Will 2020 Be the Year We Find Intelligent Alien Life?

Currently, the JWST has the best outlook for utilising the onboard spectrometer to find those elements indicating the presence of possible life.

JWST, with its powerful infrared-detection capabilities, is able to see through dense dust with more clarity and detail than any telescope that has come before. That's because infrared wavelengths of light don't scatter off dust particles the way shorter wavelengths do, which means instruments like JWST can effectively see through dust far better than optical instruments like Hubble's.

In a molecular cloud called Chamaeleon I, located some 500 light-years from Earth, data from the JWST has revealed the presence of frozen carbon, hydrogen, oxygen, nitrogen, and sulfur – elements vital to the formation of atmospheres and molecules such as amino acids, collectively known as CHONS*.

"These elements are important components of prebiotic molecules such as simple amino acids – and thus ingredients of life, so to speak," says astronomer Maria Drozdovskaya of the University of Bern in Germany.

In addition, an international team of researchers led by astronomer Melissa McClure of Leiden University in the Netherlands has also identified frozen forms of more complex molecules, such as water, methane, ammonia, carbonyl sulfide, and the organic molecule methanol.

Cold, dense clumps in molecular clouds are where stars and their planets are born. Scientists believe that CHONS and other molecules were present in the molecular cloud that birthed the Sun, some of which were later delivered to Earth via icy comet and asteroid impacts, the same impacts which brought the Earth water.

Although the elements and molecules detected in Chamaeleon I are quietly floating about right now, one day, they could be caught up in planet formation, delivering the ingredients necessary for the emergence of life to new baby planets.

"Our identification of complex organic molecules, like methanol and potentially ethanol, also suggests that the many star and planet systems developing in this particular cloud will inherit molecules in a fairly advanced chemical state," explains astronomer Will Rocha of Leiden Observatory.

"This could mean that the presence of prebiotic molecules in planetary systems is a common result of star formation rather than a unique feature of our own Solar System."

Chamaeleon I is cold and dense, a dark conglomeration of dust and ice that constitutes one of the nearest active star-forming regions to Earth. A census of its composition, therefore, can tell us quite a bit about the ingredients that go into star and planet formation and contribute to an understanding of how these ingredients are incorporated into newly forming worlds.

To determine the chemical composition of the dust in Chamaeleon I, scientists rely on absorption signatures. Starlight traveling through the cloud can be absorbed by elements and molecules therein. Different chemicals absorb different wavelengths. When the spectrum of the light that emerges is collected, these absorbed wavelengths are darker. Scientists can then analyze these absorption lines to determine which elements are present.

JWST peered deeper into Chamaeleon I for a census of its composition than we've ever seen before. It found silicate dust grains, the aforementioned CHONS and other molecules, and ices colder than any measured before in space, at around -263 degrees Celsius (-441 degrees Fahrenheit).

And they found that, for the density of the cloud, the amount of CHONS was lower than expected, including only around 1 percent of the expected sulfur. This suggests that the rest of the materials may be locked up in places that can't be measured – inside rocks and other minerals, for instance.

Without more information, it's difficult to gauge at this point, so more information is what the team intends to get. They hope to obtain more observations that will help them map out the evolution of these ices, from coating the dusty grains of a molecular cloud to their incorporation into comets and perhaps even to seeding planets.

"This is just the first of what we will obtain to see how the ices evolve from their initial synthesis to the comet-forming regions of protoplanetary discs," McClure says.

"This will tell us which mixture of ices – and therefore which elements – can eventually be delivered to the surfaces of terrestrial exoplanets or incorporated into the atmospheres of giant gas or ice planets."

The research has been published in Nature Astronomy.

See: https://www.sciencealert.com/jwst-h...uilding-blocks-in-the-depths-of-darkest-space

* CHONS - is a mnemonic acronym for the four most common elements in living organisms: carbon, hydrogen, oxygen, and nitrogen .

While the acronym CHNOPS, which stands for c arbon, h ydrogen, n itrogen, o xygen, p hosphorus, s ulfur, represents the six most important chemical elements whose covalent combinations make up most biological molecules on Earth.

The chemical elements most prominent in building the structures of the molecules of life are carbon, hydrogen, oxygen, nitrogen, phosphorous and sulfur, sometimes represented mnemonically as CHONPS. These elements combine in a vast number of molecules involved in life processes. Their fitness for making these compounds is related to their relative electronegativities which contribute to their ease of combination.

Although present in relatively small amounts, metal atoms also play a surprisingly important role in the chemistry of life. About a third of the enzymes in the body involve a metal ion as an essential participant. From the electron transport chain to the maintaining of membrane potentials of cells, metals play essential supporting roles for the atoms involved in the major structures of life.

See: http://biologyblurb.weebly.com/chonps.html

Nucleic acids, the building blocks of life as we know it, are made of carbon, hydrogen, oxygen, nitrogen, and phosphorus (CHON P). They are key components of DNA and RNA, wich carry the genetic information of cells. Nucleotides, the building blocks of nucleic acids, are composed of a pentose sugar, a nitrogenous base, and a phosphate group. Proteins, carbohydrates, and lipids are all made of the same elements: carbon, hydrogen, and oxygen. The difference between them is in the arrangement of those atoms. Proteins have a nitrogen atom in addition to the CHON elements, while carbohydrates and lipids do not. Nucleic acids such as DNA and RNA contain phosphorus in addition to the CHON elements. With JWST finding these elements the hunt for the telltale signs of life is on.
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