With each passing day, more planets are discovered in our Galaxy, and several of these planets may have the potential to harbor life.
Considering this, it is not difficult to imagine that there are alien astronomers who are in a dilemma very familiar to us: Is there life outside our planet?
And if there are alien astronomers on some world in the Andromeda galaxy, for example, would they be able to find Earth? And would they be able to detect the abundant life that exists on our planet?
If Earth were detected by their telescopes, Andromeda’s hypothetical alien astronomers could measure the shimmering light from Earth’s surface as the Sun’s light reflects off our planet’s vegetation. In the same way, astronomers here can detect nuances of color on extrasolar planets, after all, their stars illuminate the surface of the planets and the reflection of this light reaches our telescopes.
But would it be possible for them to know that a certain shade of color means the existence of life?
Yes, this would be possible, and we don’t even need to consider technologies much more advanced than ours, after all, our astronomers can already observe the pigmentation of exoplanets and thus determine their composition.
“Life forms may be dominating other worlds, and through spectroscopy (detection of colors and compositions) we can try to find life. And now we have a database to facilitate this detection”, comments Lisa Kaltenegger, professor of Astronomy and director of the Institute Pale Blue Dots at Cornell University, which studies extrasolar planets and models of habitable rocky planets outside the Solar System.
The institute has a database that other researchers can use freely and could be used in new generations of telescopes that will search for a wide variety of life on exoplanets. A group of scientists has created a color catalog that contains reflection signatures of life forms on Earth that can be detected on the surface of other planets in the Universe.
“This database gives us the first glimpse of what planets out there might look like if they have life forms. Signatures of various life forms on Earth were included, including those from the most extreme regions of the planet”, comments Lisa.
Scientists explain that much of life on Earth has been dominated by microbial life, meaning there is a great chance that we will first encounter unicellular or multicellular life before more complex creatures.
By creating this database, scientists were able to realize the incredible diversity of life that can be detected remotely on exoplanets.
“We have reflection signatures from a wide variety of life forms that are found in isolated and inhospitable places on Earth, including extremophiles,” commented Siddharth Hegde, astronomer at the Max Planck Institute for Astronomy.
Has life on Earth already been detected by possible alien civilizations?
To answer the question above, nothing better than the opinion of one of the most renowned astronomers in the world: Martin John Rees, cosmologist, astrophysicist, president of the Royal Society between 2005 and 2010, master of Trinity College and the University of Cambridge.
According to him, alien life can exist even at a level that is extremely incomprehensible to humans.
“We may be to aliens what chimpanzees are to us, and they may have known our way of life for a long time,” says Rees.
Of course, all of these opinions by Dr. Martin John Rees are considered a hypothetical possibility, which is only based on mathematical calculations and hypotheses according to what we know today.
