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Scientists Might Unveil a Game-Changing Alien Life Signature—but Big Hurdles Remain

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 The search for alien life is one of the most captivating scientific quests of our time. With the discovery of thousands of exoplanets, astronomers are now focused on identifying clear biosignatures—chemical indicators in planetary atmospheres that could reveal the presence of life.


 A recent study by researchers at the University of California, Riverside (UCR)
 , suggests that methyl halides could be one such biosignature. These gases, composed of one carbon and three hydrogen atoms bonded to a halogen, are naturally produced by bacteria, algae, fungi, and some plants on Earth, but they are not known to form through abiotic (non-biological) processes.


 This makes them a highly promising target in the search for life. However, there’s a significant obstacle: our current telescopes, including the James Webb Space Telescope (JWST), are not yet powerful enough to detect them in Earth-sized exoplanets. Researchers believe, however, that a different class of planets—Hycean worlds—could provide a solution.

<h2>
 What Are Methyl Halides and Why Do They Matter?
</h2>

 In the hunt for
 alien life
 , scientists rely on finding molecules that are primarily produced by biological organisms. Traditionally, gases such as oxygen, methane, and water vapor have been considered promising biosignatures, but they are not definitive proof of life since they can also be created through geological and atmospheric processes.


 
 Methyl halides, however, are different.
 
 These gases are released into Earth’s atmosphere by biological activity but are not known to be created through purely chemical or geological processes. This makes them particularly valuable as potential biosignatures. If methyl halides were detected in the atmosphere of an exoplanet, it could strongly suggest the presence of life.


 “Unlike an Earth-like planet, where atmospheric noise and telescope limitations make it difficult to detect biosignatures, Hycean planets offer a much clearer signal,” explains
 
 Eddie Schwieterman
 
 , an astrobiologist at UCR.


 The study suggests that
 
 Hycean planets
 
 , which are water-rich worlds orbiting
 
 red dwarf stars
 
 , may provide the ideal conditions for these gases to accumulate in detectable amounts.

<h2>
 Why Can’t We Detect These Biosignatures Yet?
</h2>

 The
 
 James Webb Space Telescope (JWST)
 
 has revolutionized exoplanet research by providing detailed observations of atmospheres, but even JWST has limits.


 ・Size Matters: Earth-sized exoplanets are too small and dim for JWST to observe directly. It can detect atmospheric signatures from larger gas giants, but analyzing smaller rocky planets remains a significant challenge.


 ・Signal Strength: Even if methyl halides exist in an exoplanet’s atmosphere, the concentration may be too low for JWST to detect using current techniques.


 ・Interference from Host Stars: Many promising exoplanets orbit red dwarf stars, which produce intense radiation and atmospheric noise that could obscure potential biosignatures.


 Because of these challenges, Schwieterman and his colleagues suggest that
 
 Hycean planets
 
 —which have thick hydrogen atmospheres and orbit dimmer red dwarf stars—could provide a better opportunity for detection.

<h2>
 Hycean Planets: A New Hope for Detecting Alien Life
</h2>

 Hycean planets are a relatively new category of exoplanets that astronomers believe could be more
 
 hospitable to microbial life
 
 than Earth-like planets. They are:


 ・Larger than Earth, but not as massive as gas giants


 ・Covered in global oceans, potentially resembling Earth’s early conditions


 ・Likely to retain biosignature gases, including methyl halides, in their thick atmospheres


 Because
 
 Hycean planets
 
 have thick atmospheres rich in hydrogen, they can allow methyl halides to accumulate in larger amounts than Earth-like planets, making them easier to detect with JWST and future space telescopes.


 If life exists on Hycean worlds, methyl halides could be one of the first biosignatures we detect beyond Earth.


 
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Scientists Might Unveil a Game-Changing Alien Life Signature—but Big Hurdles Remain

Unknown biodiversity, biology, ecology, exoplanets, life sciences

The search for alien life is one of the most captivating scientific quests of our time. With the discovery of thousands of exoplanets, astronomers are now focused on identifying clear biosignature…

British Scientist Unearths Oldest Water in History and Takes a sip

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 A scientist who found the oldest water ever discovered on Earth decided the best course of action was, of course, to drink it.


 Professor Barbara Sherwood Lollar was leading a team of geologists studying a
 Canadian
 mine in 2016 when she made the remarkable discovery.


 The flowing water about three kilometres below the surface was between 1.5bn and 2.6bn years old, according to tests, making it the oldest
 water
 found on Earth.


 “When people think about this water they assume it must be some tiny amount of water trapped within the rock,” said Prof Sherwood Lollar.


 “But in fact it’s very much bubbling right up out at you. These things are flowing at rates of litres per minute – the volume of the water is much larger than anyone anticipated.”


 Upon tasting the
 ancient
 water, she found that it was “very salty and bitter” and “much saltier than seawater”.


 That was an encouraging sign, because saltier water tends to be older. In this case, where the water has been ageing for billions of years, it is hardly surprising.


 “If you’re a geologist who works with
 rocks
 , you’ve probably licked a lot of rocks,” said Sherwood Lollar.


 Her team also found that life had once been present in the water, by looking at the sulphate – the composition of
 salts
 – in it.


 “We were able to indicate that the signal we are seeing in the fluids has to have been produced by microbiology – and most importantly has to have been produced over a very long time scale.


 “The microbes that produced this signature couldn’t have done it overnight.


 “This has to be an indication that organisms have been present in these fluids on a geological timescale.”


 Fortunately, the scientist had no terrifying
 sci
 -fi movie-esq reaction to drinking the ancient water, and lived to tell the tale.


 The paper was published in
 Nature
 in 2016.


 
 This article was first published on October 26, 2023
 


 
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British Scientist Unearths Oldest Water in History and Takes a sip

Unknown drinking water, food and drink, life sciences, science, water

A scientist who found the oldest water ever discovered on Earth decided the best course of action was, of course, to drink it. Professor Barbara Sherwood Lollar was leading a team of geologists stu…