Comet blast from the past

This pair of NASA/ESA Hubble Space Telescope images of comet C/2019 Y4 (ATLAS), taken on April 20 and April 23, 2020, reveal the breakup of the solid nucleus of the comet. Hubble photos identify as many as 30 separate fragments. The comet was approximately 146 million kilometres from Earth when the images were taken. The comet may be a broken off piece of a larger comet that swung by the Sun 5,000 years ago. 

The comet has been artificially colored in this view to enhance details for analysis.

In a new study using Hubble’s observations, astronomer Quanzhi Ye of the University of Maryland in College Park, reports that ATLAS is a broken-off piece of that ancient visitor from 5,000 years ago. This is because ATLAS follows the same orbital "railroad track" as that of a comet seen in 1844. This means the two comets are probably siblings from a parent comet that broke apart many centuries earlier. The link between the two comets was first noted by amateur astronomer Maik Meyer.