British scientist Jack O'Malley-James from the University of St Andrews, UK, unveiled some very dark plans. He intends to search for dead aliens. Like, it's much easier than getting on the trail of the still alive. Because the dead give off methanethiol gas.
It remains in the atmosphere for 350 years, then turning into a more persistent ethane. If in any stellar system it is possible to detect either one gas or another, then this will indicate that at least animals once lived here. And even intelligent beings.
Where does methanethiol come from in an amount recognizable from Earth - distances of tens and hundreds of light years?
“The gas will come from the mass extinction of living things,” Jack replies.
And creatures die out when the local luminary becomes a red giant - it swells, increasing hundreds of times. And destroys life on the planets that were with him. This is the fate of all stars the size and mass of our Sun.
Someday - maybe in a million years, maybe in a billion and a red giant will swell in the solar system, killing our descendants and making them a source of methanethiol. Unless, of course, the descendants have time to move somewhere else. As Konstantin Eduardovich advised people in his time.
Memorial lights
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Having absorbed and, as a result, incinerated living beings, the red giant begins to shrink. Until it turns into a bright white dwarf the size of the Earth. These are the objects recently examined by astronomers led by Jay Farihi of the University of Leicester, UK.
Scientists were guided by the idea: any white dwarf must keep in itself the remains of the "eaten" by the red giant - the chemical elements that made up the planets and their inhabitants. Therefore, analyzing the emission spectra of white dwarfs, one can try to look for the lines of these elements. What, in fact, astronomers were doing in the Sloan Digital Sky Survey project. In nature, as they say, nothing disappears without a trace.
Farikhi and colleagues studied a total of 146 white dwarfs. They were in areas free of cosmic dust, comets and asteroids. That is, the probability that the stars were attacked by matter brought in from the depths of the universe was minimal. Nevertheless, even a preliminary analysis of the spectrum of dwarfs showed that they are full of calcium. And calcium is both hard rocks and … bones.
Further: where calcium was found, an increased content of hydrogen was also found. And hydrogen is water. Water is life. And calcium and water together are rocky planets with oceans. Like our Earth.
The combination of elements, testifying to the past life, was identified in 109 dwarfs. In fact, most of those surveyed. It is sad, of course, but it turns out that the bright lights of the white dwarfs are commemorative. Like candles in a church …
Life goes on
Phosphorus is the main element of bones and teeth. Phosphorus is also included in the composition of plants that extract it from the soil. Without this element, life - in our understanding of it - is hardly possible. And so Canadian astrophysicists from the University of Toronto recently discovered phosphorus in nebulae that were formed as a result of supernova explosions. Discovered for the first time among other vital elements - hydrogen, carbon, nitrogen, oxygen and sulfur.
The remnants of the exploded star Cassiopeia A, located 11 thousand light years from Earth, were saturated with phosphorus. There is 100 times more of it than anywhere else in the Milky Way. The source of this phosphorus was most likely living things - with bones and teeth. At least plants.
The explosion took place about 300 years ago. And it is possible that even 11,300 years ago, on some planet, Cassiopeia A had life.
As the author of the discovery, Professor Dae-Sik Moon, optimistically believes, the phosphorus left over from the previous inhabitants will be used again - thanks to it, a new life will appear someday.
“The stars explode,” the professor wrote in an article published in the journal Science. “The resulting elements become part of other stars, planets, and ultimately people.
Who knows, what if our phosphorus was once someone's too? For example, Carl Sagan, the famous American astrophysicist and exobiologist, did not deny this possibility. Back in the last century, he said that the source of phosphorus in human DNA and iron in his blood is “star material”.
BTW
Not only cemeteries
Earthlings also betray their presence with "chemistry" - for example, chlorofluorocarbons (CFCs) - substances of exclusively artificial origin. They intensively absorb infrared rays in the spectrum and, therefore, are distinguishable in the atmosphere. Even if the CFC concentration is one part per trillion.
Lisa Kaltenegger from Harvard University suggests looking for chlorofluorocarbons, and along with them, even living brothers in mind, producing this "chemistry". True, current ground-based infrared telescopes - even the most advanced ones - do not yet have enough sensitivity to detect CFCs. But that's enough if you put the right equipment into space. Jim Kasting of Pennsylvania State University (University Park) is confident that with a fleet of powerful enough telescopes in orbit, other nasty things can be found. Such as vapors from solvents, cleaners and refrigerants. And they have their own absorption lines.