French exoplanet mission ends after seven years
BY STEPHEN CLARK
Posted: June 24, 2014
French officials have declared the end of a pioneering science mission after radiation zapped the satellite's instrument, rendering the craft unable to detect the signatures of rocky planets around other stars.
But CoRoT's instrument stopped sending data in November 2012, and months of effort to recover the mission yielded no results.
The French space agency -- CNES -- announced June 18 that CoRoT will be retired from service. The satellite continues to function, and engineers plan a series of technological experiments before switching off the spacecraft.
"Engineering teams at CNES and the French scientific research center CNRS have been unable to recover the instrument," CNES said in a press release. "A series of operations will now be performed to lower CoRoT's orbit and conduct some technology experiments before passivating the satellite. Its journey will end as it burns up on re-entry in Earth's atmosphere."
Built by Thales Alenia Space in France, CoRoT was the first satellite dedicated to searching for planets circling other stars. CoRoT's telescope looked for exoplanets by measuring tiny dips in the brightness of stars caused by a planet passing in front of it.
NASA's Kepler telescope launched in 2009 employs the same transit method for its planet-hunting mission.
According to CNES, CoRoT's extensive data set revealed 32 planets, and astronomers are trying to confirm the existence of 100 more alien worlds -- or exoplanets -- they believe CoRoT detected.
Scientists used follow-up observations with ground-based telescopes to verify CoRoT's discoveries are not false positives. Astronomers can also glean details about a planet's radius, mass, density and orbit.
Circling Earth at an altitude of 550 miles, the spacecraft searched for exoplanets for nearly six years from its launch on a Russian Soyuz rocket in December 2006 until November 2012.
The CoRoT mission was supposed to last two-and-a-half years, but it was twice extended in 2009 and 2012. Officials granted a last extension until 2016 three days before the instrument anomaly on Nov. 2, 2012.
Researchers continue to analyze CoRoT data, and officials say the telescope's archive will complement ongoing and future missions, such as the European Space Agency's Gaia observatory designed to map the Milky Way galaxy with unmatched precision.
CoRoT discovered the first rocky planet beyond the solar system in 2009. The planet, named CoRoT-7b, is located 480 light-years from Earth and orbits its parent star every 20 hours. The planet is nearly five times as massive and 70 percent larger than Earth, leading astronomers to believe its surface is solid.
But CoRoT-7b is so close too close to its star to support life. Temperatures on the day side of the planet may reach 3,600 degrees Fahrenheit, according to astronomers.
Other planets revealed by CoRoT are larger and orbit farther from their parents stars, where conditions might be hospitable for life.
CNES officials say CoRoT was the first telescope to measure the radius of brown dwarfs -- also called failed stars -- which were too small to ignite fusion at their cores.
"CoRoT and ground telescopes also broke new ground through the combined study of stars and their planets, looking at their interactions, tidal effects in stars and the impact of a star's brightness on a planet's structure," said the CNES press release.
The mission also made advancements in the field of astroseismology, the study of a star's internal vibrations, which tells astronomers about its age, structure and composition.
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