New Conditions for Life on Other Planets

Tides can render the so-called "habitable zone" around low-mass stars uninhabitable. This is the main result of a recently published study by a team of astronomers led by René Heller of the Astrophysical Institute Potsdam (AIP).

Extrasolar planets, or exoplanets for short, have been known to exist outside our solar system since 1995. When searching for life in outer space, scientists focus on those exoplanets that are located in the habitable zone. This means that they orbit their sun at a distance where the temperatures on the planet's surface allow for the presence of liquid water. Water is believed to be an essential ingredient for life. Until now, the two main drivers thought to determine a planet's temperature were the distance to the central star and the composition of the planet's atmosphere. By studying the tides caused by low-mass stars on their potential earth-like companions, Heller and his colleagues have concluded that tidal effects modify the traditional concept of the habitable zone.