by Scientists using the James Webb Space Telescope (JWST) is the coldest ice in the deepest regions of an interstellar molecular cloud so far observed and measured. The frozen molecules measured minus 440 degrees Fahrenheit (minus 263 degrees Celsius), according to new research published January 23 in the journal Natural Astronomy (opens in a new tab).
Molecular clouds, made up of frozen molecules, gases and dust particles, act as the birthplace of stars and planets – including habitable planets, like ours. In this latest research, a team of scientists used JWST’s infrared camera to investigate a molecular cloud called Chameleon I, about 500 light years from Earth.
Within the dark, cold cloud, the team identified frozen molecules such as carbonyl sulphur, ammonia, methane, methanol and more. These molecules will be part of the hot core of a growing star, and possibly part of future exoplanets, according to the researchers. They also hold the building blocks of habitable worlds: carbon, oxygen, hydrogen, nitrogen and sulphur, a molecular cocktail known as COHNS.
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“Our results provide insights into the early, dark chemical stage of ice formation on the interstellar dust grains that will grow into the centimeter-sized pebbles from which planets form,” lead study author Melissa McClure (opens in a new tab)said an astronomer at the Leiden Observatory in the Netherlands in a statement (opens in a new tab).
Dusty nursery
Stars and planets form within molecular clouds like Chameleon I. Over millions of years, the gases, ice and dust collapsed into larger structures. Some of these structures are needed to become the cores of young stars. As stars grow, they sweep up more and more matter and become hotter and hotter. When a star forms, the remaining gas and dust around it form a disk. Once again, this matter begins to collide, stick together and eventually form larger bodies. One day, the clumps could be planets. Even habitable ones like ours.
“These observations open a new window on the formation pathways for the simple and complex molecules needed to make the building blocks of life,” McClure said in the statement.
The JWST sent back its first images in July 2022, and scientists are currently using the $10 billion telescope’s instruments to demonstrate what kinds of measurements are possible. To identify molecules within Chameleon I, the researchers used light from stars located outside the molecular cloud. As the light shines towards us, the dust and molecules within the cloud absorb it in specific ways. These absorption patterns can then be compared to known patterns determined in the laboratory.
The team also found more complex molecules that they cannot specifically identify. But the result proves that complex molecules form in molecular clouds before the growing stars use them up.
“Our identification of complex organic molecules, such as methanol and possible ethanol, also suggests that the many star and planetary systems that develop in this particular cloud will inherit molecules in a fairly advanced chemical state,” a joint study author Will Rocha (opens in a new tab), an astronomer at the Leiden Observatory, said in the statement. “
Although the team was delighted to observe COHNS within the cold molecular soup, they did not find as high a concentration of molecules as expected in a dense cloud like Chameleon I. How habitable life like ours found its ICY COHNS. still a big question among astronomers. One theory is that COHNS were delivered to Earth by collisions with icy comets and asteroids.
“This is the first in a series of spectral images that we will obtain to see how the ices develop from their initial synthesis to the comet-forming regions of protoplanetary disks,” McClure said in the statement. “This will tell us what mixture of ices – and therefore what elements – can eventually be delivered to the surfaces of terrestrial exoplanets or incorporated into the atmospheres of gas or ice giant planets.”
