After decades of broadcasting signals and sending probes to deep space, the human race has still not found evidence that there is life beyond Earth.
That is why, on Wednesday, Oct. 10, astrobiologists convened to reflect on the past few years and figure out a new strategy in the search for extraterrestrial life in the universe. A blue-ribbon panel made up of experts in the field assembled the 196-page report at the behest of Congress.
"If we're really going to achieve a goal as lofty as this, then outside-the-box thinking is really required," stated Barbara Sherwood Lollar, an astrobiologist and chair of the committee.
The Search For Extraterrestrial Life
The report, which was made available online via The National Academies of Sciences, Engineering, and Medicine's The National Academies Press, discusses the extent of the knowledge that scientists, through numerous extensive studies, have acquired in the field of biology, including about life here on Earth.
The report stresses that recent discoveries about organisms that thrive deep under the ocean or beyond the surface and places that the sunlight never touches completely change the way how science look at life and informs new avenues where future missions should search for life on other planets. In particular, it suggests that existence of subsurface life that otherwise might not be detected.
A key challenge that scientists have encountered in the search for life outside of Earth is the detection and interpretation of what is called biosignatures, the chemical or physical markers that indicate the presence of life. Looking for biosignatures of alien life would be a major challenge especially in unfamiliar planets.
"Life doesn't really do anything that chemistry can't do, unless you talk about really complex molecules like drugs and things," explained Sara Walker, another astrobiologist who is not involved in the report. "Life is a system-level property, so you can't really take apart the components and say that the components are indicative of life."
Another point that was discussed in the report was the newly identified exoplanets outside of the Solar System. The Kepler spacecraft that has nearly doubled the number of identified exoplanets since 2015 will enable further exploration in the search for extraterrestrial life.
The planned James Webb Space Telescope, which will be launched in 2021, will study everything about the universe including the formation of solar systems that are capable of supporting life.
The report suggests that NASA should work with privatized companies and space agencies from other nations to succeed in the magnanimous task of finding alien life. Experts also hope that SETI, which searches for signals from extraterrestrial intelligent life rather than single-cell organisms, should also return to mainstream research.