NASA said on Tuesday that a spacecraft deliberately hit an asteroid called Dimorphos and changed its orbit for 32 minutes last month, successfully completing a historic planetary defense mission.
At the press conference, NASA's Double Asteroid Redirection Test (DART) team explained that Dimorphos orbited a larger asteroid Didymos in 11 hours and 55 minutes before the impact. After the impact, astronomers observed that the orbital period is now 11 hours and 23 minutes.
NASA Director Bill Nelson (Bill Nelson) noted that the Disaster Aid Response Team (DART) mission attracted the attention of the world, "feels like a movie plot."
"But it's not Hollywood ," Nelson said. "We show the world the serious attitude of NASA as the defender of the earth."
On September 26, the DART spacecraft hit the Dimorphos asteroid at a speed of more than 14,000 miles per hour. The asteroid weighs about 5 billion kilograms and is about 7 million miles from the earth.
The spacecraft was launched in November, so its impact completed a 10-month journey.
DART's success has won applause from NASA officials and members of the Johns Hopkins Applied Physics Lab team, who have worked on the project for many years.
While Dimorphos has never posed a threat to the earth, DART is a key test designed to divert potential threats to the earth in the future. DART marks the first time that humans use kinetic energy to strike another object in space.
Italian Space Agency Director Giorgio Saccoccia delivered a speech at a NASA meeting on Tuesday, congratulating the team on its successful completion of historic mission. "This is something we are truly proud of on an international level," said Saccocia. The agency contributed to the project and took photos of the asteroid.
Lori Glaze, director of the Planetary Science Department of NASA, said the minimum requirement for changing the asteroid's orbital period is 73 seconds, and said the 32-minute change is "very significant."
She said at the press conference: "This is really a fascinating thing and learning will last for a long time."
Glaze said that ground telescopes have observed impacts in large numbers around the world.
James Webb and Hubble (Hubble) space telescopes also captured images, which detailed the flow of Dimorphos matter tracking the asteroid from the center of the impact.
NASA still has work to do, including more observations and analysis of the impact, and the development of the Gemini God model.
The European Space Agency has a follow-up mission called Hera, which will launch a spacecraft to Didymos in 2024. The spacecraft will arrive in 2026 and will provide more details about the collision with Dimomos.
In the next decade, NASA's next priority mission is to count asteroids or other space objects in the solar system with a diameter of at least 140 meters.
These may pose a threat to the earth, and it is estimated that only about 40% of large space objects have been identified.
NASA will also explore a "fast response" task to detect threats faster. In theory, rapid reconnaissance will provide space agency and world leaders with enough time to deflect the object.
