Closest 'habitable' exoplanet discovered
As the hunt for a 'second Earth' continues, exoplanet hunters from New South Wales have discovered a new candidate: the closest to our Solar System ever observed.
This artist's concept illustrates a young, red dwarf star surrounded by three planets. Image Creidt: NASA/JPL
Astronomers from the University of New South Wales say they have discovered the closest potentially habitable planet outside our Solar System that we know of.
The planet is over four times the mass of Earth and was found orbiting a star called Wolf 1061, 14 lightyears away.
It is one of three orbiting the star and is in the ‘habitable zone’, meaning it is close enough to sustain liquid water and potentially life.
The three planets orbit the star roughly every five, 18 and 67 days.
Their masses are at least 1.4, 4.3 and 5.2 times that of Earth, respectively.
The largest of the three is orbiting too far from the star, while the smallest is too close.
The middle-sized planet is in the ‘Goldilocks’ zone, meaning it is just close enough to its star for life to potentially be supported. For more on this, read our guide What makes a planet habitable?
“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,” says the study’s author Dr Duncan Wright.
“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.”
A simulation of the orbits of planets around Wolf 1061, one of which is thought to have the potential to sustain liquid water and possibly life. The simulation is running at approximately one day per second. Credit: This simulation was made using the Universe Sandbox 2 software from universesandbox.com
The discovery was made using the HARPS spectrograph on ESO’s 3.6m telescope in La Silla in Chile.
“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,” says Professor Chris Tinney, head of the group Exoplanetary Science at UNSW.
“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.”
“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,” says team member Dr Rob Wittenmyer.
“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.”