Ancient star with Earth-sized planets dates to 'dawn of the galaxy'

NASA's Kepler mission helps locate a solar system stocked with Earth-sized planets that dates back 11.2 billion years.

Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
Amanda Kooser
2 min read

An artist's interpretation of Kepler-444. Tiago Campante/Peter Devine

Our solar system has an ancient doppelganger located 117 light years away.

Researchers working with data from NASA's Kepler Space Telescope have found a star that formed 11.2 billion years ago. The star, Kepler-444, is quite a relic, considering that scientists estimate the universe to be 13.8 billion years old.

The star's age also makes it the oldest-known system hosting Earth-sized planets. Kepler-444 hosts five planets in a range of sizes between Mercury and Venus, making the largest planet a bit smaller than Earth. The star itself is smaller and cooler than our sun. The findings were published this week in The Astrophysical Journal.

A team led by scientists at the University of Birmingham in the UK made this discovery using asteroseismology, a process described as "listening to the natural resonances of the host star which are caused by sound trapped within it." The information can be used to determine mass, age and diameter. Planet sizes were noted by studying the dimming of the light from the star as the planets crossed it.

"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," says lead researcher Tiago Campante from the University of Birmingham.

Our solar system is about 4.5 billion years old, a youngster compared to Kepler-444. Though it's impossible to tell if Kepler's planets are capable of sustaining life, we do know they would have gotten a considerable head-start on us if any of them have habitable environments.