Exoplanets and possible habitats

In short: Exoplanets are planets outside our solar system that orbit other stars. Thousands have been discovered so far, some lying in the so-called habitable zone.

In more detail: The habitable zone is the distance range from a star where liquid water could exist on a planet’s surface.

In detail

• Detection methods: The transit method measures tiny dips in brightness when a planet passes in front of its star.
• Radial velocity: Measures the slight “wobble” of a star caused by the gravity of an orbiting planet.
• Habitable zone: Its distance varies greatly depending on the type and size of the star.
• Biosignatures: Astronomers search planetary atmospheres for gases that might indicate life.
• TRAPPIST-1 system: A well-known example with several Earth-like planets around a small star.
• Limits of methods: Direct images of exoplanets are extremely difficult due to the brightness of stars.
• Telescopes: Space telescopes such as James Webb study the atmospheres of distant planets in more detail (schwarze-loecher-und-neutronensterne).