Earth is the lone oceanic planet in the family of the Sun.
Now imagine a planetary system with two of them.
Astronomers may have found just such a system.
And the two water-worlds orbiting there are among the closest analogs of Earth yet found.
The star Kepler 62, about 1200-odd light years away in the constellation Lyra, is like our Sun but smaller and cooler.
So the habitable orbits – where water can be liquid – are closer in.
Each of the two candidate water-worlds could be entirely covered by a global ocean, according to astronomers’ computer models.
Orbiting once every 122 Earth-days, Kepler 62e could be tropical – humid and hot – with a very cloudy atmosphere.
It’s perhaps 60% bigger than Earth.
Further out – in a 267-day orbit – Kepler 62f is about 40% larger than Earth.
And it’s almost surely cooler; in fact, it could be an ice-ball from pole to pole unless it has a lot of carbon dioxide in its atmosphere.
These two share their star with three less hospitable planets, orbiting too close-in; and so too hot for liquid water.
With no land-masses and no chance for fire, it’s hard for us to visualize how any intelligent inhabitants could build a technological society on a totally oceanic world.
But imagine for a moment growing up on a planet from which you could see the lights of cities on another.
Surely that would give you a good reason to build spaceships…
For SPACE.com, I’m Dave Brody
Software and Systems
Not Quite Science
Earth From Orbit
Life Beyond Earth
How it Happens
People and Politics
Spacecraft and La...
Settlement and Colo...
Astronomy and Ast...
Solar System Science
Deep Space Discoveries
Stars and Galaxies
Asteroids and Comets
A planetary system 1200 light years from Earth may contain two worlds entirely covered by global oceans. Kepler 62e and 62f are in the habitable zone of a roughly Sun-like star. Each planet is slightly larger than Earth.
Credit: SPACE.com / NASA Ames Research Center / Kepler Mission