According to recent observations from the James Webb Space Telescope, comet 238P/Reed spends its lifetime much closer to the Sun than most comets in the asteroid belt.
„In the past, we’ve seen objects in the main belt that have all the characteristics of comets, but we can only say yes with this precise spectral data provided by Webb, which certainly produces that effect,” says Michael Kelly. The University of Maryland led the study.
But while 238P/Read’s water may have retained the relative warmth of the asteroid belt, the same does not appear to be true for its carbon dioxide.
Molecules typically make up about 10 percent of similar comets, but JWST found none in 238P/Read.
This could indicate that carbon dioxide evaporates more easily than water ice, or that 238P/Read formed in a hot pocket of the Solar System where carbon dioxide was not present.
The team hopes to determine which is more abundant by observing other main belt comets.
„Other main belt comets don’t have carbon dioxide either? It would be exciting to find it anyway,” says Heidi Hammel, who leads JWST’s guaranteed-time observations of solar system objects.