A team of astrophysicists have made an exciting however complex discovery a mere 170 light years away. In their own words, it's "the first evidence of a water-rich rocky planetary body" outside of our own solar system to have evidence of water. It's the "rocky" bit that makes it Earth-like.
Hey, that's pretty exciting! An Earth-like planet covered in water just a few clicks across the galaxy—what a day! Well, it's a little more complicated than that. Scientists didn't actually find the planet itself but rather "its shattered remains." The debris used to be a tiny planet composed of 26 percent water, but about 200 million years ago, the star that it was orbiting—creatively named GD 61—started to die. Before becoming a white dwarf, GD 61 devoured the water-covered planet and any other bodies in the system.
So you're not going swimming in the GD 61 system anytime soon (or ever). However, we now know that it's possible for water to exist on Earth-like planets outside of our solar system. It was previously believed that Earth's water might have come from the dwarf planet Ceres which orbits our Sun near the asteroid belt. That would've meant that water is not unique to Earth but might be a phenomenon that's unique to our solar system. Not so, we now know.
This is just one of a string of exciting discoveries in the past year or so suggesting that the temperate, water-covered rock we call Earth (and home) is not so one-of-a-kind. Last December, scientists spotted Tau Ceti, an Earth-like and possibly habitable planet just 12 light years away. Then, a few months later, they found two more some 1,200 light years that they identified as the two exoplanets most perfect for life. And around the same time, researchers said that there could be as many as 100 billion of these Earth-like planets in the Milky Way Galaxy alone!
That's a lot of Earth-like planets, but we won't know if they're habitable until we know. And it's going to take time and lots of little discoveries like the remains GD 61's once water-covered planet. Until then, Mars is looking better and better.
Image copyright Mark A. Garlick, space-art.co.uk, University of Warwick and University of Cambridge