Three Earth-like planets in neighboring solar system

By Casey Frye, CCNN Writer

gliese 667 habitable earth 2
An artist’s impression of one of the planets in the Gliese 667 star system.

Did you know that during the daytime, there is a star so big and bright, you can’t even look at it directly? It’s true. It also happens to be the only star in our solar system! It’s called… the Sun!

Yes, the Sun is a star, and Earth is just one of the eight planets that goes around it. On a clear night, you can’t see the Sun, but what you can see instead, are millions of billions of trillions of other stars sprinkled across the vast dark sky.

Surely one of those stars has to have a planet like Earth… and you’d be right to think so! Past discoveries have found other Earth-like planets floating around stars, but a recent sighting has given researchers even more motivation to find them.

First, let’s talk about what makes Earth so special and why scientists aren’t as interested in finding planets like Mercury or Uranus. See, Earth is at a perfect distance from the Sun, in a range called the “habitable zone” that allows water to remain in a liquid state. If it were any closer to the Sun, like Mercury, the temperature would be too sizzling hot, and water would evaporate. If it were any farther away, like Uranus, the temperature would be too shivering cold and water would freeze.

Now, researchers from the University of Hertfordshire’s Centre for Astrophysics Research, have spotted a star called Gliese 667C, with six planets orbiting around it. That’s only two less planets than we have in our own solar system, but what’s even more fascinating, is that three of the six planets are orbiting in the habitable zone! No more than one Earth-like planet has ever been discovered in the habitable zone before, so three possible Earths is big news.

“This is the first time that three such planets have been spotted orbiting in this zone in the same system,” said astronomer Paul Butler, with the Carnegie Institution in Washington, D.C.

Compared to other stars in the universe, Gliese 667C is not that far. Scientists estimate it’s only 22 light years, or 129 trillion miles, away. Just thinking about the distance from Los Angeles to New York , which is around 2,500 miles, hurts my head. I don’t want to think about how far 129 trillion miles is! Still though, on a universe level, it’s not that far at all.

Scientists are more encouraged than ever to continue searching for other planets in the habitable zone now that they’ve found 3 in one place! After all, where there is water, there could be life, and where there is life, there could be other intelligent beings. Perhaps they too are looking at our Sun, remarking to themselves that our Earth-like planet is in the habitable zone.

Images courtesy of European Southern Observatory.

habitable worlds