Even though we have not found any evidence of extraterrestrial life so far, that's not to say we shouldn't be prepared for the day when that could change.
While we are yet to turn up a whisper of hard evidence to support the hypothetical existence of life beyond Earth, we are nonetheless always looking for it.
If or when we ever do find that evidence, though – or even just begin
to piece together the first, incremental traces of it – we need to be
ready, NASA scientists say.
In a new scientific commentary –
led by none other than the space agency's chief scientist, James Green –
NASA researchers make the case for why we need to establish a framework
for reporting evidence of extraterrestrial life.
"Our generation could realistically be the one to discover evidence of life beyond Earth," the team writes. "With this privileged potential comes responsibility."
According to the researchers, the discovery of alien life by humanity is unlikely to be a yes-or-no, all-or-nothing event.
it's more probable that the detection of extraterrestrial life will be a
drawn-out, evolving process of scientific investigation and discovery –
and the sooner that's understood by everybody, the better.
includes many claims of life detection that later proved incorrect or
ambiguous when considered in exclusively binary terms," the researchers explain.
instead, we recast the search for life as a progressive endeavor, we
convey the value of observations that are contextual or suggestive but
not definitive and emphasize that false starts and dead ends are an
expected part of a healthy scientific process."
is the complexity of this kind of multi-tiered, qualitative assessment,
that we need a progressive scale to measure and chart new discoveries –
something much like the technology readiness level (TRL)
scale that NASA itself uses to track the progress of spaceflight
instruments, all the way from concept to implementation in actual
In the context of astrobiological detections of life, NASA says we could use an analogue: a "confidence of life detection" (CoLD)
scale, with the lowest levels of the scale focusing on the initial
identification of potential biosignatures, with higher levels reserved
for more specific and certain measurements of the subject.
a nuanced scale – tracking potential life detections against a series
of objective, progressively more demanding benchmarks – would help place
all purported biosignatures in a standardized context, helping the
research community (and the broader community following their work) to
interpret whatever new findings scientists report.
best practices for communicating about life detection can serve to set
reasonable expectations on the early stages of a hugely challenging
endeavor, attach value to incremental steps along the path, and build
public trust by making clear that false starts and dead ends are an
expected and potentially productive part of the scientific process," the researchers write.
the outcome of the dialogue, what matters is that it occurs… In doing
so, we can only become more effective at communicating the results of
our work, and the wonder associated with it."
The perspective has been published in Nature.