New data suggests that the asteroid Dimorphos is behaving unexpectedly after being hit by a NASA rocket last year.
Recent observations of a space rock about 580 feet (177 meters) wide – NASA deliberately crashed the spaceship On September 26, 2022, as part of the Double Asteroid Redirection Test (DART) mission, Dimorphos showed that it may be rolling in a normally stable orbit around its parent asteroid Didymos. new scientist. Dimorphos also appeared to continue to decelerate in orbit for at least a month after the rocket impact, contrary to NASA’s predictions.
California high school teacher Jonathan Swift and his students first spotted these unexpected changes last fall while observing Dimorphos through their school’s 2.3-foot (0.7-meter) telescope. A few weeks after the DART collision, NASA announced that Dimorphos had decelerated for about 33 minutes in orbit around Didymos. But when Swift and his students studied Dimorphos a month after the impact, the asteroid appeared to have slowed by an additional minute. This suggests that there has been continuous deceleration since the collision.
“The number we got was slightly larger, a change of 34 minutes,” Swift told New Scientist. “It was contradictory to an uncomfortable level.”
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Swift presented the results of the class’s research at the American Astronomical Society meeting in June. The DART team then confirmed that Dimorphos did indeed continue to decelerate in orbit for up to a month after impact. However, their calculations show an additional deceleration of 15 seconds for her instead of 1 minute. A month after the DART crash, the slowdown plateaued.
What caused Dimorphos to steadily slow down for a month before reaching equilibrium? A swarm of space rocks could be to blame: Recent observations of asteroids suggest that vast rocky area It was likely thrown off the surface of Dimorphos during the impact, and was scattered around. A piece of large rock may have fallen on Dimorphos within the first month, slowing its orbit even more than expected, DART team members said. harrison agrusa he told New Scientist magazine.
The DART team plans to release its own report on the unexpected discovery in the coming weeks. But the full answer may have to wait until 2026, when the European Space Agency’s Hera spacecraft is scheduled to arrive at Dimorphos to examine the space crash site up close.
Read more about Dimorphos’ new groove here. new scientist.