A group of scientists says it has collected an alien bacterium 10 miles above Earth, plus signatures of other extraterrestrial microbes even higher in the atmosphere. The claims were met with immediate skepticism by other scientists. The bacterium was collected 10 miles (16 kilometers) high by balloon operated by the Indian Space Research Organization. Chandra Wickramasinghe, who leads a study into the results, called the microbe a previously unknown strain of bacteria and said it likely came from a comet.