Could invisible aliens really exist among us? An astrobiologist explains

They probably won’t look anything like this. Credit: Martina Badini/Shutterstock

Life is pretty easy to recognise. It moves, it grows, it eats, it excretes, it reproduces. Simple. In biology, researchers often use the acronym “MRSGREN” to describe it. It stands for movement, respiration, sensitivity, growth, reproduction, excretion and nutrition… More about this article in link…

https://phys.org/news/2020-01-invisible-aliens-astrobiologist.html