Habitable planets: Model considers possibility of underground life

Sep 10, 2012

A new scientific model to understand the amount of our universe which is habitable developed by University of Aberdeen scientists is being announced today at the British Science Festival.

Vast areas of environment which support life are known to exist in the Earth's subsurface but until now understanding of habitable environments on other planets has only taken into account their surfaces. The new model could vastly increase where we could expect to find life.

Sean McMahon from the University of Aberdeen's School of Geosciences said: "Life 'as we know it' requires . Traditionally, planets have been considered 'habitable' if they are in the 'Goldilocks zone'. They need to be not too close to their sun but also not too far away for liquid water to persist, rather than boiling or freezing, on the surface. However, we now know that many micro-organisms—perhaps half of all living things on Earth—reside deep in the of the planet, not on the surface."

Suns warm planet surfaces but heat also comes from planet interiors. Crust temperature increases with depth so planets that are too cold for liquid water on the surface may be sufficiently warm underground to support life.

Sean McMahon continues: "We have developed a new model to show how 'Goldilocks zones' can be calculated for underground water and hence life. Our model shows that could be much more widespread than previously thought."

Explore further: Exomoons Could Be Abundant Sources Of Habitability

More information:

TERMINOLOGY

An environment is 'habitable' if it is suitable for life as we know it. Habitable environments are not necessarily inhabited.

A 'circumstellar habitable zone' (CHZ or HZ) is a range of distances from a star. Planets that form from Earth-like materials within a star's CHZ are able to maintain liquid water on their surfaces.

CHZs can be thought of as 'Goldilocks Zones' because Earth-like planets orbiting within them are neither too close to the star (too hot) nor too far away (too cold) for water to remain liquid on their surfaces. This concept has been well-established for over 20 years.

We introduce a new term, 'subsurface-habitability zone' (SSHZ) to denote the range of distances from a star within which planets are habitable at any depth below their surfaces up to a certain maximum. (For instance, one might speak of the "SSHZ for 2 km depth", within which planets can support liquid water 2 km or less underground).

add to favorites email to friend print save as pdf

Related Stories

Greenhouse effect could extend habitable zone

Aug 26, 2011

The distant region beyond Saturn is too cold for liquid water, a necessity for life as we know it. But new research indicates that rocky planets far from their parent star could generate enough heat to keep ...

Habitable zones

Aug 22, 2011

(PhysOrg.com) -- The "habitable zone" is the region around a star where a suitable planet could sustain the conditions necessary for life. Most astronomers take it to be the region where the balance between ...

Hot new planet could be in habitable zone -- barely

Sep 12, 2011

Astronomers believe they have found a second planet outside our solar system that seems to be in the right zone for life, just barely. But it would feel like a steam bath - hot, sticky and beyond uncomfortable.

Extending the habitable zone for red dwarf stars

Feb 24, 2012

Scientists have long thought that planets had to orbit very close to small and dim red dwarf stars in order to be warm enough for life. New research challenges that assumption.

Recommended for you

Exomoons Could Be Abundant Sources Of Habitability

18 hours ago

With about 4,000 planet candidates from the Kepler Space Telescope data to analyze so far, astronomers are busy trying to figure out questions about habitability. What size planet could host life? How far ...

Partial solar eclipse over the U.S. on Thursday, Oct. 23

Oct 17, 2014

People in most of the continental United States will be in the shadow of the Moon on Thursday afternoon, Oct. 23, as a partial solar eclipse sweeps across the Earth. For people looking through sun-safe filters, from Los Angeles, ...

A newborn supernova every night

Oct 17, 2014

Thanks to a $9 million grant from the National Science Foundation and matching funds from the Zwicky Transient Facility (ZTF) collaboration, a new camera is being built at Caltech's Palomar Observatory that ...

User comments : 0