Astronomers may be closer to finding us a new home if Earth goes belly up in a few hundred years..
NASA's Spitzer Space Telescope has discovered seven Earth-sized planets orbiting around a single star about 40 light years away.
Three of the planets are located in the habitable zone, also known as the Goldilocks Zone (not too hot, not too cold, just right), a place that has good conditions to find liquid water on a planet's surface, raising the prospect of life.
The next step is to scan the planets' atmosphere for possible chemical fingerprints of life.
"This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, associate administrator of the agency’s Science Mission Directorate in Washington.
"Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”
Even if the planets do not have life now, it could evolve. TRAPPIST-1 is at least 500 million years old, but has an estimated lifespan of 10 trillion years. The sun, by comparison, is about halfway through its estimated 10-billion-year life.