The scientists have discovered five extremely ancient alien worlds that are of the size of Venus or even smaller and are therefore rocky in composition.
The scientists claimed that the five newly discovered exoplanets were almost 80 percent as old as our universe, which clearly indicates that these Earth-size planets have been an integral feature of the Milky Way galaxy almost since its beginning.
According to the scientists, the exoplanets circle an 11.2-billion-year-old star, named Kepler-444, which is nearly 25 percent smaller than the sun and lies 117 light-years from our planet Earth.
Kepler-444 and its five known planets were discovered following the analysis of data which were collected by US space agency NASA’s Kepler space telescope.
The scientists say they don’t know much about the composition of the newly-found alien worlds, expect that they have rocky surfaces. They also complete one orbit of Kepler-444 in less than 10 days. This clearly indicates that all the five worlds are almost too hot to support life.
But, the researchers said that the Kepler-444 gave indications of the existence of other age-old planetary systems that are expected to be more hospitable.
Tiago Campante, lead study author and researchers at the University of Birmingham in England, said, “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.”
For perspective, Earth and everything else in our own solar system formed about 4.6 billion years ago.
Study co-author Daniel Huber said, “When asteroseismology emerged nearly 20 years ago, we could only use it on the sun and a few bright stars, but thanks to Kepler, we can now apply the technique to literally thousands of stars.”
Explaining more about Asteroseismology, Huber, who is from the University of Sydney in Australia, said, “It allows us to precisely measure the radius of Kepler-444 and hence the sizes of its planets. For the smallest planet in the Kepler-444 system, which is a bit larger than Mercury, we measured its size with an uncertainty of only 100 kilometers or 62 miles.”
NASA’s Kepler mission was launched in March 2009 at the total cost of USD 600 million to hunt for planets by observing their tiny brightness dips caused while they crossed their host star’s face from the perspective of spacecraft.
The mission aims at helping the scientists in determining how the commonly Earth-like planets occur throughout the Milky Way.
So far, the spacecraft has found over 1,000 exoplanets, with over 3,000 additional exoplanet “candidates” that are awaiting confirmation from the scientists.
The findings of the study were published online in The Astrophysical Journal on January 27 (Tuesday).
