Do you think aliens in ufos have visited Earth? (And all things UFO)

This could go here or the science thread
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It is the cloud that overshadows the search for alien life: for all the spacecraft sent to faraway worlds, researchers do not really know what to look for when it comes to evidence of life elsewhere.

Now, scientists are claiming progress with the puzzle after training a computer program to distinguish chemical mixtures made by living organisms from those created in more prosaic processes, such as reactions between sunlight and rocks.

In preliminary tests, the program was 90% accurate at telling the difference between samples taken from living organisms, such as shells, teeth and bones, and non-biological samples, such as laboratory chemicals and those found in carbon-rich meteorites.

Unless alien life wanders in front of a robotic lander’s camera, leaves an unambiguous fossil in a rock, or a smear of proteins on a distant world’s surface, such chemical “biosignatures” may be the best hope scientists have of finding past or present life.

Dr Robert Hazen, an astrobiologist at the Carnegie Institution for Science in Washington DC and a senior scientist on the project, said the tool had the potential to revolutionise the search for extraterrestrial life and deepen the understanding of the origins and chemistry of life on Earth.

Armed with the technique, the researchers hope to analyse materials from Mars for signs of life and bring clarity to raging debates over samples considered to be candidates for the earliest known life on Earth.…….

https://www.theguardian.com/science...in-hunt-for-alien-life?CMP=Share_iOSApp_Other