Travel a mere 22 light years from Earth and you’ll find a planet that scientists believe is the most likely to be able to host water in its liquid state.
A report to be published in The Astrophysical Journal Letters states that the planet — formally known as GJ 667Cc — circles around a relatively cool star, gets about 90 per cent of the light that the Earth does and has a minimum mass 4.5 times that of the Earth. So just a touch bigger, but that’s not necessarily a problem.
Most of the energy hitting the planet should be infrared, so more of it will be absorbed by the planet according to comments attributed to Professor Chris Tinney of the University of NSW, a member of the research team.
“This means that overall the planet absorbs about the same amount of energy from its star as the Earth absorbs from the Sun: so that would give the planet the right temperature, if it has a rocky surface and a wet atmosphere, to host liquid water. And liquid water is seen as an essential pre-condition for the development of life.”
The same star had previously been observed to host a “Super-Earth”, labelled as GJ 667Cb, but its orbital period is too short to keep the temperature of the planet at a likely temperature to support life.
[The Astrophysical Journal Letters]
Image: Artist impression by Guillem Escudé, Carnegie: (l to r) orbiting planets GJ 667Ca and GJ 667Cb; star GJ667C (centre) and planet GJ 667Cc (foreground)