New telescopes will be able to see whether the atmospheres of other, extremely distant planets contain oxygen. According to New Scientist magazine, the European Extremely Large Telescope (ELT), slated for completion on Cerro Armazones, a Chilean mountaintop within the next decade, will be able to divine whether the gases necessary to support life as we know it are present in a planet's atmosphere.

Current telescopes aren't strong enough to detect atmospheric makeup of anything but big, gaseous planets, called "gas giants." There are two gas giants in our own solar system, Saturn and Jupiter, large planets made of liquids and gases which scientists study by examining the way light passes through their atmospheres.

Ignas Snellen of Leiden Observatory in the Netherlands told New Scientist, "We do this now for Jupiter-sized planets."

Atmospheres on smaller, rocky planets like our own are harder to detect, particularly when current telescopes have difficulty filtering out Earth's own oxygen-rich atmosphere from its observations.

The ELT, however, will be a huge leap forward. It will boast a mirror 39 meters (about 130 feet) across and will be sensitive enough to see some of the furthest known galaxies and star systems in the universe. It will also be able to see beyond Earth's atmosphere because it will be sensitive enough to read whether the air it's observing is rotating with the Earth or with the other planet by way of the atmosphere's wavelength band.

The search promises to be no easy task. A planet will have to pass between its home star and the telescope multiple times for astronomers to gather enough information about it to determine its atmospheric contents. Depending on the shape of its orbit and the size of its star, it could take between four years and four centuries to get the right data.

Exoplanets are planets outside our solar system, and astronomers have identified more than 850 of them as of February, 2013. The presence of oxygen on one of these planets would indicate the possible presence of plants and bacteria in numbers abundant enough to create significant atmospheric oxygen.

Jack O'Malley-James at the University of St. Andrews at Fife, U.K. cautioned, though, that finding oxygen on a planet is not necessarily a guarantee of finding life. He said that organisms on planets with vastly different chemical makeups could find alternatives to oxygen in order to survive. He stressed the need for more detailed chemical analyses of exoplanetary atmospheres.

On Earth, deep sea hydrothermal vents support a variety of anaerobic microbes that thrive in oxygen-free environments. Scientists have observed bacteria at so-called "black smoker" vents that take no energy from sunlight whatsoever, but harvest energy from the sulfur boiling out of fissures in the sea floor where the temperature reaches up to 700 degrees fahrenheit.

O'Malley-James believes that too much emphasis is being placed on the big mirror telescopes. He supports the production of many, smaller "flux bucket" scopes that collect as much light as possible. They're not able to produce the same detailed images as the bigger observatories, but, he said, they allow for the kind of long-term research models needed for observing exoplanets.

"It's good to have a cheaper alternative to the big space-based missions," he said.

[image via Wikipedia]