Our window on the universe shrunk dramatically this week with the demise of two space telescopes 鈥� the European Space Agency鈥檚 planet-spotting COROT and NASA鈥檚 veteran galaxy-hunter, GALEX.
颁翱搁翱罢鈥檚 official termination on 24 June, combined with the apparent shutdown of NASA鈥檚 exoplanet-hunter Kepler, announced in May, represents the end of the first era of space-based alien planet-spotting. Ground telescopes will now carry out all exoplanet searches until 2017, when NASA and ESA will put new instruments into orbit.
Both types of telescope are useful when it comes to characterising exoplanets. Observations from space make it easier to see the faint dips in starlight caused by planets crossing in front of their host stars, and Kepler and COROT both used these to determine exoplanets鈥� sizes. Ground-based telescopes are better at seeing the way a star wobbles under the gravitational pull of its planets, revealing their mass. Together, the results tell us the density of these worlds and so hint at their likely composition.
Advertisement
Glory days
Launched in 2006, COROT found more than 30 confirmed planets, including the first rocky exoplanet, and about 100 planet candidates. Last November, its last working computer developed a fault. Mission managers hoped to bring it back online, but have now given up. Even though COROT lasted twice as long as planned, its loss is keenly felt.
鈥淵ou鈥檙e always disappointed,鈥� says Malcolm Fridlund of the European Space Agency. 鈥淵ou learn so much from a mission like COROT that you always want to extend it.鈥�
The ultraviolet spent the last 10 years gazing at hundreds of millions of galaxies. It discovered a comet-like tail trailing behind the star Mira, and caught a black hole in the act of swallowing a star.
