How could Aliens detect Life on Earth?
Aliens have all they need to detect life on Earth as it offers a Gaseous Mixture, transmits Radio Signals, and have a network of Satellites.
Humanity has certainly come a long way when it comes to Astronomy. We can explore the farthest reaches of the cosmos through powerful telescopes that are designed specifically for this purpose. The International Space Station in space signifies the achievements of humans. Different probes and rovers are analyzing Mars and other parts of the solar system. Despite all these feats, humanity is curious about one thing: Is there intelligent life anywhere else in the universe?
Scientists from massive space agencies, like NASA and the European Space Agency, have made incredible investments to answer this long-lasting question but all their efforts have failed to give any conclusive evidence. Nearly 4,000 planets have been identified beyond our solar system. The improvement in our astronomical technology might enable us to figure out a planetary oasis, similar to Earth, which hosts animals, plants, and maybe an intelligent civilization. This urge to know more about our planetary neighbors lead us to another intriguing query. Supposing that aliens do exist, how can they find us?
The very first thing that they will need to do is to locate the Earth. The method we adopted to explore a lot of alien planets was to observe the dimming of their host star. Similarly, they can find our planet by seeing the Sun dim as Earth blocks a tiny fraction of its light while orbiting around it. Once they succeed in this, they may look for our atmosphere but inferring anything substantial at such huge distances is extremely hard. Having said that, we are pretty generous in sending out signals, to any outside world, about our existence.
Chemical Mixture of Gases
The fact that Oxygen is present in abundance is a massive sign of life on Earth. The reason for this is its reactivity. As it combines rapidly with other atoms and molecules, finding it in abundance by itself is a complete rarity. The photosynthetic plants act as oxygen factories on Earth as they ensure a continuous supply. However, the presence of O2 is not the only condition and Stephanie Olson, an Astrobiologist at the University of California, seems to agree to that as she said,
“We have discovered several ways in which O2 can accumulate in the absence of life. High levels of O2, or the processes culminating in high levels of O2, may actually preclude the emergence of life on some planets.”
The presence of a chemical mixture of several gases, including Nitrogen, Carbon Dioxide, Methane, and Nitrous Oxide, points in only one direction and that is life.
Satellite Network
The satellites launched in space are also a guide for finding signs of life. An astrophysicist, Hector Socas-Navarro, suggested that intelligent life can be found by using this technique as these metallic bodies will block some starlight in front of or behind the transiting planet once their network is dense enough. According to his estimate, if we continue to leave footprints in space at our present pace, nearby aliens with telescopes as powerful as we have these days will locate our satellites by 2200.
Radio Signals
This could prove to be the easiest way to detect life on Earth as all the aliens need to do is to listen to us. Leakage in radio transmissions is broadcasting our existence to the outside world for the past 100 years. Similarly, humans have intentionally sent messages to the cosmos to engage alien life. In order to detect these radio signals, aliens would have to be within 590 trillion miles of Earth because even the earliest signals have not made more distance than that till now.
Earth’s Surface
A team of astronomers led by Jeff Kuhn and Svetlana Berdyugina proposed a telescope through which the surface of an alien planet can be observed. The telescope will be customized for only one purpose, observing the faint glow of light reflected off an alien planet, and it will need to be at least 130 feet wide. This revolutionary invention called ExoLife Finder (ELF) detects variation in the reflected light to find regional differences in the planets’ terrain. The team is busy with their work and if things go as planned, we will have an ELF within 10 years. Aliens with similar telescopes can literally be a part of life on Earth. About it, Berdyugina said,
“It would be like Star Trek, the reality show. We could virtually visit these planets.”
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