The European Space Agency’s Hera spacecraft captured its first close-up view of the Didymos asteroid system from roughly 37 miles away, revealing the previously hidden backside of the primary space rock that NASA’s DART mission never saw before its intentional 2022 collision.
Hera Reveals the Hidden Backside of Didymos
The black-and-white photograph shows the unphotographed hemisphere of the 2,625-foot-wide main asteroid, Didymos. While the image displays the same central ridge along the equator that DART’s earlier views recorded, the rest of the surface differs sharply from previous observations, featuring multiple boulders, craters, and grooves. A tiny sliver of Dimorphos, the 558-foot-wide moonlet that orbits Didymos, appears just below the primary body.
Patrick Michel, Hera principal investigator, described the initial reaction to the telemetry in a statement by saying the perspective felt like observing an entirely new world. Mission scientists attribute some of the newly visible surface characteristics to debris flung across the one-kilometer gap between the two rocks during the kinetic impact.
Comparing the DART Impact Data With New Observations
In September 2022, NASA deliberately crashed the 1,260-pound DART spacecraft into Dimorphos at a speed of about 14,000 miles per hour. Ground-based tracking subsequently confirmed that the impact shortened the moonlet’s orbital period around Didymos from 11 hours and 55 minutes down to 11 hours and 23 minutes.
While space agencies verified that the initial deflection worked, researchers still need comprehensive on-site data to measure the exact momentum transfer, known as the beta factor. Mashable reported that Hera flew for two years to reach the double asteroid system, which currently sits approximately 122 million miles from Earth, to perform this detailed crash scene investigation.
Future Mapping Schedule for the Didymos System
Hera will spend at least six months surveying the binary system to systematically map surface alterations and interior structures using secondary probes like the Juventas companion probe. Michael Kueppers, ESA’s Hera mission scientist, stated that researchers have extensive work ahead to sort out the origins of the surface features.
The European Space Agency’s Hera mission for planetary defence has acquired its first close-up of the Didymos binary asteroid system! 🛰️🪨🪨https://t.co/njlxbN1de4 pic.twitter.com/ESe7mN4Jwq
The European Space Agency scheduled the public release of additional, highly detailed photographs of both Didymos and Dimorphos for November 25.
Frequently Asked Questions About the Hera Asteroid Mission
Why did Hera photograph the backside of Didymos?
NASA’s DART spacecraft approached and impacted Dimorphos from a specific trajectory in 2022, leaving the opposite hemisphere of the larger parent asteroid, Didymos, entirely unphotographed until Hera arrived.
How far is the Hera spacecraft from the asteroids?
The European Space Agency probe captured its initial close-up images from a distance of about 37 miles, while the entire Didymos system sits roughly 122 million miles away from Earth.
When will the European Space Agency release more images?
ESA mission planners scheduled the publication of subsequent, high-resolution photographs of both Didymos and Dimorphos for November 25.
Did the DART impact alter the orbit of Didymos?
No, the DART spacecraft struck only the smaller moonlet, Dimorphos, shortening its orbital period around the primary asteroid Didymos by roughly 33 minutes.