Swiss play key role in new exoplanet mission

The design for the new Plato satellite ESA

Scientists from the universities of Geneva and Bern are heavily involved in the largest European mission to discover a planet outside of our solar system that orbits a star.

The aim of the research mission is to enable astronomers to discover and characterise planets the size of the Earth, as well as the “super-Earths” that orbit around solar-type stars in their habitable zone.

The European Space Agency (ESA) adopted the mission at a meeting on Tuesday. That means it has green-lighted the solicitation of bids to construct the multi-telescopic satellite, known as Plato, which draws on research in Geneva and Bern. Plato’s mission is to find so-called exoplanets – planets outside our solar system.

Swiss scientists Michel Mayor and Didier Queloz were the first to discover a planet outside our solar system back in 1995, establishing the University of Geneva as a global centre for exoplanet research. The giant planet they found was in a four-day orbit around the nearby star 51 Pegasi. Exoplanet science is now one of the most rapidly growing fields in astronomy.

In 2007, Mayor and fellow astronomer Stéphane Udry discovered the first Earth-sized exoplanet, located 20.5 light years or 120 trillion miles away, with a mass five times that of our planet. It is regarded as a possible candidate for sustaining life.

More recently, an international team that includes researchers from the University of Bern became the first to determine the length of time it takes the last of seven recently discovered exoplanets to orbit around its central dwarf star.

Scientists had already determined the orbital periods for the other six planets in the TRAPPIST-1 solar system, but that of the seventh planet remained unknown. The mystery number, it turns out, is 18.77 Earth days, which was announced in late May by an international team of researchers that spanned some seven countries including Switzerland.

‘Very Important Planets’

Plato’s launch is planned for 2026 following the launches of other satellites Solar Orbiter in late 2018 and Euclid in 2020.

The Plato mission will use a satellite with 26 small telescopes mounted on it to examine one million stars. Researchers hope to find which ones look most like Earth and could possibly sustain life. They also plan to analyse the seismic activity of stars to determine their age, mass and size.

“In a way, Plato will determine VIPs (Very Important Planets) for our future research,” Willy Benz, an astronomy professor at the University of Bern, said in a statementExternal link.

The University of Bern has been designing the mechanical structure to support the 26 telescopes, and Swiss industry will build it. The Italian space agency will take it from there, integrating the telescopes onto the satellite.

The University of Bern already headed up the Swiss space satellite project CHEOPS, (Characterizing Exoplanet Satellite), slated to investigate well-known exoplanets by the end of 2018.

The University of Geneva will handle the follow-up, working to weed out “false planets” such as double stars and determining the masses of planets detected, which helps explain whether it is composed of rock or gas. In these areas, the University of Geneva has been a world leader for more than two decades.