Sulfurous signs of life
June 30, 2011 By Charles Q. Choi
This chart explains how astronomers measure the signatures of chemicals in the atmospheres of planets that orbit other stars, called exoplanets. Credit: NASA/JPL-Caltech
Any sulfurous molecules that astronomers spot on alien worlds might be a way to reveal whether or not those distant planets host life, researchers suggest.
On Earth, microbes can live off the energy available in sulfurous molecules that volcanoes release, essentially "breathing" these compounds the way humans breathe oxygen. If a similar kind of metabolism evolved on an extrasolar planet, the sulfurous molecules detected in the atmosphere of that world might help reveal the presence of alien life, said researcher Renyu Hu, a doctoral student in planetary science at MIT.
To see what telltale signs any sulfur-dependent life might generate, Hu and his colleagues modeled Earth-sized planets in the habitable zones of sun-like stars -- that is, areas where worlds could have liquid water on their surfaces. These simulated planets possessed nitrogen-based atmospheres like Earth but 1,000 times more sulfur.
Habitable zones for different star types. Our solar system is used for comparison.
Sulfur-dependent life on Earth releases hydrogen sulfide as waste. The researchers found these microbes could increase hydrogen sulfide levels by nearly 10 times what they would be on a planet without such life.From interstellar distances, it would be hard to distinguish hydrogen sulfide (H2S) from water (H2O) on the surfaces of exoplanets. However, the researchers calculate that extra atmospheric hydrogen sulfide would in turn cause more pure sulfur aerosols to form in the air, which astronomers could detect based on their distinctive spectra or fingerprint in the visible and infrared wavelengths.
"Hydrogen sulfide emissions from the surface would have a large impact on the atmospheric composition of a planet," Hu said.
Still, no Earth-sized planets have been discovered yet in the habitable zones of sun-like stars. "Characterization of the atmospheres of exoplanets has been confined to close-in planets so far," Hu said.
Volcanoes on Earth can release huge amounts of hydrogen sulfide and other types of gases into the atmosphere. Credit: USGS
Also, Hu cautioned that hydrogen sulfide is not a conclusive signature of life. "We need to test our assumptions thoroughly," he said. "It may be, for instance, that volcanism could produce tremendous amounts of that gas."Hydrogen sulfide is not the only biosignature gas the researchers are investigating.
"We want to study as many as possible -- look at many, many gases in Earth's atmosphere and see if they can be biosignatures as well," Hu said.
Hu, with his colleagues Sara Seager and William Baines, detailed their findings May 26 at the American Astronomical Society meeting in Boston.
Provided by
Astrobio.net
-
From lemons to lemonade: Reaction uses carbon dioxide to make carbon-based semiconductor,
32 comments
-
Thioridazine kills cancer stem cells in human while avoiding toxic side-effects of conventional cancer treatments,
3 comments
-
SpaceX private rocket blasts off for space station (Update),
42 comments
-
Climate scientists say they have solved riddle of rising sea,
31 comments
-
SpaceX capsule has 'new car' smell, astronauts say (Update),
2 comments
-
revamping general concept and cosmological principle
May 25, 2012
-
Transiting Exoplanet Light Curve
May 25, 2012
-
Math behind Theoretical Physics
May 24, 2012
-
Do we know whats at the center of galaxies yet?
May 23, 2012
-
Structure of the Milky Way?
May 20, 2012
-
What would it take to terraform Pluto and Charon?
May 19, 2012
- More from Physics Forums - General Astronomy
More news stories
SpaceX capsule has 'new car' smell, astronauts say (Update)
SpaceX's Dragon cargo vessel smells like a new car, said astronauts at the International Space Station after opening the hatches Saturday following the spacecraft's landmark mission to the orbiting lab.
Space & Earth / Space Exploration
23 hours ago |
4.5 / 5 (21) |
2
Australia hails surprise super-telescope decision
Australia has hailed a surprise decision giving it a role in a radio telescope project aimed at revolutionising astronomy, vowing to draw on its decades of experience in space science.
23 hours ago |
5 / 5 (4) |
3
Astronomers seize last chance in lifetime for Venus Transit
Astronomers are gearing for one the rarest events in the Solar System: an alignment of Earth, Venus and the Sun that will not be seen for another 105 years.
23 hours ago |
5 / 5 (3) |
2
Astronauts enter world's 1st private supply ship
(AP) -- Space station astronauts floated into the Dragon on Saturday, a day after its heralded arrival as the world's first commercial supply ship.
Space & Earth / Space Exploration
23 hours ago |
5 / 5 (6) |
0
Sophisticated simulations predict future warming
The chances of our planet being hit by a global warming of 3 degrees Celsius by 2050 is as likely as it being hit by an increase of 1.4 degrees, new research shows. Presented in the journal Nature Geoscience, the British study ...
Space & Earth / Earth Sciences
May 22, 2012 |
4.4 / 5 (9) |
51
Nvidia trumpets Tegra 3 phone design wins for 2012
(Phys.org) -- Nvidia’s competitive war paint has a name, Tegra 3. On the heels of Nvidia announcements about lowering costs of its Tegra 3 processors and Nvidia-enabled tablets running Android Ice Cream ...
Browser wars flare in mobile space
The browser wars are heating up again, but this time the fight is for dominance of the mobile Internet.
Scientist: Evolution debate will soon be history
(AP) -- Richard Leakey predicts skepticism over evolution will soon be history. Not that the avowed atheist has any doubts himself.
