NASA announced today that its DART mission was completely successful. Not only was its probe able to knock a massive asteroid off course, but it also shortened its orbit by over 25 times more than the defined minimum.
During a press conference, agency administrator Bill Nelson shared that the orbit of a 520ft space rock called Dimophoros changed course as expected when a refrigerator-sized craft crashed into it at a speed of 14,000 mph on Sept 26.
NASA launched the probe with help from the Johns Hopkins University Applied Physics Laboratory to test methods of protecting Earth from possible asteroid impacts in the future. And the results prove that it could possibly defend the planet if the administration has adequate warning time, and the target is not much larger than Dimophoros.
“This mission shows that Nasa is trying to be ready for whatever the Universe throws at us,” said Nelson. “I believe that Nasa has proven that we are serious as a defender of the planet.”
When the probe collided with the asteroid some 7 million miles from Earth last month, scientists immediately knew that it had affected the orbit. But team members had to run a series of calculations to know if the orbit shortened.
Dimorphos circles around a larger rock named Didymos. Before impact, it took the asteroid 11 hours and 55 to complete one circuit. On Tuesday, Nelson shared that the impact decreased that time by 32 minutes. That happened because Dimorphos moved closer to Dimorphos by “tens of meters.”
The European Space Agency Will Follow up the NASA’s DART Mission
Ahead of the launch, NASA said that to be successful, the orbit would need to shorten by at least 73 seconds.
“This is a 4% change in the orbital period of Dimorphos around Didymos,” John Hopkin’s Dr. Nancy Chabot said. “But if you wanted to do this in the future, you’d want to do it years in advance.”
“Warning time is really key here in order to enable this sort of asteroid deflection to be used in the future as part of a much larger planetary defense strategy,” she added.
However, NASA DART program scientist Dr. Tom Statler warns that one test does not prove scientists can always be successful.
“We should not be too eager to say one test on one asteroid tells us exactly how every other asteroid would behave in a similar situation,” he said. “But what we can do is use this test as an anchor point for our physics calculations in our simulations that tell us how different kinds of impacts in different situations should behave.”
To further perfect and test the system, the European Space Agency will launch the Hera mission, which will send three more spacecraft to Didymos and Dimorphos, in 2026.