Hera's First Close-Up of Didymos Shows the Asteroid DART Never Saw

For nearly four years, the most famous asteroid collision in history had only one eyewitness up close: a tiny Italian CubeSat that zipped past for a few minutes and then was gone. That changed on 5 November 2026. The European Space Agency released the first close-up picture from its Hera spacecraft, and the view of Didymos is not what anyone expected. The Hera spacecraft Didymos image shows a battered, boulder-strewn world, and it is the side of the asteroid that NASA's DART probe never got to see before it crashed.

If you follow our coverage of asteroids passing Earth today, you already know that most space rocks stay as faint dots in a telescope. Seeing one in this much detail is rare. Here is what the new picture shows, why scientists are excited about it, and what happens next.

What the first Hera close-up actually shows

The image was taken with Hera's Asteroid Framing Camera, a black-and-white navigation and science camera, from roughly 60 kilometres away. At that distance the main asteroid, Didymos, fills most of the frame. It is about 780 metres wide, which is a bit more than twice the height of the Eiffel Tower. Its little moon, Dimorphos, is only about 151 metres across and sits mostly in shadow, so in this first frame you only catch a thin sliver of it.

The surprise is the surface of Didymos itself. The asteroid still has the raised ridge around its equator that DART's camera spotted in 2022, which gives it a spinning-top look. Apart from that, this face looks quite different. It is covered in boulders, it has craters, and there are long lines that look like grooves or ridges crossing the ground. According to ESA's Hera mission team, the reaction in the control room was simple: the first thing they said was "wow". Principal investigator Patrick Michel described it as looking at a whole new world, because DART only ever photographed the opposite side.

Some team members have suggested that part of the rubble on Didymos may have come from Dimorphos. When DART hit the moon, it threw out a huge cloud of rock and dust. If some of that material drifted down onto the bigger asteroid, it would have changed the surface there too. Hera's job is to find out whether that really happened.

A quick reminder: what did DART do in 2022?

On 26 September 2022, NASA's Double Asteroid Redirection Test (DART) flew deliberately into Dimorphos. The spacecraft weighed about 580 kg and was travelling at roughly 6 kilometres per second. Before the impact, Dimorphos took about 11 hours and 55 minutes to circle Didymos. Afterwards, the orbit was about 33 minutes shorter, give or take a minute.

That is a much larger change than many models predicted. The reason seems to be the material blasted off the surface. As it flew away, the ejecta pushed back on Dimorphos like the exhaust of a small rocket, adding extra shove on top of the impact itself. This was the first time humans had measurably changed the path of a natural object in the Solar System, and it was a proof of concept for planetary defence. Neither asteroid was ever a danger to Earth, which is exactly why they were chosen for the test.

The problem is that ground-based telescopes could only measure the orbit change. They could not tell scientists how big the crater is, how much mass Dimorphos has, or whether the moon was reshaped. Without those numbers, it is hard to know how well the same trick would work on a different asteroid. That is where Hera comes in.

How Hera got here

Hera launched on 7 October 2024 on a SpaceX Falcon 9 rocket. Exactly two years later, on 7 October 2026, it caught its first faint glimpse of the Didymos system from about 236,500 km away, which is a little closer than the Moon is to Earth. A series of braking burns in October slowed the spacecraft down so it would not simply fly past.

On 18 October, from around 1,280 km, the camera managed to split the pair into two separate objects for the first time. In that picture Dimorphos was barely more than a single pixel, but it was clearly apart from its parent. ESA shared that "first light" image on 27 October. Then, less than two weeks later, came the 60-km close-up. In about a month, the target went from a dot to a landscape you can actually study.

What Hera will measure next

Think of Hera as a crash-scene investigator. Its main task is to map Dimorphos in detail and answer the questions DART left open. The team wants to know:

• The crater: how wide and deep DART's impact scar is, or whether the moon was reshaped so much that there is no neat crater at all.
• The mass: how heavy Dimorphos is. This is the key number for working out how efficient the push really was.
• The interior: whether the moon is a loose pile of rubble held together by weak gravity or something more solid.
• Changes to Didymos: whether debris from the impact landed on the larger asteroid and altered its surface or spin.

To help, Hera carries two shoebox-sized CubeSats called Milani and Juventas. Milani will study the dust and minerals around the asteroids, and Juventas carries a low-frequency radar to look inside Dimorphos. That radar may be the first ever to see the inside of an asteroid. The full investigation is planned to last at least six months.

The next big date is 25 November 2026, when ESA has said it will release detailed images of both asteroids. We will add it to our upcoming space events list so you don't miss it.

Why this matters for life on Earth

It is easy to file asteroid deflection under science fiction, but the logic is very practical. If astronomers ever find a rock on a collision course with Earth, the best plan is to nudge it years in advance. A tiny change in speed, applied early enough, adds up to a miss of thousands of kilometres. DART proved that a spacecraft can deliver that nudge. Hera will tell engineers how big a spacecraft they would need, and how much warning time is enough, for a real threat.

Without Hera's measurements, DART is a single successful experiment with a lot of unknowns. With them, it becomes a tested method with real numbers behind it. That is the difference between hoping a technique will work and knowing it will.

Can you see Didymos from Earth?

Not with ordinary equipment. Didymos is far too small and faint for backyard telescopes at the moment, and Dimorphos is even harder. The good news is that you can follow the mission online, and you can still enjoy the night sky while you wait. Mars and Jupiter will sit close together before sunrise in mid-November. Our planets visible tonight page shows where to look from your own city.

The bottom line

The first close-up from the Hera spacecraft is only the opening chapter. One picture has already shown that Didymos is rougher and more interesting than scientists thought, and the side DART never saw looks like a new world. Over the coming weeks the images will get sharper, and by the end of the month we should finally see the scar left on Dimorphos. You can follow every update on ESA's Hera mission page. We will report the 25 November images here as soon as they are out.