New European space telescope will study ‘super-Earth’ exoplanets

Artist’s conception of Cheops. Credit: University of Bern / ESA

An amazingly wide variety of exoplanets are now being discovered orbiting other stars and some of the most interesting are those referred to as “super-Earths,” rocky worlds which are typically a little larger to a few times bigger than Earth.

The Kepler space telescope and other observatories have provided our first glimpse of these planets, but astronomers are anxious to be able to study them in more detail, especially those which may be potentially habitable.

If all goes as planned, that opportunity will come in 2017, when a new small space telescope is launched by the European Space Agency (ESA) called CHaracterising ExOPlanets Satellite (Cheops). Cheops is designed to specifically examine already-discovered exoplanets; it will focus on planets ranging from super-Earths to Neptune-sized as announced by ESA on October 19.

According to Professor Alvaro Giménez-Cañete, ESA Director of Science and Robotic Exploration, “By concentrating on specific known exoplanet host stars, Cheops will enable scientists to conduct comparative studies of planets down to the mass of Earth with a precision that simply cannot be achieved from the ground.”

Cheops will be able to accurately measure a planet’s radius. When a planet’s mass is also known, it will also determine the density, which can provide clues to the planet’s internal structure. Cheops can also determine which planets have significant atmospheres, an important criteria for assessing a planet’s possible habitability.

Cheops’ finding will also help to identify the best targets for other future space telescopes such as the ground-based European Extremely Large Telescope and the James Webb Space Telescope, which can further analyze exoplanet atmospheres.

Cheops and its successors will help to answer some of the biggest questions – only dreamed of not too long ago – about whether there are other Earth-like planets out there and if any of them are also inhabited, an exciting possibility indeed.

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