Hubble continues to make one bold statement after another about its capabilities even after years of service and the latest statement is through one of the sharpest and most detailed observations of a comet disintegrating over 60 miles from Earth.
Observed and imaged over the course three daily this January, the 4.5-billion-year-old comet, named 332P/Ikeya-Murakami, or Comet 332P, is said to have disintegrated 67 million miles from Earth. According to details provided by the Hubble Space Telescope, there are as many as 25 building-size blocks made of a mixture of ice and dust that are drifting away from the comet at a leisurely pace, about the walking speed of an adult with debris scattered along a 3,000-mile-long trail.
Experts are of the opinion that the images reveal that horrific fate of comets as they approach the Sun. Comet 332P was 150 million miles from the sun, slightly beyond the orbit of Mars, when Hubble spotted the breakup. David Jewitt of the University of California at Los Angeles explains that while scientists are aware about disintegration of comets, there is hardly any insight into why and how the disintegration happens.
Hubble enabled scientists to see the really tiny, faint bits of the comet and observations over the course of three days has enabled scientists to watch the disintegration process as it happens from day to day. The three-day observations reveal that the comet shards brighten and dim as icy patches on their surfaces rotate into and out of sunlight. Their shapes change, too, as they break apart. The icy relics comprise about 4 percent of the parent comet and range in size from roughly 65 feet wide to 200 feet wide. They are moving away from each other at a few miles per hour.
The Hubble images show that the parent comet also changes brightness cyclically, completing a rotation every two to four hours. A visitor to the comet would see the sun rise and set in as little as an hour. The comet is also much smaller than astronomers thought, measuring only 1,600 feet across, about the length of five football fields.
Comet 332P was discovered in November 2010, after it surged in brightness and was spotted by two Japanese amateur astronomers, Kaoru Ikeya and Shigeki Murakami.
The results will appear in the Sept. 15, 2016, issue of The Astrophysical Journal Letters.