Researchers discovered an 11.2-billion-year-old star that is host to at least five Earth-like planets.
The findings could have implications for life in the universe well before our own existence, Iowa State University reported.
"We thus show that Earth-size planets have formed throughout most of the Universe's 13.8-billion-year history, leaving open the possibility for the existence of ancient life in the Galaxy," the astronomers wrote in their paper.
The Sun in question is called Kepler-444, and is 25 percent smaller than our sun and is 117 light years from Earth. The planets orbiting the Sun are between the sizes of Mercury and Venus, but orbit too close to their host to be habitable.
To determine the size of the foreign star, the researchers measured sound waves within the star. The sound waves influenced the star's temperature, leading to pulsating changes in brightness that gave away the star's size and age. The findings were made using NASA's Kepler spacecraft, which has the ability to take high precision measurements of changes in brightness.
"This is one of the oldest systems in the galaxy," Kawaler said, noting that our sun is 4.5 billion years old. "Kepler-444 came from the first generation of stars. This system tells us that planets were forming around stars nearly 7 billion years before our own solar system. Planetary systems around stars have been a common feature of our galaxy for a long, long time."
The researchers hope the new findings will provide insight into the mysterious history of our galaxy, the Milky Way.
"From the first rocky exoplanets to the discovery of an Earth-size planet orbiting another star in its habitable zone, we are now getting first glimpses of the variety of Galactic environments conducive to the formation of these small worlds," the astronomers wrote.. "As a result, the path toward a more complete understanding of early planet formation in the Galaxy starts unfolding before us."
The findings were published in a recent edition of the Astrophysical Journal.
