NASA's Kepler space telescope revolutionized the study of alien worlds after launching in 2009, and a number of other missions now stand poised to carry the burgeoning field into the future.
Over the next decade, NASA and the European Space Agency (ESA) aim to launch a handful of spacecraft that should discover thousands of additionalexoplanets and characterize some of the most promising — the most apparently Earthlike — new finds in detail.
These future missions are all following in the footsteps of Kepler, whose observations have revealed that the Milky Way galaxy is jam-packed with alien planets. The instrument has spotted more than 3,500 planet candidates to date.
Kepler's original planet-hunting activities came to an end this past May when the second of its four orientation-maintaining reaction wheels failed, robbing the spacecraft of its ultra-precise pointing ability. But the instrument may continue its planet search in a modified and limited fashion, as part of a possible future mission dubbed K2.
NASA is expected to make a final decision about K2, and Kepler's ultimate fate, around the middle of next year. By then, the first member of the exoplanet new wave will already be aloft — Europe's Gaia mission.
Gaia will head to a gravitationally stable spot about 900,000 miles (1.5 million kilometers) from Earth called the sun-Earth Lagrange Point 2. Over the next five years, the spacecraft will repeatedly measure the position, movement and brightness changes of more than 1 billion Milky Way stars — about 1 percent of the galaxy's total.
"This huge stellar census will provide the data needed to tackle an enormous range of important problems related to the origin, structure and evolutionary history of our galaxy," ESA officials write in a description of the Gaia mission.