A little over twenty extrasolar planets have now been discovered that orbit entirely within the habitable zone of their star with a size similar to that of the Earth. But does this mean these worlds are indeed similar to our home planet? UVSPEX is a new instrument being developed at ISAS to fly onboard the Russian-led World Space Observatory. By observing the transit of planets in the ultraviolet, UVSPEX will test a technique to differentiate between rocky planets with an Earth-like or Venus-like atmosphere, pointing the way to finding another habitable world.
Read the full story over on our "Cosmos" blog: Hell and heaven: UVSPEX will test a technique for differentiating between Venus- and Earth-like exoplanets - Cosmos (jaxa.jp)