DETLEV VAN RAVENSWAAY / SCIENCE PHOTO LIBRARY DETLEV VAN RAVENSWAAY / SCIENCE PHOTO LIBRARY
Stellar habitable zone. Graph showing the habitable zone (white vertical band) for planets in the solar system (horizontal axis) against stellar mass (vertical axis) relative to the Sun (third star up). The unit along the horizontal axis is the radius of the planet's orbit relative to the Earth (positioned at '1'). A star's habitable zone is a narrow region where liquid water could exist to support life. An Earth-like planet that orbits within the habitable zone is sometimes known as a 'Goldilocks planet'.
Model release not available. Property release not required.