Europe's Hera probe sees Didymos and Dimorphos as two separate asteroids for the first time
The ESA probe is closing in on the pair that NASA struck with its DART mission in 2022; the first detailed images of Dimorphos are due at the end of November.
The European space probe Hera has photographed the asteroid Didymos and its small moon Dimorphos as two separate objects for the first time. The image was taken on the evening of 18 October with the black-and-white camera on board, from a distance of around 1,280 kilometres, the European Space Agency ESA reports. The pair is currently about 197 million kilometres from Earth. ScienceDaily highlighted the news again on Tuesday.
Two thruster manoeuvres in October, a week apart, reduced Hera's speed relative to the asteroids to 20 metres per second, ScienceDaily writes, based on ESA material. Dimorphos measures about 151 metres, Didymos about 780 metres. In September 2022 NASA's DART probe slammed into Dimorphos at 6.1 kilometres per second, shortening its orbit around Didymos by roughly 33 minutes, far more than simulations had predicted.
In the coming months Hera is to investigate the impact site: whether a crater formed, how the shape changed and what the asteroid's interior looks like. To do so the probe will also release two shoebox-sized cubesats. ESA expects the first detailed images of Dimorphos on 25 November. The mission should help scientists understand how Earth might one day defend itself against a dangerous asteroid.