on a SpaceX Falcon 9 on November 24, 2021. The spacecraft is almost finished with its 11-month journey, traveling about 11 million kilometers.

In the final 3 weeks of the journey, there will be 3-course corrections that are required to keep DART on track. The last one will happen about 24 hours before the impact, and at that point, the navigation team will know the position of Dimorphos to an accuracy of 2 kilometers. From this point, SMART NAV, DART’s autonomous navigation system, will steer toward the target. Dimorphous orbits another slightly bigger asteroid called Didymos, but SMART NAV was designed to differentiate the 780-meter-wide Didymos from the 160-meter-wide Dimorphous.

Finally, on September 26, the 624-kilogram spacecraft will smash into Dimorphos at about 24,000 kilometers per hour. If the trajectory of Dimorphos is successfully altered, then NASA will have discovered a viable method for stopping dangerous asteroids from hitting the earth.

NASA gave the 4 primary objectives of this experiment: to change the orbital trajectory, to demonstrate a kinetic impact, to measure changes in Dimorphos’s orbital period, and to measure the physical effects of the impact.

DART is NASA’s first defense mission, although it is built and designed by Johns Hopkins Applied Physics Laboratory. NASA’s Planetary Defense Coordination Office assigned them the job of managing this project. Still, other significant contributors include the Jet Propulsion Laboratory, the Italian Space Agency, NASA Goddard Space Flight Center, the European Space Agency, Johnson Space Center, and many others.

If you want to watch the impact live, NASA will begin a live stream on September 26 at 6:00 PM (EDT) and the impact is expected to happen exactly at 7:14 PM (EDT). The live stream will be available on NASA TV, NASA YouTube, NASA Twitter, and NASA Facebook.