Earth-like Exoplanets May Harbor Life: New Telescope Reveals Candidates
Almost 2,000 exoplanets have been discovered to date. But how many of these planets are habitable, and how can we find out? Scientists have taken a closer look and found that with the launch of the James Webb Space Telescope (JWST), we may have our first glimpses into atmospheres of Earth-like exoplanets.
"A planet's atmosphere provides a good guide to likely conditions on the surface," said Joanna Barstow, one of the researchers, in a news release. "The Earth's atmosphere contains significant amounts of nitrogen, oxygen, ozone and water. By contrast, its inhospitable 'evil twin,' Venus, has an atmosphere made mostly of carbon dioxide, which drives its surface temperature to a blistering 450 degrees Celsius."
The JWST is due for launch in 2018. At that point, it was study the universe in infrared wavelengths. In this case, the researchers believe that the JWST may be able to differentiate between a planet with an Earth-like atmosphere and one with more hostile conditions.
"If we took the Earth and Venus, and placed them in orbit around a cool, red star that's not too far away, our study shows that JWST could tell them apart," said Barstow. "Earth's ozone layer, 10 kilometers above the surface, is produced when light from the sun interacts with molecules of oxygen in our atmosphere, and it produces an unmistakable signal that could be detected by JWST. Venus, without a substantial ozone layer, would look different. That's assuming that planets starting out like Earth and Venus would evolve in the same way around a cool star!"
Once the JWST launches, it's possible that researchers could use it to hunt out signs of alien life. It could allow scientists to better target planets for further study.
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