Here’s an article that opens the door on theories of what alien life may be. This is from the i paper:
Scientists have investigated what will kill the world’s most indestructible species and concluded that almost nothing can – except the death of the sun.
The tardigrade, also known as a water bear, space bear of moss piglet, is a micro-animal with 8 legs that when magnified looks a little like a pig, hippopotamus or bear, and usually lives in moss or lichen. It has also been found in habitats from the Antarctic to the deepest parts of the ocean floor.
A new study carried out by physicists at Oxford University has predicted that the tiny creatures would survive any astrophysical catastrophe, from supernovae exploding nearby to asteroids hitting the Earth, and amy be around for as long as 10 billion years – vastly outliving the human race.
The researchers’ paper, published in Scientific Reports, asks what it would take for the earth to be “Sterilised” …The tardigrade is believed by scientists to be the most indestructible animal on earth. Physicist Dr David Sloan, co-author of the paper, said that he ad his colleagues set out to see “just how fragile this hardiest life is”. What they found was a pleasant surprise… “Although nearby supernovae or asteroid impacts would be catastrophic for people, tardigrades could be unaffected. “Therefore it seems that life, once it gets going, is hard to wipe out entirely. Species, or even entire genera may become extinct, but life as a whole will go on.
The incredible resilience of the tardigrade strengthens the case for life on other planets, according to the researchers. Dr Rafael Alves Batista, another co-author… said:”Tardigrades are as close to indestructible as it gets on earth, but it is possible that there are other resilient species examples elsewhere in the universe. In this context there is a real case for looking for life on Mars and in other areas of the solar system in general.”
Tardigrades have been put through the wringer in scientists’ attempts to kill them. they have survived high doses of radiation and pressure, being released into a vacuum, and being denied any water at all. Scientists believe they have figured out the tardigrade’s secret: parts of their bodies turn into a glass-like substance to cocoon them from dehydration ad other threats. This is down to a special protein, unique to the creature, which can take either a jelly-like or glass-like form, depending on the environment.
These are the conditions researchers have found they can withstand:
Temperatures as low as -272 degrees C or up to 150 deg C for a few minutes and temperatures of -20C for decades
Pressures from almost 0 atmospheres to up to 1,2000 atmospheres
Radiation of 5,000-6,200 grays