NASA’s DART spacecraft successfully crashes into an asteroid

An illustration of the DART spacecraft heading towards the Didymos binary asteroid system. (NASA/Johns Hopkins Applied Physics Lab, Public Domain/Wikimedia Commons)

On September 26, 2022, NASA’s golf cart-sized Double Asteroid Redirection Test (DART) spacecraft intentionally crashed in the distance asteroid. The spectacular collision, observed by telescopes around the world, was the first practice attempt to alter the trajectory of an asteroid. The $325 million mission was part of the space agency’s overall planetary defense strategy to protect the Earth from the impact of a wandering space rock.

“Were boarding on a new era of humanitya time in which we potentially have the aptitude to protect us from something like a dangerous hazardous asteroid impact. What an incredible thing. We’ve never had this capability before,” said Lori Glaze, director of NASA’s planetary science division.

DART’s target was a small asteroid called Dimorphos. The space rock measures 530 feet (160 meters) in diameter, approximately the size of the Great Pyramid of Giza. It is currently about seven million kilometers from Earth. Dimorphos orbits a larger 2,560-foot (780-meter) asteroid called Didymos.

The asteroid Didymos (top left) and its small moon, Dimorphos, about 2.5 minutes before impact from NASA’s DART spacecraft. (NASA/Johns Hopkins APL)

None of the asteroids is a threatens towards the earth. The binary asteroid system was selected because observe a change of orbit of two space rocks is much easier than that of a single asteroid. Additionally, Didymos has the physical object properties classified by NASA as potentially hazardous asteroids (PHA).

The NASA team will now use ground-based telescopes to determine whether the DART impact changed Dimorphos’ orbit around Didymos. The researchers expect that collision at shorten Dimorphos’ orbit time of about ten minutes.

In October 2024, the European Space Agency (ESA) will launch the Hera mission to perform detailed surveys of the two asteroids. Researchers are particularly interested in learning more about the crater caused by DART collision. They also want to get accurate measurements of the mass of Dimorphos. If successful, Hera will be the first spacecraft to explore a binary asteroid system. He will also be the first to visit a space rock as small as Dimorphos.

Resources: NASA.gov, The Verge.com