A team of astronomers has discovered a solar system from the dawn of time that contains a star very much like our sun, as well as five planets around the same size as Earth.
After studying data from NASA's Kepler spacecraft, the scientific team from the University of Birmingham, announced their findings today.
Perhaps what's most fascinating is how these scientists discovered this solar system, dubbed Kepler-444. They used asteroseismology, which means they listened to the solar system's star, which gives off pulses of sound. Each pulse represents a change in brightness of the star, which allows researchers to date and measure it.
Finding the planets was easy after that: scientists looked for a change in overall light from the star, signifying that a planet is passing, or transiting, in front of it. This is how Kepler discovers planets. This is also what allows scientists looking at Kepler's data the ability to figure out each planet's size.
"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 Dr. Tiago Campante, from the University of Birmingham's School of Physics and Astronomy. "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.'"
NASA's Kepler spacecraft launched in 2009 with the mission of hunting the skies for exoplanets, or planets outside of our solar system. The mission specifically focuses on finding planets within the habitable zones of their stars, or that place that exists close enough to (but not too far away from) the star where liquid water forms on the planet's surface.
Water, as we know, is one of the key ingredients for sustaining life. So, basically, Kepler looks for planets capable of hosting life on their surfaces.
Unfortunately, a few years ago, two of Kepler's three positioning wheels failed. These wheels keep Kepler pointed in the right direction to collect its data. Instead of giving up, though, NASA engineers cleverly used solar winds to hold the spacecraft steady. Now, Kepler is back to work and finding exoplanets. To date, the mission has confirmed over 1,000 exoplanets.
"We are now getting first glimpses of the variety of Galactic environments conducive to the formation of these small worlds," says Professor Bill Chaplin, from the University of Birmingham's School of Physics and Astronomy. "As a result, the path towards a more complete understanding of early planet formation in the Galaxy is now unfolding before us."
