New study suggests possibility of life billions of years older than humans
An international team of astronomers using the Kepler Space Telescope have discovered a distant solar system that is remarkably similar to our own, but more than seven billion years older. Researchers made observations of the newly discovered system for a period of four years, and determined that Kepler-444 was created close to 11.2 billion years ago.
In a remarkable coincidence, the star that plays host to the system of five small exoplanets — from the size of Mercury to the size of Venus — is also quite similar to our sun.
That said. although Kepler-444 is similar to an ancient version of our solar system, the planets in the system are not believed to be habitable and certainly do not resemble Earth. All of the planets are too far inside the star’s habitable zone at a distance only 10% of that of Earth from the sun.
Statements from researchers
The astronomers on the research team emphasized the implications of discovering a system this ancient. “This system shows that planet formation could take place under very different conditions from the ones in which our solar system was formed and has implications for estimating the total number of planets in our galaxy, and other galaxies,” explained co-investigator Sarbani Basu of Yale University.
“There are far-reaching implications for this discovery,” noted lead author Tiago Campante of the University of Birmingham, U.K. “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.”
Kepler detected system by “transit”
The Kepler Space Telescope located the system of 5 rocky worlds with the transit method, that is, the exoplanets passed in front of their host star, causing its light to dim slightly. This slight dimming can be analyzed to find out the size and orbital characteristics of the transiting planets..
To determine the age of the star, the researchers used asteroseismology to detect the star’s natural resonances caused by sound waves trapped within the star. The resonances result in tiny variations in the star’s brightness that make it possible to measure the star’s size, mass and age.