Dell tablet leak: 10.1-inch display, two-battery choice
(Phys.org) -- Headline after headline talks about vendors’ tablets in the wings as likely number-one contenders for the iPad. Such claims have justifiably been taken with a grain of salt, considering ...
SpotterRF debuts Radar Backpack Kit (w/ Video)
(Phys.org) -- SpotterRF has announced a special radar backpack kit designed to enhance situational awareness for soldiers on the ground. The company says its special radar is designed for warfighters as part ...
Thousands of shellfish found dead in Peru
Thousands of crustaceans were found dead off the coast of Lima following the mystery mass death of dolphins and pelicans, the Peruvian Navy said Friday.
Jun 30, 2011
Rank: 1.7 / 5 (3)
Jun 30, 2011
Rank: 5 / 5 (1)
Jun 30, 2011
Rank: 4.6 / 5 (11)
Ah, Stupid, I forgot. MAN created God as a way to control simple people.
Jun 30, 2011
Rank: 1.3 / 5 (17)
Do you consider scientists like sir Isaac Newton and Blaise Pascal, both of whom were believers in God, to be simple people controlled by clergy? Newton for instance wrote more about scripture than on any other topic. Would you consider your own scientific achievements greater than his?
Jun 30, 2011
Rank: 4.6 / 5 (9)
So? No matter what you say, If life couldn't evolve from nothing, neither could God. Unless we are back to the old 'it's turtles all the way down' fallacy. So where did God come from?
Jun 30, 2011
Rank: 4.5 / 5 (11)
Jun 30, 2011
Rank: 1 / 5 (11)
Hmmm. "Stop hiding those Jews, it's against the Neuremberg laws"...
No seriously, I guess you are sincere. But people can be sincerely wrong you know. I will never stop speaking about my and your Creator, and neither would you if you knew Him. It is a great joy to know the Lord. Be blessed.
Jun 30, 2011
Rank: 5 / 5 (6)
Hello Johonnes,
Curious about the relevance of your comment. The article does not say anything about life springing forth from dead matter.
Besides, we find "new life" all the time in all sorts of places on Earth. Well, new to humans anyways. Why not new life on other planets?
Jun 30, 2011
Rank: 5 / 5 (1)
As for the whole God thing. Newton and Pascal are a little dated, and are really quite irrelevant when looking at the complex scientific issues of today. 300 years is a pretty long time, especially when you take into account how quickly thing have advanced in the last 50, or even 10 years.
Jul 01, 2011
Rank: 5 / 5 (3)
Only problem with that is that there is no bullet proof way of making that determination.
Even if Earth was viewed from lightyears away, there would be no conclusive chemical signature of life. Sure, you could probably detect high oxygen levels and carbon combustion byproducts, but is it bullet proof? No. It is however suggestive, which is the best you can do without actually going there or sending a probe.
Jul 01, 2011
Rank: 1 / 5 (9)
But the whole unstated assumption behind the article is that there is NO creator and by implication therefore, life had to have arisen spontaneously from dead matter.
Sure it would be interesting to find life on some other planet because it would be a very stupendous find with all kinds of theological and scientific implications. But it still wouldn't explain how life arose in the first place. In fact it would create an even bigger mystery as to where life comes from.
Jul 01, 2011
Rank: 5 / 5 (5)
So what?
You can always say God did it,
You could even say God touched those aminoacids some bil years ago (except that it would go against your rid. 6k Earth view)
No prove or disprove possible -> no science
So PLEASE do it somewhere else and take Johannes with you.
You are both really annoying and it seems reporting all those 'God did it, realize it you scumbags' comments dont help either.
On the Subject:
It would be nice if we could find a eath-sized planet in the habitable-zone in the first place. Is it possible to find some with current technology or do we have to wait for the next gen Equipment?
Jul 01, 2011
Rank: not rated yet
Science is about determining reality through testable ideas.
In this light, evolution suggests that life can bloom anywhere in the Universe if the conditions are right.
The alternative and a more realistic interpretation of the Universe is: "God" is an idea of the trigger of the Big Bang which delivered all of the matter and energy in the Universe which could possibly lead to the development of life. In this context, "God" has already "touched" all of the matter, making it "alive". And there is simply no room for interaction with living or non living matter aside thru the natural physical laws.
Jul 03, 2011
Rank: not rated yet
I believe that scientists are going to have to look for a combination of atmospheric signs , not just one or two . If a sulfuric life form is the dominate life form then they will need to look for ALL the gasses that would influence an atmosphere in their proper proportions . Same for all other possible combinations of life and how they would infuence their enviroment as detected from our vantage point . Scientist will need many , many models to guide them by the time they find a potential habitable planet just so they may possibly know what they are looking for . To detect life from here is very complicated and can not be simplified in a couple of paragraphs .
Jul 04, 2011
Rank: not rated yet
Jul 04, 2011
Rank: 1 / 5 (1)
Really? Outdated? Like the laws of motion? Like the laws of ideal gasses? Like integral calculus?
These scientists are not outdated at all. Newtons mechanics helped the Apollo 13 land safely on earth. What is really outdated is the current obsession of science with itsself. Science is becoming a religion. Eventually, religious systems become corrupt.
Jul 04, 2011
Rank: 1 / 5 (5)
No, but the societies that influenced their beliefs are.
It's not, but I'll play along. Why is this a bad thing?
I couldn't agree more. I bet some even start out that way.