The International Space Station (ISS) has a biodiversity that is similar to what is found in an average home. In spite of being about 408 km from Earth, bacteria seem to be thriving in space.

A new study that started on the ISS has found that not only are bacteria able to survive aboard the ISS, they also actually seem to thrive better in space. The study also found that bacterial colonies inside the station resemble ones that are found in homes, more than microorganisms found living on human bodies.

The study was done by a team of researchers from the University of California and they set out to find out just how many germs are living in the ISS, and determine how the ecosystem in the station is, when compared to an average home. After collecting swab samples from various parts of the station, they were sent down to Earth to be compared with samples taken from homes, according to a report in the Atlantic. Samples were also taken from different spots on the human body.

The results were rather unexpected. The researchers identified 12,554 different species of bacteria from the ISS. Most of them, however, were identified as being harmless. While the composition of the microbes in homes and the station was "significantly different", they matched home surfaces more than human surfaces.

Homes on Earth are exposed to a variety of germs from the environment, but the ISS' only source of germs are the people and things that are physically carried into orbit. "Unlike the ISS, homes on Earth are exposed to a variety of sources of microbes, including the outdoor air, tracked-in soil, plants, pets, and human inhabitants," the study says.

"So 'is it gross?' and 'will you see microbes from space?' are probably the two most common questions we get about this work," said author David Coil, a microbiologist at UC Davis. "As to the first, we are completely surrounded by mostly harmless microbes on Earth, and we see a broadly similar microbial community on the ISS. So it is probably no more or less gross than your living room."

Diversity of germs in the ISS is a positive thing, notes lead author of the study, Jenna Lang. "The diversity was fairly high, indicating that it did not look like a 'sick' microbial community," she explained.

The US study comes just a few days after Russian cosmonauts claimed to have found bacteria that were not there before, on the outside of the ISS, sparking curiosity about alien life.