Feeds

Exoplanets' chemicals may give false-positives for life, boffins say

Methane and Oxygen signatures light years away are no way to spot ET

A new approach to endpoint data protection

Astronomers and exobiologists looking for spectral signatures as indicators of life might be chasing a chimera.

That's the gloomy conclusion of a study published at PNAS, which says inferring the existence of biospheres on exoplanets “might be beyond our reach in the foreseeable future”.

Since all we know about exoplanets is what their light reveals, a lot of work goes into analysing the spectrum of that light. As Science notes, an example of the kinds of chemical brews planet-watchers look for is methane and oxygen, since the only way they could both exist in abundance in the long term is if there are living creatures to renew them both.

While we can't see an exoplanet well enough to spot its plants or microbes, the light those planets reflect will show the presence of such chemicals in its spectrum.

All well and good: but the new study by University of Toronto planetary scientist Hanno Rein tosses a spanner into the search for candidates: if a planet with (for example) oxygen in its atmosphere is circled by a moon with a methane atmosphere, we wouldn't be able to tell the difference.

In fact, in most cases, Rein's study says we probably can't tell whether or not an exoplanet even has a moon. As it's put in the abstract, “Any exoplanet can host a moon that contaminates the planetary spectrum. In general, we will be unable to exclude the existence of a moon.”

“The spectral resolution of even idealised space-based spectrographs that might be achievable in the next several decades is in general insufficient to break the degeneracy,” Rein writes.

And if you're thinking that Rein is taking too hypothetical and speculative a view of things, Science reminds us that light from Earth's oxygen-rich atmosphere would be contaminated to a distant observer if we were circled by Saturn's methane-rich moon Titan.

While an exomoon may have been spotted in the Kepler data, it's not a life-habitable setup: MOA-2011-BLG-262 is about four times Jupiter's size, with a sub-Earth-mass moon. ®

The Essential Guide to IT Transformation

More from The Register

next story
Just TWO climate committee MPs contradict IPCC: The two with SCIENCE degrees
'Greenhouse effect is real, but as for the rest of it ...'
Asteroid's DINO KILLING SPREE just bad luck – boffins
Sauricide WASN'T inevitable, reckon scientists
Brit amateur payload set to complete full circle around PLANET EARTH
Ultralight solar radio tracker in glorious 25,000km almost-space odyssey
Boffins spot weirder quantum capers as neutrons take the high road, spin takes the low
Cheshire cat effect see neutrons and their properties walk different paths
NASA Mars rover FINALLY equals 1973 Soviet benchmark
Yet to surpass ancient Greek one, however
Famous 'Dish' radio telescope to be emptied in budget crisis: CSIRO
Radio astronomy suffering to protect Square Kilometre Array
prev story

Whitepapers

7 Elements of Radically Simple OS Migration
Avoid the typical headaches of OS migration during your next project by learning about 7 elements of radically simple OS migration.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Solving today's distributed Big Data backup challenges
Enable IT efficiency and allow a firm to access and reuse corporate information for competitive advantage, ultimately changing business outcomes.
A new approach to endpoint data protection
What is the best way to ensure comprehensive visibility, management, and control of information on both company-owned and employee-owned devices?