Comet Atlas has broken into pieces and the Hubble Space Telescope has produced the sharpest images of the pieces, some the size of a house, providing further evidence that fragmentation of these celestial bodies is likely common.
The Atlas (C / 2019 Y4) was discovered in December 2019 and some astronomers anticipated that next May it could be observed with the naked eye, to become one of the most spectacular in the last two decades.
However, Atlas suddenly began to darken and experts speculated that its ice core could be fragmenting or even disintegrating, which was confirmed by images from an amateur astronomer who photographed several pieces of the comet on April 11.
Hubble took two images, one on April 20, in which about 30 fragments are seen, and another on 23 where about 25 pieces are seen.
These pieces are wrapped in a tail of cometary dust swept by sunlight, the European Space Agency (ESA) said in a statement.
The telescope has distinguished pieces as small as the size of a house and it is estimated that, before breaking, the nucleus should not have been longer than two soccer fields.
Atlas’ appearance changes “substantially” between the two images, according to David Jewitt of the University of California, Los Angeles (USA), head of one of the two teams that have taken the images of the comet with Hubble.
That change in appearance is not known if it is because “the individual fragments turn on and off by reflecting sunlight, as if they were flickering lights on a Christmas tree, or because different fragments appear on different days,” he said.
These images provide “further evidence that fragmentation of comets is likely to be common and may even be the dominant mechanism by which solid, icy nuclei of comets die,” the note added.
Atlas is currently within the orbit of Mars, at a distance of approximately 233 million miles from Earth when the last Hubble observations were made.
The comet will make its closest approach to Earth on May 23 at a distance of approximately 115 million kilometers, and eight days later it will border 59 million miles from the Sun.
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