Comet 238P / Read, which is hiding in the main asteroid belt, is expected to help unravel the mystery of Earth's appearance.
With the NIRSpec near-infrared camera, the James Webb Space Telescope (JWST) has made another scientific breakthrough.
“We have seen comet bodies in the belt, but only JWST spectral data has proven that there is water ice there,” said study leader Michael Kell, an astronomer at the University of Maryland.
The water vapor near 238P/Read may support theories that water was brought to our planet by comets from space.
Comet 238P/Read was photographed by the James Webb Telescope's NIRCam telescope on September 8, 2022. It shows a dark halo (coma) and a tail characteristic of comets.
Despite their expectations, astronomers did not observe carbon dioxide at 238P/Read, which typically accounts for 10% of a comet's material. It's possible that 238P/Read itself formed in a part of the solar system where there is no CO2.
NASA Image: Comet 238 P/Read and Comet 109 P/Hartley 2 in a Comparison of Spectral Data
The absence of CO2 should be verified by further investigation, or whether main belt comets possess the same properties as 238P/Read.
The main asteroid belt is a region in the solar system located between Mars and Jupiter. As the name implies, the region is primarily a collection of rocky bodies, but occasionally cometary bodies, such as 238P/Read are also found. They are identifiable by the periodic light that appears when they are surrounded by a cloud of dust and gas or a coma.
Comet 238P/Read's sublimation process — water ice evaporates as it approaches the Sun — is shown in the following image by NASA.
The coma and the tail of a comet are formed from a solid icy material that becomes gas as comets approach the sun and warm up, both places that protect water ice from solar radiation.
The term "main-belt comets" is relatively new, and 238P/Read was one of three objects discovered closer to Earth that helped identify this comet family. Only Webb's discovery proved it.
