May 16th, Washington James Webb Space Telescope, a highly advanced instrument, has made history by discovering water surrounding a comet in the main asteroid belt.
Water vapour was verified by astronomers using Webb’s NIRSpec (Near-Infrared Spectrograph) instrument, suggesting that water ice from the early solar system may be maintained there.
According to senior author and University of Maryland astronomer Michael Kelley, “in the past, we’ve seen objects in the main belt with all the characteristics of comets, but only with this precise spectral data from the Webb can we say yes, it’s definitely water ice that is creating that effect.”
Water ice from the early solar system may be retained in the asteroid belt, as shown by Webb’s observations of Comet Read, as stated by Kelley. Nature reported the study’s findings.
Main belt comets, like Comet Read, are found in the main asteroid belt but sometimes exhibit cometary characteristics, such as a coma and tail. Comet Read was one of the three comets used to create the new categorization of “main belt comets.”
Comets were formerly thought to exist in the Kuiper Belt and Oort Cloud, beyond Neptune’s orbit, where their icy surfaces would be protected from the Sun’s heat.
Comets are distinguished from asteroids by their coma and streaming tail, which are formed from frozen material that vaporises as the comets approach the Sun.
Water ice has been suspected to be retained in the warmer asteroid belt within Jupiter’s orbit for quite some time, but until Webb’s discovery, confirmation was lacking.
Carbon dioxide (CO2), which makes up around 10% of the volatile material in a comet and is quickly vaporised by the Sun’s radiation, was not found in Comet 238P/Read.
The team believes that Comet Read originated with carbon dioxide (CO2) but has since lost it due to rising temperatures.
According to Kelley, “being in the asteroid belt for a long time could do it” because “CO2 vaporises more easily than water ice,” meaning that it could slowly seep out over a period of billions of years. He also mentioned the possibility that Comet Read evolved in an unusually heated region of the solar system devoid of carbon dioxide.
Expanding the study beyond Comet is the next stage. Compare these comets to those in the main belt by reading on.
Webb’s confirmation of water preservation as close as the asteroid belt piques the interest of Webb’s deputy project scientist for planetary science, Stefanie Milam, who thinks it would be fascinating to follow up on this discovery with a sample collection mission and find out what else the main belt comets can teach us.
