European astronomers announced Tuesday that they have discovered the first planet beyond our solar system that orbits in a "sweet spot" zone where life could exist.
The planet, about five times as massive as Earth, orbits Gliese 581, a red dwarf star about 20 light years from our solar system.
The team of Swiss, French and Portuguese scientists who found the planet estimate its surface temperature ranges from freezing to 104 degrees Fahrenheit, the crucial range in which water can exist as a liquid.