Previous research has shown that there may be as many as 200 billion free-floating planets in our galaxy, the Milky Way. Until now scientists have believed that such "rogue planets", which don't orbit around a star, must have been ejected from existing planetary systems.

New observations of tiny dark clouds in space point out another possibility: that some free-floating planets formed on their own.

A team of astronomers from Sweden and Finland used several telescopes to observe the Rosette Nebula, a huge cloud of gas and dust 4600 light years from Earth in the constellation Monoceros (the Unicorn).