European Space Agency's Hera to inspect DART asteroid impact debris

By the year 2019, there were about 19,000 near-Earth asteroids, with the potential of colliding with the planet, observed by NASA. An average of 30 new discoveries are added each week. While some of these asteroids have the potential to destroy minor cities, a lot of them can wipe out Earth entirely.

So what would happen if we ever came face to face with such an apocalyptic scenario?

Just to test that, NASA’s Double Asteroid Redirection Test, most often called DART, was a spacecraft mission launched on September 26, 2022, and was made to deliberately slam into a pyramid-sized asteroid Dimorphos, successfully shortening the asteroid's orbit by 32 minutes, NASA officials announced. While Dimorphos did not pose any threat, the exercise was the first test of Earth's planetary defenses. 

DART was launched on a SpaceX Falcon 9 rocket from California’s Vandenberg Space Force Base. And recently, five new studies concluded that the mission was a resounding success.

Why are we talking about something that happened in September last year?

The European Space Agency will launch a mission next year in October, called Hera, which will return to Dimorphos to inspect the damage done by DART. The mission’s aim is to perform a close-up survey of the aftermath of the collision by DART. It will also measure Dimorphos’ mass and make-up and also of Didymos, the asteroid that Dimorphos orbits around.

Hera is set to land on Dimorphos sometime in late 2026 and will embark on a rendezvous for around six months. And if all goes well, Hera, a car–sized probe outfitted with a large radio antenna and a pair of solar panels, will also try to make a full landing on Didymos.

Hera spacecraft comes equipped with two CubeSats - which are nanosatellites typically weighing between 1 and 10 kg. They will provide significant insights into asteroid science, planetary defenses, and how we can better understand our solar system. 

Hera will thus provide a crucial element in the global effort to avert future asteroid impacts while giving world-leading science.

Patrick Michel, an astronomer at the Côte d’Azur Observatory in France and Hera’s mission principal investigator, told Popular Science, “We want to determine, accurately, how much momentum was transferred to Dimorphos. The problem is that, until humans send an observer to the asteroid, we don’t know what the surface holds in wait for us”.

“A lot of us are wondering how much of the surface we’ll even be able to recognize,” says Andy Cheng, an astronomer at the Johns Hopkins Applied Physics Laboratory who worked on DART.