We have always been hearing about the aliens who exist in the outer world, and who are apparently much more advanced than humans of Earth. But what if someday you get to know that there exists an alien civilization that is possibly 500 years behind the technology and the world that we live in today? It would sure take you to a state of shock. But, it is set of nested questions with numerous ifs and buts.
How Will We Find A Truly Earthlike Planet?
Kepler-452 (middle) is a sunlike star but its key planet is bigger and more massive than Earth.
The astronomers are yet to identify a planet similar to the mother Earth. However, they have come a little close, and apparently found a planet called Kepler 452b, which is roughly five times the mass of Earth and probably belongs to the class of planets called super-Earths. It goes similarly for the Earth-size planets discovered around Trappist-1.
But in order to study these planets, one has to closely look for the shadow that is formed only once in a year, when the planet transits between the star and us.
How Would We Know If A Superficially Earthlike Planet Is Truly Habitable?
This is the plan for NASA’s upcoming FIRST space telescope and its starlight-blocking coronagraph. (Credit: NASA-JPL/G. Blackwood/Noecker et al)
The current method that the researchers are following is to look at the light streaming through the planet’s atmosphere when it passes between us and the star, which is an extremely difficult task. While another way is to directly search for other Earths alongside their stars and then analyze their light, but for that, a powerful telescope will be needed along with an effective way to block the glare of the star. The researchers have some clever ideas to block this external light, such as the chronograph concept, which can be tested by upcoming FIRST telescope.
How Would We Know If There’s Intelligent Life On The Planet?
Representation of Breakthrough Starshot
In order to confirm that there is intelligent life on the planet, the researchers claim that measuring the free oxygen and methane levels could be essential. Also, SETI claims to look for any kind of radio signals, but the possibilities are thin, as they are an ancient civilization, so possibly detecting heavy-metal signatures associated with smelting and other types of simple industry might help.
What Would We Do If We Really Found Rock-solid Evidence Of A Pre-industrial Civilization On A Planet Around Another Star?
To reach out to the alien civilization, getting there personally would not be possible. But, the researchers are working upon interstellar probes that can reach out to the planets and help in further studies. A project called Breakthrough Starshot is exploring the kind of technology needed to do something like that. Assuming a scenario where a potentially Earthlike planet around Alpha Centauri A is found along with, the closest sunlike star the red dwarf Proxima Centauri and we launch interstellar probes there, which arrive in the 2090s. So by 2100, we’re convinced that the planet is inhabited, but what next?
Should We Try To Establish Contact?
For the closest star, communication with the civilians would take around 9 years. Suppose we found a civilization on Kepler 452b, it is 1,400 light years away and each round-trip message would take 2,800 years minimum. Even if we assume for a second that researchers come up with some advanced technology to communicate with the outer world civilians, NASA has a detailed set of planetary protection rules to make sure that humans do not contaminate any habitable planets in the universe.