Science & Technology

NASA confirms that DART impact mission altered asteroid’s orbit

Washington, Oct 11 (EFE).- NASA confirmed on Tuesday that the DART space probe that was steered to hit the tiny asteroid Dimorphos, located 11 million kilometers (6.8 million miles) from Earth, managed to alter the rocky body’s orbit around its mother asteroid, just as planned.

The director of the US space agency, Bill Nelson, said that before the impact Dimorphos was taking 11 hours and 55 minutes to orbit a larger asteroid named Didymos, with which it forms a double-asteroid system.

The unmanned DART space probe reduced that orbit by 32 minutes, with a margin of error of two minutes, and Nelson said that “This mission shows that NASA is trying to be ready for whatever the universe throws at us,” adding that the space agency would have considered it a success if it had reduced the asteroid’s orbital period by just 10 minutes.

Dimorphos’s orbit was moved about 10 meters (33 feet) closer to Didymos and the change in its orbit will be permanent.

This was the first time in human history that space authorities had tried to change the trajectory of a celestial body with an eye to protecting Earth from asteroids similar to the one that wiped out the dinosaurs 66 million years ago when it crashed into what is today the Yucatan Peninsula.

The impact of the DART probe, the acronym standing for Double Asteroid Redirection Test, took place on Sept. 26 and live images from the probe’s camera were shown as it approached – and ultimately hit – the asteroid. The probe – which was destroyed on impact – was about the size of a refrigerator and the mission cost some $330 million.

“DART’s success provides a significant addition to the essential toolbox NASA and humanity should have to protect Earth from a devastating impact by an asteroid,” Nelson said. “This mission required incredible preparation and precision to make impact with an asteroid almost 7 million miles away. NASA exceeded expectations on all counts.”

Dimorphos (meaning “two forms” in Greek) is an asteroid 160 meters (525 feet) in diameter similar to a little moon circling Didymos, which is 780 meters (just under half a mile) in diameter and whose name means “twin” in Greek.

Didymos orbits the Sun at a distance of 1.0-2.3 astronomical units (i.e. 1 to 2.3 times the distance from the Earth to the Sun) once every 770 days.

The double-asteroid pair was selected by NASA for the experimental mission because they do not pose any danger to Earth and thus the DART probe’s collision with the smaller body stood no chance of altering its orbit so that it might strike our planet.

NASA said that the conclusions reached on Tuesday about bullseye impact constitute just “the beginning” of all the information it hopes to get from the mission, which was designed to test existing technology in case a celestial body is found to pose a direct danger to Earth.

The mission was mounted to slightly shift the orbit of the moonlet asteroid, not to destroy it. One of the main researchers working on DART, Nancy Chabot, said that the idea was not to explode the asteroid into “millions of pieces” but rather to give it a “little push.”

The space agency made clear on Tuesday that one of the key elements in making similar missions to divert potential planet-killing asteroids from striking Earth successful is early detection of the danger.

The more time space authorities have to mount a mission to provide that “little push,” the better, said Lori Glaze, the head of NASA’s Planetary Science Division.

Astronomers will now continue studying the images of Dimorphos to get an estimate of its mass and composition.

Within the next four years, according to an additional statement, the Hera Project mounted by the European Space Agency is also scheduled to carry out detailed studies of both Dimorphos and Didymos, focusing in particular on studying the crater left by the DART probe and making precise measurements of the mass of Dimorphos.



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