When we may know if Nasa’s Dart mission successfully deflected asteroid

European Space Agency’s Hera mission would visit the asteroid in 2026 and help better understand Dart’s impact

Over the coming days, weeks, and months, scientists will begin releasing images and data from telescopes and ground-based observations that could reveal the extent to which Nasa’s Dart mission altered the orbit of the asteroid Dimorphos.

Using data from telescopes, such as Webb and Hubble, as well as ground-based observations, researchers are closely monitoring the Dimorphos asteroid onto which Nasa’s Dart spacecraft successfully slammed on Monday.

Nasa’s Dart mission was designed to demonstrate that an asteroid that could potentially cause devastation can be deflected by intentionally crashing a spacecraft into it.

On Monday, at 7.14pm EDT, Nasa made histroy by slamming its Dart spacecraft, travelling at about 6.6 kilometres per second, into the Dimorphos asteroid, about 6.8 million miles from Earth, as part of the first-ever planetary defense mission.

The asteroid Dimorphous — about 160m wide (525ft) — moves around the larger 780m wide (2,560ft) space rock Didymos with an orbital period of about 11.9 hours.

Researchers expect the moonlet would be pushed closer to Didymos following the impact and speed up its orbiting rate around the bigger asteroid.

Nasa scientists expect the Dart mission could cut short Dimorphos’ orbit by about 1 per cent, or roughly 10 minutes.

“It’s like if you damaged your wristwatch and it started running a little bit fast. You might not notice it in the first day or two, but after a few weeks, you will begin to notice that it’s just not keeping the correct time anymore,” Dart programme scientist Tom Statler said in a ESA news webcast earlier this month.

In order to calculate how much the moonlet’s orbit has been altered over time, researchers would measure and track its “light curve” by observing the sunlight reflected from it with telescopes on the ground.

They would use this measure to calculate the change in the orbital period of the double-asteroid system, ESA noted in a statement.

Images from the Hubble and James Webb space telescopes will also help better understand how the Dart collision immediately impacted Dimorphos.

Observations made by Nasa will then be confirmed by its Hera mission that would visit the asteroid Dimorphos in 2026 to view the impact creater left behind by Dart, according to the European Space Agency,

“Hera will then follow-up with a detailed post-impact survey that will turn this grand-scale experiment into a well-understood and repeatable planetary defence technique,” ESA said in a statement.

With the Hera mission, scientists also hope to gather crucial scientific data for future mission planners to better understand asteroid compositions, structures, and behaviours in response to the Dart mission.