Search for extraterrestrial life more difficult than thought

www.seti.org  
Allen Telescope Array
What do mainstream scientists think about the search for ET?  Well, for one thing, it certainly much harder than they or anyone thought it would be - because our current search technology can produce "false positives."

Despite all of our success across a wide field of research, sometimes it's hard to remember that we're still in the early days of our scientific revolution.  We've just begun research on so many different important subjects, and the search for intelligent life in the universe is one.  We still have more to learn on how to search, what a positive result looks like, and then what are we going to do once we get a positive result.

Here's this story with a link to the research in the attribution:
*  *  *  *  *


Search for extraterrestrial life 
more difficult than thought

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.

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 meters 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.

Extraterrestrial Civilizations
Asimov's classic analysis on the
existence of life in the universe


by Isaac Asimov

Click to order from
Powell's Books
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."

Related stories:
Story Source:  Materials provided by University of Toronto, original written by Don Campbell.  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

Comments

Popular posts from this blog

Perfectionism a Major Factor in Suicide

The 2014 Ig Nobel Prizes: The friction of banana skins, Jesus on toast, Baby poop in sausages and more

Here, kitty, kitty, kitty. Humans met sabre-tooth cats 300,000 years ago