Astronomers are convinced that aliens might be residing in the clouds of 'failed brown dwarf stars.'

While these clouds contain enough energy to produce some life forms, the mass is not enough to create a nuclear reaction leading to the formation of a new star, is the explanation.The upper atmosphere of the clouds between the size of a planet and a star is composed of swirling gases. But their temperatures are low - almost as low as the earth's.

Such a star would be conducive for life forms. All life need not live only on terrestrial areas, after all. Lead author of the study Jack Yates, planetary scientist at the University of Edinburgh, told Science: "You don't necessarily need to have a terrestrial planet with a surface."

The team of experts examined a brown dwarf gas cloud called WISE 0855-0714, which is situated only seven light years from the earth. They seemed to base their concept on Carl Sagan's idea of "floating beings" living on the gassy planet, Jupiter. The US scientist, Sagan, had speculated that Jupiter would be inhabited by "enormous balloon-like lifeforms" floating the planet's hot gases.

Said the researchers: "We argue that an atmosphere sitting above a potentially uninhabitable planetary surface may be cool enough to sustain life. By doing this, we define an atmospheric habitable zone (AHZ)."

The clouds contain the ingredients for life that are found on earth, including carbon, hydrogen, nitrogen, and oxygen. However, these life forms might be microbial life forms, after all.

But UK astrobiologist Duncan Forgan from the University of St Andrews, who was not a part of the study, says a number of questions have not been answered.

"Having little microbes that float in and out of a brown dwarf atmosphere is great," he said. "But you've got to get them there first...It really opens up the field in terms of the number of objects that we might then think, well, these are habitable regions."