Bull’s-eye: NASA’s DART spacecraft successfully changed the orbit of asteroid Dimorphos by bumping into the rocky body two weeks ago, according to the space agency.
The test shows humanity has the ability to stop an asteroid from hitting the planet, NASA Administrator Bill Nelson said at a news conference Tuesday.(Opens in a new window). “If an Earth-threatening asteroid is discovered and we can see it far enough away, this technique could be used to deflect it,” he added.
DART (Double Asteroid Redirection Test) was a spacecraft the size of a refrigerator. When it collided with Dimorphos on September 26, it was traveling at 14,000 miles per hour, causing a noticeable impact that telescopes and radar images were able to capture.
NASA: This image from ASI’s LICIACube shows the ejecta plumes streaming from asteroid Dimorphos after NASA’s Double Asteroid Redirect Test. (NASA)
Before the collision, the asteroid Dimorphos took 11 hours and 55 minutes to orbit its larger parent asteroid, Gemini, which is currently traveling around the Sun. Since then, astronomers around Earth have been watching the orbit of asteroid Dimorphos to see what has changed.
NASA: The green circle shows the location of asteroid Dimorphos, which orbits the larger asteroid, Didymos, seen here as the bright line in the middle of the images. The blue circle shows where Dimorphos would be if its orbit had not been changed by NASA’s DART mission. (NASA)
“Now the team has confirmed that the impact of the spacecraft (DART) changed Dimorphos’ orbit around Gemini by 32 minutes and therefore successfully moved its orbit,” Nelson said. “In other words, DART reduced the 11 hour 55 minute orbit to 11 hours 23 minutes. And he moved it to another location.”
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Nelson added that NASA would consider the DART mission a success if it had only slowed the asteroid’s orbit by about ten minutes. Instead, the craft was able to decelerate the orbit by three times more than that.
“This is a watershed moment for planetary defense and a watershed moment for humanity,” Nelson said.
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