NASA scientists are calling for a new framework in the search for extraterrestial life, and are proposing the creation of a scale that evaluates and combines different lines of evidence that could ultimately prove if we are indeed alone in the universe.
In a new article published in Nature on Wednesday by the agency’s chief scientist, Jim Green, the agency offers a sample scale to use as a starting point for discussions among anyone who would potentially make use of it.
“Having a scale like this will help us understand where we are in terms of the search for life in particular locations, and in terms of the capabilities of missions and technologies that help us in that quest,” Green added.
The scale contains seven levels that NASA said are "reflective of the winding, complicated staircase of steps that would lead to scientists declaring they’ve found life beyond Earth."
The first three levels of the scale will help scientists determine clues of a “signature of life,” ensure that detection was compromised by the instruments contaminated on Earth, and help understand how biological signals are found in an analog environment.
The objective aims at scientists being able to conclude in published studies how their new astrobiology results fit into such a scale in the near future.
“Until now, we have set the public up to think there are only two options: it’s life or it’s not life,” said Mary Voytek, head of NASA’s Astrobiology Program at NASA Headquarters in Washington, DC and the study’s co-author. Voytek added that the agency needed a better way to share the “excitement of each discovery” with the public and other scientists along the journey.
“The search for life beyond Earth requires broad participation from the scientific community and many kinds of observations and experiments. Together, we can be stronger in our efforts to look for hints that we are not alone.”