People love a good story about aliens, from strange sightings to government cover-ups. Scientists have been trying for decades to answer the question of whether life exists in space. Still, the reality is that we don’t have enough technology to find life in space.
Astrobiology is the discipline that studies life beyond our planet. Scientists look for three elements to detect life: water, carbon dioxide, and hydrogen.
To find out if a planet has liquid water, it must be a certain distance from its star and not too close to the Sun. For example, scientists have found 59 planets in the Golden Ratio Zone. Still, to know if a planet has life, it must have biosignatures.
In 1977, astronomers noticed a strange signal from space, which they called “Wow,” and it is believed that if life is evolving on a planet and getting to the point where it can communicate, build things and create technology like humans, then signs of it can be detected.
If we could detect an alien intelligence, we would probably never be able to communicate with alien life because it is hundreds of millions of light-years away.
In December 2021, the largest and most powerful space telescope ever built, the James Webb Space Telescope will be launched into orbit to detect life molecules such as oxygen. By the end of the decade, there will be huge ground-based telescopes with lenses 40 meters wide.
Three ground-based telescopes with 25- to 40-meter-wide mirrors are expected to be operational in the 2020s. In the late 2030s, two proposed Nasa spacecraft will visit Europa in 2023 to see if it has the potential to support life.
NASA’s budget for 2022 is the largest since the 1960s, and astrobiology really came of age in the 2020s. Most scientists are confident that we will find signs of life in our corner of the galaxy.
Meet the scientists trying to speak alien
An entire field of science is dedicated to making contact with alien civilizations. So, for example, we can use intentional messages to let them know we want to make contact.
Seth Shostak is a senior astronomer at SETI, the Search for Extraterrestrial Intelligence Institute. He believes that if alien civilisations are anything like us, they’ll emit plenty of signals all the time, and we can eavesdrop on one of them to make contact.
SETI uses 42 radio telescopes to search for signals from extraterrestrial civilizations. They are looking for signals that are electromagnetic signals, such as flashing lights or radio waves, and they know that these signals could go from one star system to another.
There is no official protocol for when we receive alien signals. Still, there is a very simple one that tells us what to do in case we pick up a signal that looks promising. We should send them lots of information, like video games and TikTok dances.
Some say you shouldn’t reply to any signal we might pick up. Still, some people think we should be actively sending signals to potential alien habitats to try to elicit first contact.
We can use radio waves to send signals to nearby stars. We think that by sending intentional messages to the nearest star to Earth, we’ll let the civilizations know that we want to make contact. In some cases, that may just be what’s required to get a response.