NASA's prolific Kepler telescope has identified another Earth-like exoplanet, except this one's star is hosting four others like it.

According to the Washington Post, researchers published their findings in the Astrophysical Journal Tuesday. The star has been dubbed Kepler-444 and is some 11.2 billions years old, two-and-a-half years older than Earth.

"This is one of the oldest systems in the galaxy," study co-author Steve Kawaler, an Iowa State University professor of physics and astronomy, said in a press release. "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."

Lead researcher on the study, Tiago Campante, from the University of Birmingham's School of Physics and Astronomy, said Kepler-444 dates back to the start of the Milky Way Galaxy.

"There are far-reaching implications for this discovery. We now know that Earth-sized planets have formed throughout most of the Universe's 13.8 billion year history, which could provide scope for the existence of ancient life in the Galaxy," he said in a press release. "By the time the Earth formed, the planets in this system were already older than our planet is today. This discovery may now help to pinpoint the beginning of what we might call the 'era of planet formation.'"

For their study, the scientists used a method called asteroseismology, which requires careful listening for subtle sound bites and watching for "pulses" in brightness that let them calculate the physical attributes.

"The first discoveries of exoplanets around other Sun-like stars in our Galaxy have fuelled efforts to find other worlds like Earth and other terrestrial planets outside our Solar System," study co-author Bill Chaplin, also from the University of Birmingham's School of Physics and Astronomy, said in the release. "We are now getting first glimpses of the variety of Galactic environments conducive to the formation of these small worlds. As a result, the path towards a more complete understanding of early planet formation in the Galaxy is now unfolding before us."