A galaxy settled by traveling planets

The endurance of planets lonely worlds turn around a star, but float alone traveling in space. Far from being an exception, these planets, which may have been expelled from their systems, are very numerous. Researchers from the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), an independent laboratory of Stanford University in Palo Alto, California, believe that, in fact, there are 100,000 for every star that exists in our galaxy. The Milky Way is full.

If observations confirm the estimate, this new class of celestial objects affect the current theories of planet formation and could change our understanding of the origin and abundance of life. "If any of these nomadic planets are large enough to have a dense atmosphere could have trapped the heat enough to cause bacterial life," said Louis Strigari, head of research, published in 'Monthly Notices' of the Royal Astronomical Society. Although nomadic planets do not get the heat of a star, generate themselves through tectonic activity and internal radiation.

The searches in the past two decades have identified more than 500 planets outside our solar system, almost all of which orbit around stars. Last year, researchers found about u na dozen nomadic planets, using a technique called gravitational microlensing, which seeks to stars whose light is momentarily adjusted by the gravity of the planets that pass in front.

Spread the life

The research showed that about two traveling worlds exist for each typical star, called main sequence in our galaxy. The new study is believed that these wanderers may be up to 50,000 times more common. Probably some were expelled from planetary systems, but may not all be formed in this way. A more accurate count, taking into account the smaller objects, has to wait for the next generation of survey telescopes.

A confirmation of this estimate could give returns to another possibility mentioned in the document that as nomads wandering planets through space, collisions could spread microbial life elsewhere.

"Few areas of science have attracted both popular and professional interest in recent times as the prevalence of life in the universe," says study co-author and director of KIPAC Roger Blandford. "The wonderful thing is that now we can begin to address this issue quantitatively by finding more of these planets."