The Goldilocks Zone: Earth-like Planets Outside our Solar System
The Goldilocks zone, also known as the habitable zone (HZ) is the region around a star in which Earth-like planets may be found.
Find out more about the search for extra-solar planets by following this link!
To be habitable, at least by carbon-based life forms, a planet must contain liquid water on its surface. This only occurs for a narrow range of temperatures. The temperature of a planet is largely determined by its distance from the star that it orbits.
Goldilocks Planets Discovered so Far
HD 85512 b
This exciting new discovery is the best candidate for habitability yet. Discovered in August 2011, this planet, which is 3.6 times the size of Earth, orbits star HD 85512 in the constellation Vela.
This planet is slightly warmer than Earth, at around 30 to 50 degrees Celsius. If it has a suitable atmosphere, with sufficient cloud cover to shield it from the star's harsh rays, it could be a suitable environment for extra-terrestrial life to develop.
Gliese 581 d
Gliese 581 is a red dwarf star located in the Libra constellation, approximately 20 light years from Earth. The planet Gliese 581 d was discovered in 2009 to be in the star's habitable zone. It is located towards the outer edge of the Goldilocks zone, so it may be slightly too cold to provide an environment in which life can thrive. In 2010, astronomers reported the possibility of a second planet located in the middle of this star's habitable zone. However, this has not yet been confirmed.
Links to Related Hubs
Astronomers are excited about the discovery of exoplanets, or extra-solar planets. It is possible that there are planets like Earth orbiting other stars. The Kepler telescope has detected over 1000 exoplanets.
- What is a Dwarf Planet?
In addition to the 8 planets - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune - the solar system also contains several dwarf planets. Find out where they are and why they are so special.