The hunt for alien life heats up as NASA releases a guide on how to spot and recognize extraterrestrial life in space.
Now that astronomers have found thousands of rocky worlds in and outside of the galaxy, it's time to begin searching for life.
"We're moving from theorizing about life elsewhere in our galaxy to a robust science that will eventually give us the answer we seek to that profound question: Are we alone?" Martin Still, NASA exoplanet scientist, says in a statement.
NExSS Identifies Biosignatures
NASA-led Nexus for Exoplanet System Science or NExSS, composed of leading researchers from various sciences, have released what is essentially a guide to searching for alien life in six papers in the journal Astrobiology.
In these papers, scientists outline the most promising signs of life or biosignatures. The different teams also considered the best way to recognize and analyze biosignatures in exoplanets, then identified the instruments necessary to find potential life.
"We have to be open to the possibility that life may arise in many contexts in a galaxy with so many diverse worlds — perhaps with purple-colored life instead of the familiar green-dominated life forms on Earth, for example," coauthor Mary Parenteau from NASA's Ames Research Center in Silicon Valley points out. "That's why we are considering a broad range of biosignatures."
Parenteau and the other NExSS scientists explain that it's important to look at a range of different traits when determining whether a planet and its sun is capable of cultivating life.
Breaking Down The Different Factors
According to Gizmodo, the first of the six new papers published discusses the different biosignatures that scientists need to keep an eye out for, specifically two signal types: atmospheric gases and light.
Light, after all, is the only way scientists can look for life at present. Telescopes are used to observe light in far-flung worlds, from the types of gases in their atmosphere to potential colors that could be suggestive of life.
The second paper outlines potential false positives and false negatives, including the ways a planet could contain oxygen without life, while the third paper analyzed Earth's process of developing life and how the same processes could exist in other planets.
In the fourth paper of the series, NExSS created a framework that can quantify a planet's likelihood to contain life, based on the available evidence such as the atmosphere, oceans and continents, and climate.
The fifth and sixth papers focused on evaluating current capabilities of the scientific community in finding alien life, as well as proposing future moves that will help the mission.
New Paper Refutes Alien Existence
NASA's papers come hot on the heels of research by Oxford University that stressed the likelihood of aliens simply not existing in the observable universe.
However, the renowned scientists involved in the study tell Universe Today that although their paper shows that life outside Earth is improbable given current scientific knowledge, it also will not be surprising if there are other intelligent species out there.