When the DART spacecraft intentionally struck an asteroid, to attempt to nudge it from its path, it additionally launched a swarm of boulders.
DART asteroid affect had unwelcome penalties
The DART spacecraft’s deliberate affect with tiny asteroid moon Dimorphos – in September 2022 – was an train in planetary protection. Area scientists wished to know if we might defend Earth towards an asteroid on a collision course by knocking it off target. It was solely a take a look at. However the technique labored. The spacecraft affect did nudge the asteroid, a bit. However, based on UCLA astronomer Dave Jewitt and his staff, the affect had unexpected penalties.
A Hubble Area Telescope picture of Dimorphos – captured in December 2022 – clearly reveals a particles area of boulders blown from the asteroid’s floor. And, as Jewitt stated in a press release in early August 2023:
The boulder swarm is sort of a cloud of shrapnel increasing from a hand grenade. As a result of these large boulders mainly share the velocity of the focused asteroid, they’re able to doing their very own injury.
The peer-reviewed Astrophysical Journal Letters published Jewitt and staff’s leads to July, 2023.
Are these boulders a hazard to Earth?
No. The DART mission befell over 6 million miles (about 10 million km) away. That’s greater than 20 instances the moon’s distance. So the boulders blown off the asteroid by the spacecraft aren’t close to us in space. They’re no risk to us.
Nonetheless, Jewitt’s outcomes are meals for thought. In any case, as Jewitt additional defined:
… given the excessive velocity of a typical affect, a 15-foot boulder hitting Earth would ship as a lot power because the atomic bomb that was dropped on Hiroshima.
Defending Earth was the aim of the DART mission. However Jewitt’s research discovered that 37 boulders flew from Dimorphos’ floor, into space, following the DART affect. The boulders vary in dimension from 3 to 22 toes (1 to six.7 meters). They’re, basically, new asteroids, and as such they’re probably able to putting Earth.
However, once more, these explicit boulders flung into space are not any risk to Earth. In the event that they had been, Jewitt stated:
They’d hit on the identical velocity the asteroid was touring — quick sufficient to trigger large injury.
What DART did
The asteroid Dimorphos is tiny. It’s solely about 581 toes (177 meters) in diameter. It grew to become the designated goal for the DART mission partly for that motive, and in addition because of its relative nearness to Earth.
DART stands for Double Asteroid Redirection Check. The DART spacecraft weighs in at a half-ton. So, scientists believed that smashing the spacecraft into the asteroid may change Dimorphos’ trajectory.
On September 26, 2022, DART crashed into Dimorphos at 13,000 mph (21,000 km/h). NASA confirmed that it lowered the orbit of Dimorphos round its companion asteroid Didymos by just a few millimeters per second.

Boulders had been on Dimorphos’ floor
Jewitt’s research decided the boulders in all probability flew off Dimorphos’ floor through the affect by DART.
Shut-up pictures from DART shortly earlier than affect indicated the floor had equally sized rocks on its floor.
And, by the way in which – within the picture on the prime of this publish – these small boulders captured by the Hubble Telescope are a number of the faintest objects ever imaged in our solar system. Jewitt stated:
If we comply with the boulders in future Hubble observations, we would have sufficient knowledge to pin down the boulders’ exact trajectories.
After which we’ll see through which instructions they had been launched from the floor and determine precisely how they had been ejected.
HERA will research Dimorphos, too
The European Area Company’s HERA spacecraft will go Dimorphos in December 2026. It’ll collect more data on the aftermath of the affect, together with the boulders ejected from the asteroid. In any case, the boulders will nonetheless be there then, touring with Dimorphos in orbit across the sun.
And so HERA’s knowledge are anticipated to assist form future methods for planetary protection.

Backside line: In accordance with a current research from UCLA, intentionally altering the course of an asteroid heading had surprising penalties.
Watch DART asteroid impact in Hubble movie
Source: The Dimorphos Boulder Swarm