We find new exoplanets every day, we found more than 3000. We’re very close to finding a planet very similiar to Earth that harbors life. What do you think about possibility of some other civilization discovering our planet and thinking “Wow, this planet may harbor life, it’s “OurPlanet”‘s size and in it’s star habitable zone?” How would our planet look like to a life forms like us located light years away?
Andrew Rader (SpaceX engineer, MIT PhD, author)
The answer to the question depends on their detection technology. If they merely found an average G2V star with 8-10 planets around it with a couple (Earth and maybe Mars) in the habitable zone, they’d probably simply add it to their catalog. If they were able to measure the composition of Earth’s atmosphere, they might realize that life thrived here and wonder what kind of life. If they were able to monitor and track our atmospheric composition over time, they might realize that an advanced civilization existed, but also one causing precarious changes in atmospheric concentrations of gasses like C02. This might raise the question of how wise our civilization really is, and how long it might survive.
Fraser Cain (publisher at Universetoday.com, co-host of Astronomy Cast)
Any alien civilization that turned a powerful telescope on Earth over the last 500 million years or so would have known there’s life here by the composition of our atmosphere. And if they were sophisticated enough, they’d know what stage of the industrial evolution we’re in because of the pollution in our atmosphere. The fact that there’s life on Earth is no secret to advanced civilizations. And this is the technique that we’re about to use to find aliens around us with the next generation telescopes like James Webb.
Antonio Paris (Astronaut Candidate, Astronomy Professor, Planetary Scientist, Space Science Author)
There are potentially billions of planets in our Milky Way alone. Some of these planets could harbor intelligent life capable conducting a survey of planets as well. However, we do no have any information to suggest that an intelligent species elsewhere in the Universe can understand astronomy, or for that matter planetary science, like we do. Humans, for example, have a predisposed bias to look for planets similar to Earth because we concentrate on “comparative science”, meaning we search the cosmos for “Earth-like” planets. An intelligent species that has evolved in a planet completely different than earth, including an atmosphere not comparable with Earth, could perhaps discover Earth but categorize our planet as “non-inhabitable. It is a matter of perspective.
Nicole Guggliucci (“Noisy astronomer”, blogger, educator, post-doc)
I just finished up my “Life Beyond Earth” class for the semester, so this topic has been on my mind a bit. I imagine that a civilization light years away would be interested in the presence of oxygen in our atmosphere, which typically only exists in stable form when being put out by photosynthetic life forms. A nearby civilization would probably be able to pick up our radio transmissions, but that’s IF they had sensitive enough receivers and IF they were looking in the right place. But that’s only a small bubble around us, less than 100 light years or so. I think the oxygen in our atmosphere would give away signs of life far before any of our human-created signals reached another civilization. We’ll be doing the same, by the way, as we analyze exoplanet atmospheres with the present and next generation of telescopes.
Ciro Villa (technologist, application developer, STEM communicator)
It’s an exciting and somewhat scary thought at once to think of the possibility of an extraterrestrial civilization becoming aware of our presence in the Universe with a whole series of other emotions mixed right in between. We as humans are at the dawn of a new, exciting era of exoplanetary science and discoveries brought about by the extraordinary and accelerating advancements in our technologies. We can see further and deeper in the Universe and our space “eyes” are getting more and more accurate. Of course an extraterrestrial civilization finding our planet (exoplanet to them) could be more or less advanced than we are, so depending on their level of technological sophistication, could just be wondering about us as we do today or have the capability of being able to do more in order to find out if indeed there’s life on Earth or learn of our presence. They might have the technology to easily and quickly analyze Earth or, like us they might be left wondering. There are those that speculate that indeed there might also be a species that already know of our presence; we don’t know. That’s when wide range of possibilities might present themselves. We don’t know how similar this hypothetical species really is to us, neither do we know their history, the history of their evolution, their feelings, emotions, desires. So, the number of variable and possibilities are pretty numerous and complex and the room for speculation is vast.