Tag: life detection

A Call To Action on Ensuring That Extraordinary Claims About ET Life Come With Extraordinary Evidence

An artist’s rendering of the sweep of cosmic events important to astrobiology.  They include the formation of molecular clouds of gas and dust where stars are born, the subsequent evolving of a protoplanetary disk surrounding the new star, and then the organizing of a cleaned-up solar systems with planets and moons. (National Radio Astronomy Observatory and Dina Clark/University of California, Santa Cruz)

The global scientific search for signs of life beyond Earth has produced cutting-edge and paradigm-shifting science for several decades now, and it has clearly found eager audiences around the world.  This search is a high-priority goal of NASA and other space agencies, as well as institutions, universities and companies.

While the successes in this broadly defined field of astrobiology are legion, the field has also struggled with a problem that flows precisely from its high-impact subject.

That problem is how to best keep its scientific claims evidence based and how to take into account all the myriad factors that can undermine the strength of a “finding.”  And then comes the question of how to best communicate with the public the nature of the findings and all the caveats involved.

There appears to be a widely-held view that some scientific claims and media reports about potential life beyond Earth have become not only a distraction in the field, but have served to undermine some public confidence in the endeavor.

NASA Chief Scientist Jim Green is the lead author of a Nature paper calling for heightened standards for all extraterrestrial life detection science. With discoveries coming in so fast, he said, some formal new standards are needed to increase scientific and public confidence. (NASA /Carla Cioffi)

And some of the leading figures in the field have written a paper, released today by the journal Nature, that calls for the creation of some as yet undefined guardrails or confidence scales to make exciting scientific findings and news about astrobiology more consistently dependable.

The goal is to find ways to make sure that papers meet the widely-embraced Carl Sagan standard that  “extraordinary claims require extraordinary evidence”.

This is how the authors introduce the paper:

“Ours could realistically be the generation to discover evidence of life beyond Earth. With this privileged potential comes responsibility.”

“The magnitude of the question, “are we alone?”, and the public interest therein, opens the possibility that results may be taken to imply more than the observations support, or than the observers intend.… Read more

NASA Panel Supports Life-Detecting Lander for Europa

Artist rendering of a potential life-detecting lander mission to Europa that would follow on the Europa Clipper orbiter mission that is scheduled to launch in the 2020s.. In the background is Jupiter. (NASA/JPL/Caltech)

It has been four long decades since NASA has sent an officially-designated life detection mission into space.  The confused results of the Viking missions to Mars in the mid 1970s were so controversial and contradictory that scientists — or the agency at least — concluded that the knowledge needed to convincingly search for extraterrestrial life wasn’t available yet.

But now, a panel of scientists and engineers brought together by NASA has studied a proposal to send a lander to Jupiter’s moon Europa and, among other tasks, return to the effort of life-detection.

In their recommendation, in fact, the NASA-appointed Science Definition Team said that the primary goal of the mission would be “to search for evidence of life on Europa.”

The other goals are to assess the habitability of Europa by directly analyzing material from the surface, and to characterize the surface and subsurface to support future robotic exploration of Europa and its ocean.

Scientists agree that the evidence is quite strong that Europa, which is slightly smaller than Earth’s
moon, has a global saltwater ocean beneath its deep ice crust, and that it contains twice as much water as exists on Earth.

For the ocean to be liquid there must be substantial sources of heat — from tidal heating based on the shape of its orbits, or from heat emanating from radioactive decay and entering the ocean through hydrothermal vents.  All could potentially provide an environment where life could emerge and survive.

Kevin Hand of the Jet Propulsion Laboratory is a specialist in icy worlds and is deputy project scientist for the Europa project.  He was one of the co-chairs of the Science Definition Team (SDT) and he said the group was ever mindful of the complicated history of the Viking missions.  He said that some people called Viking a “failure” because it did not clearly identify life, but he described that view as “entirely unscientific.”

“It would be misguided to set out to ‘find life’,” he told me.  “The real objective is to test an hypothesis – one we have that if you bring together the conditions for life as we know them, then they might come together and life can inhabit the environment.

“As far as we can tell, Europa has the water, the elements and the energy needed to create a habitable world. … Read more

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