Featured Research

from universities, journals, and other organizations

Life possible on extrasolar moons

Date:
January 10, 2013
Source:
Leibniz-Institut für Astrophysik Potsdam (AIP)
Summary:
In their search for habitable worlds, astronomers have started to consider exomoons, or those likely orbiting planets outside the solar system. In a new study, a pair of researchers has found that exomoons are just as likely to support life as exoplanets. 

Artist’s conception of two extrasolar moons orbiting a giant gaseous planet.
Credit: R. Heller, AIP

In their search for habitable worlds, astronomers have started to consider exomoons, or those likely orbiting planets outside the solar system. In a new study, a pair of researchers has found that exomoons are just as likely to support life as exoplanets.

The research, conducted by René Heller of Germany's Leibniz Institute for Astrophysics Potsdam and Rory Barnes of the University of Washington and the NASA Astrobiology Institute, will appear in the January issue of Astrobiology.

About 850 extrasolar planets -- planets outside the solar system -- are known, and most of them are sterile gas giants, similar to Jupiter. Only a few have a solid surface and orbit their host stars in the habitable zone, the circumstellar belt at the right distance to potentially allow liquid surface water and a benign environment.

Heller and Barnes tackled the theoretical question whether such planets could host habitable moons. No such exomoons have yet been discovered but there's no reason to assume they don't exist.

The climatic conditions expected on extrasolar moons will likely differ from those on extrasolar planets because moons are typically tidally locked to their planet. Thus, similar to Earth's moon, one hemisphere permanently faces the planet. Beyond that moons have two sources of light -- that from the star and the planet they orbit -- and are subject to eclipses that could significantly alter their climates, reducing stellar illumination. "An observer standing on the surface of such an exomoon would experience day and night in a totally different way than we do on Earth." explained Heller. "For instance stellar eclipses could lead to sudden total darkness at noon."

Heller and Barnes also identified tidal heating as a criterion for exomoon habitability. This additional energy source is triggered by a moon's distance to its host planet; the closer the moon, the stronger tidal heating. Moons that orbit their planet too closely will undergo strong tidal heating and thus a catastrophic runaway greenhouse effect that would boil away surface water and leave them forever uninhabitable.

They also devised a theoretical model to estimate the minimum distance a moon could be from its host planet and still allow habitability, which they call the "habitable edge." This concept will allow future astronomers to evaluate the habitability of extrasolar moons. "There is a habitable zone for exomoons, it's just a little different than the habitable zone for exoplanets," Barnes said.

The exquisite photometric precision of NASA's Kepler space telescope now makes the detection of a Mars- to Earth-sized extrasolar moon possible, indeed imminent. Launched in 2009, the telescope enabled scientists to reveal thousands of new extrasolar planet candidates. Since 2012 the first dedicated "Hunt for Exomoons with Kepler" is under way.


Story Source:

The above story is based on materials provided by Leibniz-Institut für Astrophysik Potsdam (AIP). Note: Materials may be edited for content and length.


Journal Reference:

  1. R. Heller, R. Barnes. Exomoon habitability constrained by illumination and tidal heating. Astrobiology, 2013; (preprint) [link]

Cite This Page:

Leibniz-Institut für Astrophysik Potsdam (AIP). "Life possible on extrasolar moons." ScienceDaily. ScienceDaily, 10 January 2013. <www.sciencedaily.com/releases/2013/01/130110075354.htm>.
Leibniz-Institut für Astrophysik Potsdam (AIP). (2013, January 10). Life possible on extrasolar moons. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2013/01/130110075354.htm
Leibniz-Institut für Astrophysik Potsdam (AIP). "Life possible on extrasolar moons." ScienceDaily. www.sciencedaily.com/releases/2013/01/130110075354.htm (accessed July 22, 2014).

Share This




More Space & Time News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) — A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) — NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com
Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) — Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, July 18, 2014

This Week @ NASA, July 18, 2014

NASA (July 18, 2014) — Apollo 11 yesterday, Next Giant Leap tomorrow, Science instruments for Europa mission, and more... Video provided by NASA
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins