David Ehrenreich



I’m studying sunsets on distant planets around other stars, hoping to find traces of life in their atmospheres.

Extrasolar sunsets can only be observed when the planet is transiting across the stellar disc, as seen from the Earth.

When sunlight passes through the atmospheric limb of the Earth, it is absorbed and scattered by gas, dust, and clouds, producing a coloured vista such as the one pictured above (a sunset on Earth as seen from the International Space Station). My research work focuses on observing and modelling such colours for "sunsets" on planets revolving around other stars, also known as exoplanets.  Measuring their colours with spectroscopy is a powerful way to determine the atmospheric properties of these alien worlds, which is my main research interest.

I am currently working on the CHEOPS satellite project, Europe’s next exoplanet mission. CHEOPS will follow-up the most interesting exoplanets in the sky in search for their transit, performing first-step characterisation of these remote worlds (are they gaseous, icy, or rocky planets?). It will also provide golden targets for future large telescopes with powerful spectrographs able to probe the atmospheres of these planets.

I am also collaborating to the Swiss National Centre for Competencies in Research called PlanetS for the exoplanetary atmosphere characterisation project. More information are available on the team website: www.exoplanets.ch.

Image credits:
NASA/Expedition 15/ISS; D. Ehrenreich


Senior Research Associate at the University of Geneva