NASA has extended its Kepler space observatory project, announcing that the orbiting telescope will continue its search for alien planets capable of sustaining life until the end of 2016. So far, Kepler has discovered 61 confirmed alien planets - defined as Earth-scale and orbiting stars at a point where liquid water and potentially life could be supported - and flagged up around 2,300 more that could also be contenders; in fact, the project has been described in a NASA review as "an outstanding success."
"Kepler is not only a unique source of exoplanet discoveries," the peer-reviewed assessment concluded, "but also an organizing and rallying point for exoplanet research." The telescope works by taking repeat measurements of changes in brightness of more than 150,000 stars, caused by planets crossing in front of them. The extent to which the brightness changes allows NASA to calculate the size of the planet, and three transits is the minimum to verify that it is indeed a planet and not something else.
"Kepler has revolutionized our understanding of exoplanets and the study of stellar seismology and variability. There is currently no other mission in development that can replace or surpass the precision of Kepler. This extended mission will afford Kepler a unique opportunity to rewrite our understanding of the galaxy and our place in it" Roger Hunter, Kepler project manager, NASA Ames Research Center,
That three-transit requirement means the four year extension could allow Kepler to identify more distant orbits, the speed of light being a limiting factor to notching off that minimum.
Kepler is one of nine astrophysics missions NASA is currently operating, the best known perhaps being Hubble. All nine have been deemed successes, and will continue to be funded at least until the end of 2014.
[via Space; Image credit: NASA/Kepler mission/Wendy Stenzel]