On March 21, Comet 252P/LINEAR buzzed Earth during one of the closest recorded cometary encounters with our planet and the Hubble Space Telescope locked onto the icy vagabond as it ran away into the night, imaging its rotating tail.
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252P was notable for a few reasons. Not only was it a very close call, it is also partnered with another comet, P/2016 BA14, indicating that some time in the pair's past, they were likely both part of the same object.
After generating world-wide interest, Hubble watched 252P zoom away from Earth and the sun and on April 4 it took a series of images to reveal 252P's dusty tail was rotating. Immediately, astronomers could conclude that, like a spinning lawn sprinkler, water vapor was blasting from the comet nucleus' sublimating ices as it rotated, launching dust into space.
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These visible light observations were made by Hubble's Wide Field Camera 3 when the comet was 8.7 million miles away and the time interval between each frame of the animation (top) is between 30 to 50 minutes.
Although the nucleus is far too small for Hubble to resolve (astronomers estimate it to be less than a mile across), the rate of the tail spin gives us an insight to the rate of the nucleus' spin and could therefore reveal some information about the object's history as well as the quantity of volatiles it contains.
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Comets can be "spin up" through solar radiation heating, a factor that may have led to the original object breaking up in the solar system's history.
Comet 252P/LINEAR will return to the inner solar system in 2021, but will not come close to our planet for the foreseeable future.