The advances in space-based observatories are tantalizing and, with the launch of JWST and other advanced direct imaging telescopes (such as the "star shade" concept), we could start studying small habitable worlds with atmospheres and teasing hints as to any biosignatures within the next couple of decades.
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But to fully investigate this exciting class of exoplanet, "we require the ability to directly image exoplanets orbiting 1,000 or more of the nearest sun-like stars." Such an endeavor would require a huge space-borne observatory - an optical telescope with a diameter exceeding 10 meters. Considering the Hubble Space Telescope is only 2.4 meters in diameter, the exoplanetary atmosphere telescopes of the future will require some huge innovative leaps before they become a reality.
One thing seems certain, however. The longer we gaze into the stars, the more certain we become about the possibility for life beyond Earth.
"Our own Galaxy has 100 billion stars, and our Universe has upwards of 100 billion galaxies - making the chance for life elsewhere seem inevitable based on sheer probability," writes Seager. "We can say with certainty that, for the first time in human history, we are finally on the verge of being able to search for signs of life beyond our solar system around the nearest hundreds of stars."