The European Space Agency's Hera spacecraft has sent back its first image of the asteroid pair Didymos and Dimorphos, showing the two asteroids as separate objects rather than a single dot. Hera is now about 1,280 kilometres from the pair.
Hera, launched in October 2024, is led by the European Space Agency in cooperation with NASA and Japan's JAXA. It will conduct follow-up observations of NASA's Double Asteroid Redirection Test (DART), which intentionally impacted the smaller asteroid Dimorphos in September 2022 to test whether a collision could deflect an asteroid away from impacting Earth.
The binary system is currently about 197 million kilometres from Earth, with Didymos estimated at 780 metres in diameter and Dimorphos at about 151 metres across.
"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," said Ian Carnelli, ESA head of the systems department and Hera mission manager. "Our views will much grow 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 [2026]."
The DART spacecraft hit Dimorphos at 6.1 km per second, slowing the asteroid's orbit around Didymos by 32 to 33 minutes against an initial target of at least 73 seconds. The mission was deemed a resounding success, with researchers observing an ejecta plume from the surface reaching as far as 10,000 kilometres into space.
Hera will also deploy two shoebox-sized CubeSats, Milani and Juventas, since the main spacecraft cannot fly close to the surface. Milani will perform a close-up mineralogical analysis of the DART impact site, while Juventas will use ground-penetrating radar to look about 100 metres beneath Dimorphos' surface to determine whether its interior is solid rock or the loose rubble pile researchers have proposed.
Planetary defence has become a growing concern among governments, prompted in part by the 2013 Chelyabinsk meteor, which blew out windows and injured more than 1,500 people.
Analysis
Why This Matters
- Hera's observations will show how the DART impact reshaped Dimorphos, the first test of whether a spacecraft collision can reliably deflect an asteroid threatening Earth.
- The mission will reveal whether Dimorphos is solid rock or a loose rubble pile, a factor that would shape how future deflection missions are planned.
- The DART-Hera pairing marks the first full test of kinetic-impact deflection, from the collision itself to close-up study of its aftermath.
Background
In September 2022, NASA's DART spacecraft deliberately crashed into Dimorphos, the smaller member of the Didymos binary system, in the first test of whether an impact could shift an asteroid's orbit. The collision slowed the moonlet's orbit around Didymos by 32 to 33 minutes, far exceeding the minimum target of 73 seconds. Hera, launched in October 2024, is the European follow-up, designed to study the impact site and the asteroid's interior up close.
What to Watch
- 25 November 2026, when ESA plans to release the first detailed images of Dimorphos from Hera.
- The deployment of the Milani and Juventas CubeSats and their first measurements of the impact site.
- Whether Juventas' ground-penetrating radar shows Dimorphos' interior to be solid rock or a rubble pile.
Checked
12 claims in this story checked against 1 source: 11 supported.
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- SupportedHera has returned its first image showing Didymos and Dimorphos as separate asteroids.Universe Today: “Hera recently sent back its first image of Didymos and Dimorphos, which orbit each other as they orbit the Sun, with the image revealing the two asteroids separated, as opposed to seeing a single dot.”
- Partly supportedESA will release the first detailed images of Dimorphos on 25 November 2026.Universe Today: ““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 [2026].””
- SupportedHera is about 1,280 kilometres from the asteroid pair.Universe Today: “Hera ... is now about 1,280 kilometers (795 miles) from the well-known binary asteroid”
- SupportedCarnelli 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.”Universe Today: ““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,” said Ian Carnelli”
- SupportedCarnelli said Hera’s views would grow sharper as it approached and that it would unveil the first detailed images of Dimorphos on 25 November 2026.Universe Today: ““Our views will much grow 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 [2026].””
- SupportedHera launched in October 2024.Universe Today: “This comes after Hera was launched in October 2024”
- SupportedHera is led by ESA in cooperation with NASA and Japan’s JAXA.Universe Today: “a spacecraft mission led by the European Space Agency (ESA) in cooperation with NASA and the Japanese Aerospace Exploration Agency (JAXA).”
- SupportedThe binary system is about 197 million kilometres from Earth.Universe Today: “the latter of which is about 197 million kilometers (122 million miles) from Earth.”
- SupportedThe DART spacecraft hit Dimorphos at 6.1 kilometres per second.Universe Today: “The intentional impact occurred in September 2022 at 6.1 km/s (3.8 mi/s)”
- SupportedThe impact slowed Dimorphos’ orbit around Didymos by 32 to 33 minutes, compared with an initial target of at least 73 seconds.Universe Today: “resulting in not only slowing Dimorphos’ orbit around Didymos by 32 to 33 minutes, with the initial goal being at least 73 seconds.”
- SupportedThe DART mission was deemed a resounding success.Universe Today: “Thus, the mission was deemed a resounding success”
- SupportedThe 2013 Chelyabinsk meteor blew out windows and injured more than 1,500 people.Universe Today: “the 2013 Chelyabinsk meteor that blew out windows and injured more than 1,500 people, primarily from broken glass.”
