From science-fiction movies to Area 51 myths, it is very apparent that modern society holds a deep interest in what lies beyond the limits of the earth — more specifically, the possibility of life on other planets.
A recent study from the University of Washington has claimed that looking for a chemical disequilibrium that occurs in atmospheres may be key in detecting planets with extraterrestrial life.
While UFO sightings and alien research may seem to be a recent pop-culture phenomenon, the search for extraterrestrial life actually began more than a century ago. In fact, some of the early searches for extraterrestrial life began with the invention of the radio.
In 1896, Nikola Tesla, the inventor of the AC electricity design system, claimed that his wireless electrical transmission system may be used to communicate with aliens on Mars.
In fact, in 1899 he believed he detected a Martian signal, but more recent analysis of his work suggests that the signal might have merely originated from other radios.
In 1924, Mars was in a position where the planet was closer to Earth than any time before. To take advantage of this event and to further the search for alien life, the U.S. developed “National Radio Silence Days,” which was a period of three days in August where radios were kept silent for five minutes every hour with the hope of encountering alien signals.
The radio was used in several other key searches for alien life, most notably Frank Drake’s Project Ozma, where a giant radio telescope was used to detect alien life. This radio telescope later lead to the development of the SETI (Search for Extraterrestrial Intelligence) institute, as well as NASA’s Project Cyclops.
More recently, scientists have gradually started to take a different approach to uncovering life on other planets. An emerging method in the field is to search for biosignatures, which are substances that provide evidence of past or present life on other planets. The first major attempt to do so was in the 1970s, when two probes called the Viking 1 and Viking 2 were sent to Mars in order to uncover signs of metabolism on Mars’ surface.
Now, more than 40 years later, it is well known that the search for atmospheric oxygen is one of the key ways to detect life on other planets.
However, researchers at the University of Washington have begun to question just how reliable this technique may be.
Joshua Krissansen-Totton, a PhD student studying earth and space sciences at the University of Washington (UW), expressed his doubts during a press release.
“We don’t want to put all our eggs in one basket. Even if life is common in the cosmos, we have no idea if it will be life that makes oxygen. The biochemistry of oxygen production is very complex and could be quite rare,” Krissansen-Totton said in a press release.
Krissansen-Totton and other researchers at UW have taken a different approach in uncovering extraterrestrial life. In their study on the history of life on Earth, they have realized that a mixture of gases that are out of equilibrium could most likely only occur with the presence of life. More specifically, they believe the combination of methane and carbon dioxide without carbon monoxide is a key combination to look for in foreign atmospheres when searching for alien life.
Carbon levels in methane and carbon dioxide represent two different levels of oxidation. While carbon dioxide molecules try to hold as many oxygen molecules as possible, methane carbons oftentimes lack oxygen molecules.
“So you’ve got these extreme levels of oxidation. And it’s hard to do that through non-biological processes without also producing carbon monoxide, which is intermediate,” Krissansen-Totton said.
While the researchers still believe that the search for oxygen is a solid way to detect life, they agree that the method may be less effective because the presence of oxygen is less likely to be detected than the combination of the two other gases.
With this, the search for extraterrestrial life continues. While some may be doubtful that humans can find, let alone contact, extraterrestrial life anytime soon, others, such as freshman biomedical engineering major Giang Hoang, are more optimistic.
“Just through mere statistics on the stars and the planets in the universe, the chance of finding life out there is definitely not zero,” Hoang said in an interview with The News-Letter.
Additionally, Hoang expressed her belief that since human beings have already discovered a few planets with roughly the same conditions as Earth, life is most likely existing somewhere out there right now. In the future it may be merely a matter of time, distance and technology that determines whether humans can ever make contact.