NASA has confirmed that DART, the first planetary defense mission, has achieved its goal: not only did it crash into Dimorphos, an asteroid 11 million kilometers from Earth in a feat only comparable to shooting a mosquito 70 kilometers away; but he has managed to divert its trajectory and prove that humanity has a plan in case a space rock threatens to collide with our planet.
The person in charge of giving the news was the administrator of NASA, Bill Nelson: “All of us have a responsibility to protect our home planet. After all, it is the only one we have”, said Nelson during the press conference. “This mission shows that NASA is trying to be ready for whatever the universe throws at us. The agency has shown that we are serious about defending the planet and demonstrates our commitment and that of all NASA partners.”
A shorter orbit of 32 minutes
Before the DART impact, which took place on Monday, September 26, Dimorphos took 11 hours and 55 minutes to complete one lap of Didymos, a larger asteroid that it orbits. Since the DART collision, astronomers have found that the spacecraft’s impact has altered Dimorphos’s orbit by 32 minutes (with an uncertainty margin of plus or minus 2 minutes), shortening the orbit from 11 hours and 55 minutes to 11 hours and 23 minutes. NASA had set out to divert it for a minimum of 73 seconds, which is why this mark has been exceeded more than 25 times.
“This result is an important step toward understanding the full effect of DART’s impact on its target asteroid,” he said. Lori Glaze, director of NASA’s Planetary Science Division. “As new data comes in every day, astronomers will be able to better assess how this data can be used in the future to help protect Earth from a collision with an asteroid if we ever discover one in our path.”
Looking at each grain
Although the team will continue to collect data on the new orbit of Dimorphos, the next step will be to learn more about the impact itself and how the material is projected from the rock into space, creating a kind of ‘tail’ like that of a comet. . “The recoil from this debris explosion substantially enhanced DART’s thrust against Dimorphos, a bit like a jet of air coming out of a balloon sends the balloon in the opposite direction,” they explain in a statement from NASA.
But to fully understand the recoil effect of the ejection, more information is needed about the physical properties of the asteroid, such as its surface features and how compact it is. “DART has given us some fascinating data on the properties of asteroids and the effectiveness of a kinetic impactor as a planetary defense technology,” he said. Nancy Chabot, DART coordinator at the Johns Hopkins Applied Physics Laboratory (APL). “The DART team continues to work on this rich data set to fully understand this first planetary defense test to deflect asteroids.”
For this analysis, astronomers will continue to study Dimorphos images from DART’s terminal approach and from the Light Italian CubeSat for Imaging of Asteroids (LICIACube), provided by the Italian Space Agency, to approximate the mass and shape of the asteroid. “We have to be very proud of this mission and its result,” he explained for his part. Giorgio Saccocciarepresentative of the Italian Space Agency.
Approximately four years from now, the Hera mission of the European Space Agency it is also planned to conduct detailed studies of Dimorphos and Didymos, with a particular focus on the crater left by the DART collision and a precise measurement of Dimorphos’ mass.