Featured Research

from universities, journals, and other organizations

Search for extraterrestrial life more difficult than thought

Date:
April 29, 2014
Source:
University of Toronto
Summary:
A new study suggests the search for life on planets outside our solar system may be more difficult than previously thought. The study finds the method used to detect biosignatures on such planets, known as exoplanets, can produce a false positive result.

A new study from the University of Toronto Scarborough suggests the search for life on planets outside our solar system may be more difficult than previously thought.

The study, authored by a team of international researchers led by UTSC Assistant Professor Hanno Rein from the Department of Physical and Environmental Science, finds the method used to detect biosignatures on such planets, known as exoplanets, can produce a false positive result.

The presence of multiple chemicals such as methane and oxygen in an exoplanet's atmosphere is considered an example of a biosignature, or evidence of past or present life. Rein's team discovered that a lifeless planet with a lifeless moon can mimic the same results as a planet with a biosignature.

"You wouldn't be able to distinguish between them because they are so far away that you would see both in one spectrum," says Rein.

The resolution needed to properly identify a genuine biosignature from a false positive would be impossible to obtain even with telescopes available in the foreseeable future, says Rein.

"A telescope would need to be unrealistically large, something one hundred metres in size and it would have to be built in space," he says. "This telescope does not exist, and there are no plans to build one any time soon."

Current methods can estimate the size and temperature of an exoplanet planet in order to determine whether liquid water could exist on the planet's surface, believed to be one of the criteria for a planet hosting the right conditions for life.

While many researchers use modeling to imagine the atmosphere of these planets, they still aren't able to make conclusive observations, says Rein. "We can't get an idea of what the atmosphere is actually like, not with the methods we have at our disposal."

There are 1,774 confirmed exoplanets known to exist, but there could be more than 100 billion planets in the Milky Way Galaxy alone. Despite the results, Rein is optimistic the search for life on planets outside our own is possible if done the right way.

"We should make sure we are looking at the right objects," he says, adding that the search for life within our solar system should remain a priority. He points to the recent discovery of a liquid ocean on Enceladus, one of Saturn's larger moons, as a prime example.

"As for exoplanets we want to broaden the search and study planets around stars that are cooler and fainter than our own Sun. One example is the recently discovered planet Kepler-186f, which is orbiting an M-dwarf star," says Rein.

Rein says locating a planet in a habitable zone while being able to obtain a good resolution to model the atmosphere will help determine what's on the planet.

"There are plenty of reasons to be optimistic that we will find hints of extraterrestrial life within the next few decades, just maybe not on an Earth-like planet around a Sun-like star."


Story Source:

The above story is based on materials provided by University of Toronto. The original article was written by Don Campbell. Note: Materials may be edited for content and length.


Journal Reference:

  1. H. Rein, Y. Fujii, D. S. Spiegel. Some inconvenient truths about biosignatures involving two chemical species on Earth-like exoplanets. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1401816111

Cite This Page:

University of Toronto. "Search for extraterrestrial life more difficult than thought." ScienceDaily. ScienceDaily, 29 April 2014. <www.sciencedaily.com/releases/2014/04/140429185000.htm>.
University of Toronto. (2014, April 29). Search for extraterrestrial life more difficult than thought. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2014/04/140429185000.htm
University of Toronto. "Search for extraterrestrial life more difficult than thought." ScienceDaily. www.sciencedaily.com/releases/2014/04/140429185000.htm (accessed August 22, 2014).

Share This




More Space & Time News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Space to Ground: Hello Georges

Space to Ground: Hello Georges

NASA (Aug. 18, 2014) Europe's ATV-5 delivers new science and the crew tests smart SPHERES. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com
Tiny Satellites, Like The One Tossed From ISS, On The Rise

Tiny Satellites, Like The One Tossed From ISS, On The Rise

Newsy (Aug. 18, 2014) The Chasqui I, hand-delivered into orbit by a Russian cosmonaut, is one of hundreds of small satellites set to go up in the next few years. Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, August 15, 2014

This Week @ NASA, August 15, 2014

NASA (Aug. 15, 2014) Carbon Observatory’s First Data, ATV-5 Delivers Cargo, Cygnus Departs Station and more... Video provided by NASA
Powered by NewsLook.com
Space Shuttle Replica Hoisted for Landmark Exhibit

Space Shuttle Replica Hoisted for Landmark Exhibit

Reuters - US Online Video (Aug. 14, 2014) The space shuttle replica Independence has been hoisted atop Space Center Houston's shuttle carrier aircraft, creating a monument to the shuttle program which will open to the public next year. Rough Cut (no reporter narration). Video provided by Reuters
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