European Spacecraft Spots Asteroid Target Separately
Europe’s Hera planetary defense spacecraft has captured its first image showing the binary asteroid system Didymos and Dimorphos as two distinct objects rather than a single point of light. Launched on a SpaceX Falcon 9 rocket in October 2024, the van-sized probe snapped the photo on Oct. 18 from a distance of 795 miles (1,280 kilometers) while sitting approximately 122 million miles (197 million km) from Earth.
“Before this acquisition, the spacecraft was still resolving the Didymos system as a single dot,” Michael Kueppers, Hera project scientist at the European Space Agency (ESA), said in a statement. “But now, even though Dimorphos is made up of only around one pixel in this initial image, it is clearly well separated from its parent body.”
Following NASA’s Historic DART Impact
The mission serves as a follow-up to NASA’s Double Asteroid Redirection Test, which deliberately crashed a spacecraft into the smaller moonlet at 3.8 miles per second (6.1 kilometers per second) in September 2022. That high-speed collision generated a debris plume extending 6,214 miles (10,000 kilometers) into space and slowed Dimorphos’s orbit around Didymos by about 32 to 33 minutes, exceeding the original success threshold of 73 seconds, according to Around Prague.
The larger primary body, Didymos, measures roughly 2,559 feet (780 meters) in diameter, comparable in scale to the Burj Khalifa. Its smaller companion, Dimorphos, spans approximately 495 feet (151 meters) across, roughly matching the size of the Great Pyramid of Giza. Together, the pair orbit the sun while circling one another at an average separation of 1.15 kilometers.
Agency Will Release First Detailed Images on November 25
Mission controllers expect views of the site to sharpen significantly as the probe closes the remaining distance. Ian Carnelli, ESA head of the systems department and Hera mission manager, announced that the agency will release the first detailed images of Dimorphos on November 25, describing the body as the first object in the solar system to have its orbit measurably shifted by human action.
Because the main spacecraft cannot fly extremely close to the surface safely, Hera carries two shoebox-sized CubeSats named Milani and Juventas. Milani will analyze the surface minerals at the impact site, while Juventas deploys ground-penetrating radar to peer about 328 feet (100 meters) beneath the moonlet’s crust.
Frequently Asked Questions About the Hera Mission
Why does Hera need onboard autonomy similar to a self-driving car?
Hera requires advanced onboard autonomy because it must travel safely through a complex orbital environment where two distinct bodies circle one another, as reported by European Space Agency records.
Our Hera spacecraft can now see Didymos and Dimorphos as two separate asteroids! Coming closer, it will study the effects of NASA's 2022 DART impact and help advance asteroid deflection as a planetary defence technique. The first detailed images of Dimorphos are expected on 25… pic.twitter.com/lHA0jU04jT
What specific instruments will map the asteroid surface?
The spacecraft will map Dimorphos using a combination of visual, laser, and radio science instruments alongside data collected by the Milani and Juventas CubeSats.
How far did the debris plume reach after the 2022 collision?
Observations following the DART impact recorded a plume of ejecta rising as far as 6,214 miles (10,000 kilometers) into space.
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