Here's how Europe's exoplanet hunter will unravel the mystery of extraterrestrial life

Friday, 20 Dec, 2019

Cheops, an acronym for Characterizing Exoplanet Satellite, a joint endeavor of 11 member states of the European Space Agency (ESA), will observe the bright stars that are already known to be orbited by planets.

The satellite, part of an ESA programme to study planets and stars outside the solar system, had been within 90 minutes of launching from Kourou in French Guiana when the problem came up, said Arianespace. It was the second attempt after Tuesday's first launch try was delayed.

- When will Cheops launch, and how can I watch it?

The satellite will be launched into an unusual pole-to-pole orbit about 500 miles above Earth. It has a Ritchey-Chrétien telescope, which is the same design used in the Hubble and Spitzer space telescopes.

Dr Nicholas Walton, a CHEOPS board member and the institute's lead on the project, told the Cambrige Independent in an interview past year: "CHEOPS only has a small field of view but will point at a star only when we know that an exoplanet will be transiting".

The CHEOPS satellite was one of a few payloads carried into space by the Soyuz rocket on Wednesday.

On Tuesday, the launcher's automated sequence was interrupted during the final countdown at 1 hr 25 mins, owing to what was described as "an anomaly" in the launch setup.

Cheops arrives at the launch pad.

Didier Queloz, 2019 Nobel Physics Prize victor, told AFP in French Guiana, "Cheops is 710 kilometers (440 miles) away, exactly where we wanted it to be, it's absolutely ideal". Dr. Queloz will probably be in attendance at the launch.

Rather than look for more planets, Cheops will study some that have already been discovered in order to understand them better.

Missions like Kepler and TESS have pinpointed many potential exoplanets, but we rarely get more than their location, approximate mass, and orbital characteristics.

Like other space telescopes, CHEOPS will watch for tiny dips in stars' brightness that are caused by planets passing in front of them - called transits. In 2012 the ESA selected CHEOPS, based on that initial design, as its first small-class (or S-class) mission, a type of smaller-scale program meant to promote innovation and education.

The analysis technique, developed by Princeton University astronomer Tim Morton and colleagues, analyzed which changes in the amount of light are due to planets transiting and which are due to stars or other objects.

Artist impression of Cheops, the Characterising Exoplanet Satellite, with an exoplanet system in the background.

While the discoveries made by Cheops will be exciting in their own right, they will also be valuable for those selecting targets for the next generation of flagship observatories, such as the James Webb Space Telescope.