The European Space Agency's Hera spacecraft has captured its first image of the double asteroid system Didymos and Dimorphos as separate objects, marking a milestone in its mission to examine the aftermath of NASA's 2022 asteroid impact experiment. Hera was approximately 1,280 kilometers from its targets when it took the image and is expected to unveil its first detailed images of Dimorphos on November 25.
Four years ago, NASA's Double Asteroid Redirection Test spacecraft deliberately crashed into Dimorphos, shortening its orbital period around the larger asteroid Didymos and demonstrating that a spacecraft can change an asteroid's motion. The asteroid's orbital change was substantially greater than computer models predicted, and scientists still do not know whether DART left a crater or significantly altered the asteroid's overall shape. Hera's arrival will help answer those questions.
The October 18 image, taken by Hera's black-and-white Asteroid Framing Camera, shows Dimorphos as around one pixel, clearly separated from Didymos. Michael Kueppers said the asteroid became visible for the first time in this image: “With this image, the smaller Dimorphos asteroid becomes visible for the first time.” He noted that before this acquisition, the spacecraft was still resolving the Didymos system as a single dot.
Mission manager Ian Carnelli said: "For the very first time we are seeing through Hera's own eyes the very double asteroid system that the mission was designed and built for. Our views will grow much sharper as Hera comes closer. We will unveil the first detailed images of Dimorphos -- the first object in the Solar System to have had its orbit measurably shifted by human action -- on 25 November."
Dimorphos is about 151 meters across, comparable to the Great Pyramid of Giza, while Didymos is about 780 meters in diameter, slightly smaller than the Burj Khalifa. The two asteroids orbit each other at an average separation of just 1.15 kilometers. Hera slowed its approach with two thruster firings in October and is now traveling at 20 meters per second relative to the asteroids.
The spacecraft carries a suite of instruments and will release two CubeSats to gather additional data, with plans eventually to include landing operations. The investigation aims to determine the asteroid's composition, internal structure, and mass, so scientists can turn the kinetic impact method into a reliable planetary defense strategy.
For readers interested in following the mission, ESA's Hera Space Companion is an interactive communication platform connected to the mission and designed to make it accessible to the public.
Analysis
Why This Matters
- Hera will provide the first up-close look at a celestial body whose orbit was changed by human action, validating planetary defense techniques.
- Understanding why DART produced an unexpectedly large orbital shift is essential for predicting whether a kinetic impact could successfully deflect a future asteroid threat.
Background
NASA's DART mission on September 26, 2022 was the first test of kinetic impact deflection. The spacecraft struck Dimorphos at about 6.1 km/s, shortening its orbital period around Didymos by about 33 minutes and ejecting debris as far as 10,000 km into space. The European Space Agency's Hera mission was designed to follow up on DART, observing the impact site and measuring the asteroid's properties to improve models for planetary defense.
What to Watch
- November 25, 2026: Hera will release its first detailed images of Dimorphos, revealing possible changes to its shape and surface.
- The deployment of CubeSats and any plans for landing will provide closer measurements, potentially yielding a definitive answer on how the DART collision affected the asteroid.
Checked
12 claims in this story checked against 1 source: 11 supported.
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- SupportedKueppers said, “With this image, the smaller Dimorphos asteroid becomes visible for the first time.”Latest Science News -- ScienceDaily: “"With this image, the smaller Dimorphos asteroid becomes visible for the first time," explains Michael Kueppers.”
- SupportedCarnelli said Hera would unveil the first detailed images of Dimorphos on 25 November.Latest Science News -- ScienceDaily: “"We will unveil the first detailed images of Dimorphos -- the first object in the Solar System to have had its orbit measurably shifted by human action -- on 25 November."”
- SupportedHera captured Didymos and Dimorphos as separate objects for the first time, ahead of its detailed investigation of the impact site.Latest Science News -- ScienceDaily: “For the first time, its onboard camera has captured the two asteroids Didymos and Dimorphos as separate objects rather than a single point of light.”
- SupportedNASA’s 2022 DART mission altered the asteroid system.Latest Science News -- ScienceDaily: “The impact blasted debris as far as 10,000 kilometers into space and shortened the asteroid's orbital period around Didymos by roughly 33 minutes.”
- SupportedHera was approximately 1,280 kilometres from its targets when it took the image.Latest Science News -- ScienceDaily: “Hera obtained the new image on the evening of October 18 using its black-and-white Asteroid Framing Camera, while the spacecraft was approximately 1,280 kilometers from its targets.”
- SupportedHera took the image on October 18 using its black-and-white Asteroid Framing Camera.Latest Science News -- ScienceDaily: “Hera obtained the new image on the evening of October 18 using its black-and-white Asteroid Framing Camera”
- SupportedIn the image, Dimorphos is around one pixel and clearly separated from Didymos.Latest Science News -- ScienceDaily: “even though Dimorphos is made up of only around one pixel in this initial image, it is clearly well separated from its parent body.”
- SupportedHera is expected to unveil its first detailed images of Dimorphos on November 25.Latest Science News -- ScienceDaily: “We will unveil the first detailed images of Dimorphos -- the first object in the Solar System to have had its orbit measurably shifted by human action -- on 25 November.”
- SupportedDART shortened Dimorphos’s orbital period around Didymos.Latest Science News -- ScienceDaily: “The impact blasted debris as far as 10,000 kilometers into space and shortened the asteroid's orbital period around Didymos by roughly 33 minutes.”
- SupportedThe asteroid’s orbital change was substantially greater than computer models predicted.Latest Science News -- ScienceDaily: “The asteroid's orbital change was substantially greater than computer simulations had predicted”
- SupportedScientists still do not know whether DART left a crater on Dimorphos or significantly changed its overall shape.Latest Science News -- ScienceDaily: “Researchers still do not know whether DART left a crater on Dimorphos or significantly altered the asteroid's overall shape.”
- Partly supportedDidymos is about 780 metres in diameter and slightly smaller than the Burj Khalifa.Latest Science News -- ScienceDaily: “Its larger companion, Didymos, is approximately 780 meters in diameter, slightly smaller than the height of Dubai's Burj Khalifa, the world's tallest building.”
