The search is on for a second 'Earth' that humans could colonise and now there's a new candidate - Wolf 1061c.

The rocky orb, more than four times the mass of the Earth, is the closest potentially habitable planet found outside our solar system so far, orbiting a star just 14 light years away.

It is one of three detected by Australian astronomers that orbit a red dwarf star called Wolf 1061.

Scroll down for video

Astronomers have spotted the closest potentially habitable planet found outside our solar system so far, orbiting a star just 14 light years away. Wolf 1061c orbits star Wolf 1061, which is shown in this image in the sky area in the constellation of Ophiucus

'It is a particularly exciting find because all three planets are of low enough mass to be potentially rocky and have a solid surface, 'said lead study author Dr Duncan Wright of the University of New South Wales (UNSW).

'The middle planet, Wolf 1061c, sits within the 'Goldilocks' zone where it might be possible for liquid water - and maybe even life - to exist.

'It is fascinating to look out at the vastness of space and think a star so very close to us - a near neighbour - could host a habitable planet.

While a few other planets have been found that orbit stars closer to us than Wolf 1061, those planets are not considered to be remotely habitable.

This is a simulation of the Wolf 1061 system. Wolf 1061 is an inactive red dwarf star, smaller and cooler than our sun, 14 light years away. The orbits for the planets b, c and d (ordered from the inner planet to the outer) have periods of 4.9 days, 17.9 days and 67.2 days

THE NEARBY SOLAR SYSTEM WITH THREE 'SUPER-EARTHS' In the summer of 2013, astronomers found a nearby solar system packed with up to seven planets including three 'super-Earths' that may be capable of supporting life. The planets orbit Gliese 667C, one of three stars bound together in a triple system 22 light years away in the constellation of Scorpius. Astronomers believe they fill up the star’s habitable zone - the orbital region just the right distance away to permit mild temperatures and liquid water. Three of the new worlds are categorised as 'super-Earths', meaning they have between one and 10 times the mass of the Earth. If, like the Earth, they are rocky and possess atmospheres and watery lakes or oceans, they could conceivably harbour life. Because Gliese 667C is part of a triple system, anyone standing on one of the planets would see three suns in the sky. At night, the two companion stars would be as bright as the full moon on Earth. Advertisement

The three newly detected planets orbit the small, relatively cool and stable star about every five, 18 and 67 days.

Their masses are at least 1.4, 4.3 and 5.2 times that of Earth, respectively.

The larger outer planet falls just outside the outer boundary of the habitable zone, but is also likely to be rocky, while the smaller inner planet is too close to the star to be habitable.

'The close proximity of the planets around Wolf 1061 means there is a good chance these planets may pass across the face of the star,' co-author Dr Rob Wittenmyer added.

'If they do, then it may be possible to study the atmospheres of these planets in future to see whether they would be conducive to life.'

The team made the discovery, which will be published in The Astrophysical Journal Letters, using observations of Wolf 1061 collected by the Harps spectrograph on the European Southern Observatory's 12ft (3.6 metre) telescope in La Silla in Chile.

Small rocky planets like our own are now known to be abundant in our galaxy, and multi-planet systems also appear to be common.

However most of the rocky exoplanets discovered so far are hundreds or thousands of light years away, meaning we have no way of getting to them using current technology.

Last week astronomers from Sweden and Mexico claimed to have discovered two of the most distant objects ever found in our solar system.

One of the objects, they said, could be a 'super Earth' located six times farther away than Pluto, but there's a chance it could also be a brown dwarf - also known as a failed star.

Wolf 1061c joins a select group of planets that may be potentially habitable. One is Gliese 667Cc which lies 22 light years from Earth. An artist's impression of a sunset seen from Gliese 667Cc is shown

It is difficult to tell exactly how far away these objects are, but their speed and brightness suggest that they are unlikely to be stars.

Another exception is Gliese 667Cc which lies 22 light years from Earth. It orbits a red dwarf star every 28 days and is at least 4.5 times as massive as Earth.

Commenting on the discovery of Wolf 1061c, Professor Chris Tinney said: 'Our team has developed a new technique that improves the analysis of the data from this precise, purpose-built, planet-hunting instrument, and we have studied more than a decade's worth of observations of Wolf 1061.'

'These three planets right next door to us join the small but growing ranks of potentially habitable rocky worlds orbiting nearby stars cooler than our sun.'