In a groundbreaking discovery, NASA’s Kepler Space Telescope has identified an Earth-like planet, Kepler-186f, within the habitable zone, also known as the “Goldilocks zone,” of a neighboring star in the Cygnus constellation, approximately 500 light-years away. This marks the first time an Earth-sized planet has been found within the habitable zone of another star.

What’s even more exciting is the presence of four additional planets orbiting the star in the Kepler-186f system. If the neighboring star is similar to our Sun, the chances of life on Kepler-186f skyrocket.

“We are only aware of one planet where life thrives – Earth. In our quest to find life beyond our solar system, we focus on finding planets with features similar to our home planet,” explains Elisa Quintana, a research scientist at the SETI Institute and lead author of the paper published in Science. “The discovery of an Earth-sized habitable zone planet is a major breakthrough.”

The star in the Kepler-186f system has half the mass and size of our Sun and receives only a third of the energy that we receive from our Sun. Kepler-186f completes one orbit around its star in 130 days.

This discovery adds to the estimated 40 billion Earth-sized planets thought to exist in our Milky Way galaxy and is a tantalizing hint at the possibility of finding life beyond our solar system.