Nasa’s discovery of Kepler-452b, a planet orbiting around a distant star in deep space, has predictably caused waves of excitement on the internet, with headlines perhaps over-eagerly heralding the existence of a ‘second Earth’.
But beyond the lively tweets about the possibility of having extraterrestrial neighbours, or a brand new planet to set our sights on colonising, the truth is much more mundane. Look a bit closer, in fact, and it seems ‘Earth 2.0’ is actually nothing like our own planet — with some experts even claiming that fireball Venus has more in common with us.
Here are just a few of the key differences between Earth and ‘Earth 2.0’:
Kepler-452b is 60 percent larger than Earth
The planet’s star is around 1.5 billion years older than the Sun
It orbits its star once every 385 days
It has twice the gravitational pull of Earth.
On the surface, it may sound like the discovery of Kepler-452b is something of a revelation, but new planets are being found all the time. Since Nasa launched the Kepler telescope in 2009, it’s identified a total of 4,175 exoplanets — or planets orbiting their own stars — with 500 of those newly found.
However, many of these worlds are either much bigger than Earth or orbit too close to their stars to harbour life. Indeed, astronomers have only found evidence for 13 of these planets being potentially habitable so far. As Greg Laughlin, an astronomer at the University of California, Santa Cruz, told WIRED US: “It’s quite literally anyone’s guess what those planets are like.”
Furthermore, although the new planet may be the most Earth-like found to date, that doesn’t necessarily mean it could harbour ‘intelligent’ life — or any life at all, for that matter. ‘Potentially habitable’ is a rather vague indicator, simply meaning a planet that isn’t too close or far away from its star — but by no means automatically inhabited.
So how will we find out if Earth’s twin is actually out there? Until the launch of the James Webb Space Telescope, set for 2018, which will be powerful enough to detect the atmosphere of some planets within its sights, we may be waiting a while for the answers.