Proposed Indicator of Life On Alien Worlds May Be Bogus

sciencehabit (1205606) writes with bad news for anyone hoping to use the spectral signatures of exoplanets to determine if their atmospheres have life-enabling compositions. "Call it the cosmic version of fool's gold. What was once considered a sure-fire sign of life on distant planets may not be so sure-fire after all, a new study suggests. The signal—a strong chemical imbalance in the planet's atmosphere that could only be generated by thriving ecosystems—could instead be the combined light from a lifeless exoplanet and its equally barren moon."

Comments

statistics

[Charliemopps]

And if we find 3 planets with the signature in the same system? Or we find 100 systems with the signature? How likely is the planet/moon signature? It seems that, it may be proof enough if we find it in the right way.

Any Sufficiently Advanced Tech Still Fallible

[bughunter]

So let's say you're an advanced interstellar civilization looking about for other worlds with life for trade and/or colonization. You have system spanning optics capable of resolving individual planetary systems and resolving the atmospheric spectra thereof. And you find a small yellow star with 8 or 9 planets, including a couple of respectable gas giants and three rocky planets in the habitable zone. Two of those rocky planets clearly have stale atmospheres that have long ago achieved chemical steady state. But the third has an interesting mix of O2, CO2 and CH4, along with multiple other hydrocarbons, all apparently far from a stable state.

But alas, that planet has a HUGE moon... a well-known explanation for the spectra, and the cause of many, many failed planetary exploration missions.

The investment bureacrats HATE uncertainty. If you take a risk and it fails, it will cost your entire clan their wealth and status. You instead decide to commit your finite resources to explore planets with more exploitable natural resources than humongous gas giants and small rocky planets deep within the stellar gravity well.

Re:hmm

[mark-t]

This news says absolutely nothing about the chance of life elsewhere in the universe... it only says something about our chance of being able to detect it as such.