NASA spacecraft collided with an asteroid

Research on the collision with NASA’s Double Asteroid Redirection Test (DART) ship that changed the orbit of the asteroid pair Dimorphos – Didymos around the Sun was recently published in the journal Science Advances on March 6. According to NASA, this is the first time a man-made object has changed the orbit of a celestial body around the Sun at a measurable level.

The orbital change is very small, only 0.15 seconds, but the team of scientists think that is enough to make a difference. “Given enough time, even a small change can develop into a significant deviation,” said Thomas Statler, a scientist at NASA headquarters in Washington DC.

Statler said that the research team’s high-precision measurement results help reaffirm that dynamic collisions are a promising method to help protect the Earth from danger from asteroids, and also demonstrate that a pair of asteroids can be deflected by the impact of just one of the two “members”.

Rahil Makadia, lead author of the study, and his colleagues monitored “stellar occultation” – the phenomenon in which an asteroid passes in front of a star, causing its light to dim for less than a second – to obtain measurements of the asteroid’s position, speed and shape.

Collecting data is not easy. Based on records of 22 stellar occultations by amateur astronomers around the world and many years of additional observations, the Makadia team measured Didymos’s orbit around the Sun with high precision, and made calculations that could aid future planetary defense efforts.

On September 26, 2022, NASA crashed the DART spacecraft into the asteroid Dimorphos, testing the strategy to protect Earth from potentially dangerous celestial bodies through dynamic collisions. The asteroid pair Dimorphos – Didymos is bound together by gravity, with Didymos being larger with a diameter of about 780 m. Since Dimorphos is smaller, about 160 m in diameter, it will be easier to teleport.

According to estimates for 2022, the test shortened the time to complete one orbit of Dimorphos around Didymos by 32 minutes, exceeding initial expectations. In addition, the collision also ejected 1-10 million kg of material into space.