The demise of a spacecraft is usually quite poignant. But two weeks ago, NASA celebrated its destruction.
On Sept. 26, NASA conducted the final phase of the Double Asteroid Redirection Test (DART), in which a spacecraft deliberately crashed into the asteroid Dimorphos to investigate whether such an impact could deflect an Earth-bound stellar object. A successful collision was the first cause for celebration, but now there is even more reason to celebrate. NASA has officially declared the DART mission a success and revealed in a press conference today that Dimorphos’ orbit has changed significantly as a result of the impact.
When DART crashed into Dimorphos, planetary defense researchers hoped the spacecraft’s kinetic energy would be transferred to the asteroid, altering its path. In theory, the same method could be used to protect Earth from an incoming asteroid. (For what it’s worth, neither Dimorphos nor the larger asteroid Didymos, which it orbits, pose a threat to our planet.)
For the mission’s success, DART had to change Dimorphos’ nearly 12-hour orbit around Didymos by at least 73 seconds. After two weeks of observations, the team revealed a 32-minute change in Dimorphos’ orbital time — more than 25 times longer than the measure of success.
“This result is an important step in understanding the full effect of DART’s impact with its target asteroid,” Lori Glaze, director of NASA’s Planetary Science Division, said in a statement. press release. “As new data comes in every day, astronomers will be better able to assess whether, and how, a mission like DART could be used in the future to protect Earth from a collision with an asteroid if we ever discover one heading our way. coming. “
The DART team will continue to observe Dimorphos and collect data from ground-based observatories; the Italian space agency’s LICIACube satellite, which imaged the collision up close; and finally the European Space Agency’s Hera mission, which will investigate Dimorphos in about four years’ time. The top image of LICIACube shows debris pouring into space from the stricken asteroid.
“DART has provided us with some fascinating data on both asteroid properties and the effectiveness of a kinetic impactor as a planetary defense technology,” said Nancy Chabot, the DART coordination leader at the Johns Hopkins Applied Physics Laboratory, which managed the mission for NASA. . “The DART team continues to work on this rich data set to fully understand this first planetary defense test of asteroid deflection.”
While we’re still a long way from full-fledged planetary defense capabilities, at least DART has shown that we probably don’t need to send Bruce Willis into space to protect us — an autonomous spacecraft would do the trick.