The moment the comet disintegrated

Two photos taken with the Hubble space telescope last week show that comet C / 2019 Y4 broke into at least 55 pieces.

C / 2019 Y4 was first detected in December 2019 by the ATLAS astronomical robot system of the University of Hawaii, USA. Astronomers have predicted it will increase its brightness and be visible to the naked eye in May 2020, becoming one of the most spectacular comets in the past two decades.

However, C / 2019 Y4 suddenly dimmed since mid-March, causing many experts to speculate that the comet's core may have been fragmented or disintegrated. This hypothesis was confirmed on April 11 after amateur astronomer Jose de Queiroz first captured three comet fragments.

Using observations from the Hubble space telescope, researchers discovered 55 new fragments, including 30 taken on April 20 and 25 taken on April 23. Comet disintegration is often very fast and unpredictable so such observations are rare.

Hubble captures comet debris on April 20 and 23. Photo: ESA / NASA.

"This is really interesting because it's spectacular and doesn't happen very often. Most comets are too dim to admire. Large-scale fragmentation events like C / 2019 Y4 only happen one or two. times over the past decade, "emphasized research by David Jewitt from the University of California, Los Angeles (UCLA).

Jewitt and colleagues are still not sure about the cause of C / 2019 Y4 disintegration. One idea is that the uneven distribution of force from the sublimation process of the ice inside the core (the direct state transition from solid to gas) caused the comet to crack.

In the latest observations, C / 2019 Y4 is located inside Mars orbit, about 145 million km from Earth. The remnants of the comet will approach our planet on May 23 at a distance of approximately 115 million km and only 37 million km from the Sun eight days later.