Hera mission: Keeping Earth safe from an asteroid collision

The European Space Agency successfully launched its Hera mission on October 7, 2024. Hera is traveling to the asteroid moon Dimorphos to investigate the aftermath of humanity’s first planetary defense test in 2022. It was the first true test of our ability to crash a spacecraft into an asteroid, attempting to deflect it from its path. Watch a reply of the launch above. And below, you can watch EarthSky’s Deborah Byrd speak with Hera project scientist Michael Küppers. Get the latest here about keeping Earth safe from asteroids.

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Hera had a successful launch

The long-awaited Hera mission, which follows the wildly successful DART mission that struck and moved an asteroid in 2022, launched on October 7, 2024. Check out the beautiful selfie Hera took of the spacecraft and Earth as it began its journey to Dimorphos.

View from Falcon 9's second stage during the Hera mission pic.twitter.com/a4Qrgg6Pp6

— SpaceX (@SpaceX) October 7, 2024

When DART his Didymos

Back in 2022, when DART hit Didymos’s little moon Dimorphos, it made a big splash. We know for sure it pushed the asteroid slightly out of its previous orbit. And the debris kicked up in the collision might even have created a new meteor shower for Earth! Hera is going to learn more about just what happened when DART struck the little asteroid, creating a crater on its surface and moving it slightly in orbit. It’s going to learn more about Dimorphos itself, to help refine our knowledge of what DART did … to keep us safe from future asteroid collisions.

On its journey, Hera will first sweep past the planet Mars. It’ll enter Mars’ gravitational field and get a boost in speed, and a slight change in direction, from Mars. After this gravity assist from Mars, Hera should arrive at the asteroid Didymos and its smaller moon Dimorphos in about two years. According to ESA – the mission planner – Hera will conduct a “crime scene investigation” at the little asteroid moon.

Here are 3 mysteries that Hera will help solve

2) Hera will map the crater created by DART’s impact down to 10-cm resolution to help scientists better understand how the surface material responded to the collision. It’s possible that there is no crater at all, rather the impact reshaped the entire asteroid! pic.twitter.com/jmp7K4MXjT

— ESA's Hera mission (@ESA_Hera) September 26, 2024

Hera's investigation of Dimorphos and Didymos will complete the story that DART began two years ago and turn asteroid deflection into a well understood and repeatable technique for protecting Earth from a potential asteroid impact. Stay tuned for launch next month!… pic.twitter.com/L3Wjg16U7m

— ESA's Hera mission (@ESA_Hera) September 26, 2024

Meet the Hera mission

The original plan was for DART and Hera to work as a double spacecraft, but over the years of planning, they became separate missions. Ian Carnelli of ESA’s Hera mission said:

The pair are designed to function separately … their overall science return will be boosted greatly by being able to combine their results.

While scientists closely monitored the 2022 DART impact from Earth, the earthly observations didn’t tell scientists many things about Dimorphos that Hera can learn from close range. So, Hera will inspect the asteroid moonlet to determine its precise mass, what it’s made up of, whether it’s solid or a loose pile of rubble, and what exactly the DART impact crater looks like.

Hera’s contributions

Besides the main spacecraft, Hera will deploy two shoebox-sized satellites. Milani is in charge of spectral surface observations (splitting bounced light from the surface into a rainbow array of colors, then analyzing that light), and Juventas will take the first radar soundings in the heart of an asteroid.

The #HeraMission for asteroid planetary defence will take selfies once in space – here is the approximate field of view of its Spacecraft Monitoring Camera, looking over Hera's instrument-hosting 'Asteroid Deck' https://t.co/VqXqgiRqKV pic.twitter.com/KBJKM6jl3H

— ESA's Hera mission (@ESA_Hera) September 27, 2024

Bottom line: The Hera mission successfully launched on October 7, 2024. Hera will explore Dimorphos, which the DART mission hit as a test of planetary defense in 2022.

Via ESA