SCIENCE LAB SCAMPER : MYSTERIOUS COMETS

A Warmer Hangout: Lurking in the asteroid belt : A few mysterious comets.

What do you expect to find in the asteroid belt between Mars and Jupiter? Asteroids, certainly - millions of bits of rocky debris. But recently, astronomers have found a few oddball objects that appear to be misplaced, hiding in the rubble : comets.

And a report in the Monthly Notices of the Royal Astronomical Society indicates a survey dedicated to hunting these misfits might have spied another one.

Scientists identified the suspected comet with the Wide Field Camera of the Issac Newton Telescope on the Canary Island of La Palma. During three observation runs from 2018 through 2020, they watched 534 asteroids, looking for signs of a comet's coma - its ephemeral grassy shell - or a tail made by the sun's radiation pushing against dust in the coma.

The nucleus of a comet is ordinary composed of various ices and dust. As comets approach the sun from the cold fringes of the solar system, the most volatile ices vaporize, creating a coma and tall structure.

The frozen matter in comets lurking at the warmer edges of the inner solar system is mystifying.

''We need to be able to explain how their ice survived for so long,'' said Lea Ferellec, a postgraduate student of astronomy at the University of Edinburgh and an author of the study. [Robin George Andrews]