Future projects of the European Space Agency ESA

ESA's three Voyage 2050 themes

The LIFE project, led by ETH Zurich and supported by the NCCR “PlanetS”, explores climatically moderate exoplanets – planets outside our solar system with Earth-like temperatures that could contain liquid water in their atmosphere or on their surface. The researchers are looking for Earth-like exoplanets in the infrared light, an area of research that lies within ESA's external page Voyage 2050 theme: From Temperate Exoplanets to the Milky Way. This article summarise thier research efforts.

Possible applications of the ORIGIN instrument, which is being developed within the framework of the NCCR “PlanetS” at the University of Bern, include exploration of the icy moons of Jupiter and Saturn. The question of whether life can be discovered under the icy cover of the icy moons also falls within one of ESA's three thematic fields: Moons of the giant planets. You can find out more external page here. The NCCR “PlanetS” was already pursuing these two projects with concrete plans and sub-projects before ESA's choice of topic. The third topic chosen by ESA is: New physical probes of the early Universe.

LIFE: Earth-like exoplanets in infrared light

Characterizing planets many light years away is already a difficult task. But climatically moderate rocky planets pose a particular challenge because they are relatively small and orbit their stars at great distances. This makes it difficult to study them through the common transit method, which involves analysing the light from the star as it passes through the planet's atmosphere and interacts with the molecules present. These interactions leave traces in the starlight and thus provide information about the planet's atmosphere. But the smaller a planet and the further away it is from its star, the smaller the chance of detecting such a transit. Many molecules associated with life – such as water, oxygen or methane – also interact with infrared light, which is strongly emitted by planets. To find signs of life on distant planets, it is therefore necessary to look for these molecules at infrared wavelengths.

Goal of the LIFE telescope

“However, infrared light is much more difficult to detect than the bright light of a star,” explains Adrian Glauser, lead instrument scientist of the LIFE project at ETH Zurich and member of “PlanetS”. A direct detection of faint planetary emissions requires a large telescope situated in space. It is the only feasible way to detect the very faint light of planets outside our solar system.

“Unfortunately, a telescope the size of ESO's Extremely Large Telescope ELT with its 39-meter mirror, which is currently being built in Chile, does not fit into a rocket,” explains the acting head of the LIFE mission, ETH professor and member of “PlanetS” Sascha Quanz with a laugh. “That's why the LIFE mission will send a swarm of five smaller telescopes into space, flying in formation and optically connected by a centerpiece. This will give us an effective mirror size of up to 200 meters and enable us to detect the very faint infrared light from planets”.

Huge opportunities

Although the task is daunting, the project is still at an early stage and the timetable requires perseverance, Glauser is not shying away from it. “I am ready to dedicate the rest of my career to this project,” he says. Sascha Quanz, who proposed the project as one of ESA's Voyage 2050 themes, adds: “The selection of the theme is of course exciting news for the LIFE initiative and an additional incentive for our activities!”

Andreas Riedo and Niels Ligterink, who are conducting research at the University of Bern on the development of the most sensitive instrument for the search for life: The ORganics Information Gathering Instrument, or ORIGIN, are just as pleased. Details about this project can be found external page here. ESA's choice of themes are set, but which specific projects ESA will be implementing in the future has not yet been decided. Thieir unveiling is being followed with anticipation across Europe.