The James Webb Telescope finds water around a comet in the main asteroid belt

The James Webb Space Telescope has just made its second breakthrough observation in as many weeks. The researchers used the observatory’s near infrared camera reveal First known instance of water vapor around a main asteroid belt comet, also known as a main belt comet. Scientists thought comets could keep water ice relatively close to the sun, but they didn’t have definitive proof yet. They generally expected comets to sit in the Kuiper Belt or the Oort Cloud, both of which are far enough from the Sun that the ices can last.

However, the results created a new puzzle. While carbon dioxide typically accounts for 10 percent of the potential evaporation material in a comet, Webb’s instruments detected nothing in the reading. The research group speculates that the carbon dioxide either dissipated over billions of years, or that Reed formed in a relatively temperate part of the solar system that had no carbon dioxide.

Reid was one of the first bodies used to create the main belt class of comets. The Webb telescope is the first instrument powerful enough to study these comets in detail.

More observations will be needed to understand whether Reed’s lack of carbon dioxide is just a fluke or is common to other main belt comets. Whether or not that’s the case, team member Stephanie Milam suggests that a sample-collecting mission could be useful in learning more about such comets. It will certainly be more practical than the other missions — the Kuiper Belt starts roughly at the edge of Neptune’s orbit, while the Oort Cloud is nearly light-years away.