The James Webb Space Telescope detects the coldest ever interstellar ice
NASA’s newest space telescope not only extends astronomers’ view deeper into the universe, but it also reaches cooler temperatures than scientists have done before.
the James Webb Space Telescope (JWST or Webb), the most powerful space observatory to date, peered deep into a dense molecular cloud and found a rich variety of interstellar ices – including a host of molecules important to life. The discoveries were made in frigid temperatures of minus 440 degrees Fahrenheit (minus 263 degrees Celsius), the coldest snow ever measured.
Klaus Pontopidan, an astronomer at the Space Telescope Science Institute and author of a new study describing the work, said in a statement statment.
Related: The best James Webb Space Telescope images of all time (gallery)
Webb studied a neighborhood that scientists call Chameleon I. It is located in the southern constellation Chameleon, about 500 light-years from a landIt’s one of the closest star– Forming regions, with dozens of pockets alive with young stars. The region belongs to a family that astronomers have long thought were holes in the sky: Dark particle clouds It is so dense with gas and dust that visible light from background stars fails to penetrate it.
Clouds like Chameleon I are stellar nurseries. Their collapse over time leads to the formation of stars and possible rocky planetary systems. However, the chemical composition of these systems and any building blocks for life they may contain are determined by the ice embedded deep within the molecular cloud.
Now, thanks to Webb’s powerful instruments, including the Near Infrared Depth of Penetration Camera (NIRCam), astronomers have investigated Chameleon I’s dusty core and detected ices in their early stages of development — just before the cloud’s core collapsed to form protostars.
The team used light from two background stars, NIR38 and J110621, to illuminate Chameleon 1 at infrared wavelengths. Different cloud particles trapped in the ice absorb starlight at different wavelengths of infrared radiation. The astronomers then studied the chemical signatures, which appeared as dips in the resulting spectral data. This data helped the team determine how much of the particles were in the first chameleons.
“Original Cloud of Ice”
The team detected an expected set of key life-supporting compounds: water, carbon dioxide, carbon monoxide, methane, and ammonia. The observations also revealed signs of carbonyl sulfide ice, allowing for the first measurements of how much sulfur—another element needed by Earth’s life, at least—is present in molecular clouds. The researchers also discovered the simplest complex organic molecule, methanol, which is believed to be a molecule unmistakable indicator The early complex chemical processes that occur in the early stages of star and planet formation.
“This is the first time that researchers have been able to study the formation of so-called prestellar ice near the center of a molecular cloud,” Melissa McClure, an astronomer at Leiden Observatory in the Netherlands and lead author of the study, said in a sec. statment.
The fact that the team detected methanol indicates that the stars and planets that will eventually form in this cloud will “inherit the molecules in a fairly advanced chemical state,” said Will Rocha, another astronomer at the Leiden Observatory. statment. “This could mean that the presence of prebiotic molecules in planetary systems is a common consequence of star formation, rather than a unique feature of our solar system.”
In addition, methanol can be combined with other simpler ices to form amino acids, which are the building blocks of proteins. These may include compounds glycine One of the simplest amino acids. In 2016, in Europe Rosetta spacecraft Detection of glycine in ambient dust Comet 67P/ Churyumov-Gerasimenko.
Why are grains of dust and ice important for building habitable exoplanets?
Molecular clouds like Chameleon 1 start out as scattered regions of dust and gas. Ice containing important particles necessary for life, including the latest discoveries by astronomers, forms on the surfaces of dust grains.
As the clouds accumulate into clumps of gas and head towards star formation, these icicles grow in size while remaining in layers on dust grains. Many of the chemical reactions needed to create the complex molecules required for life are accelerated when they occur on a solid surface such as a grain of dust rather than in the gaseous form. In this way, dust grains become essential catalysts for the evolution of simple organic elements into complex molecules that can eventually form the building blocks of life.
Furthermore, as stars begin to form and temperatures increase, the volatile nature of this ice allows it to revert to gases, which is what ends up in the hot cores of stars and eventually in the planets’ atmospheres. The discovery of these pure ices within Chameleon 1 allows astronomers to track the craft’s journey all the way from being on dust grains to incorporating into the cores and atmospheres of future stars and outer planets.
Using Webb’s data, astronomers already know that a group of elements detected in Chameleon I is much less abundant than scientists expected, given the density of the cloud. For example, the researchers detected only 1% of the expected sulfur, 19% of the expected oxygen and carbon, and only 13% of the expected total nitrogen. The best explanation, the study authors note, is that these elements may be trapped in other ices that do not appear at the wavelengths the team observed.
In the coming months, the team plans to use Webb’s data to calculate dust grain sizes and ice shapes.
“These observations open a new window into the formation pathways of the simple and complex molecules needed to make the building blocks of life,” said McClure.
The research is described in a paper (Opens in a new tab) Published Monday (January 23) in the journal Nature Astronomy.
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