There's been a lot of debate about the claims, especially the latter one, because it's so easy to get bacterial contamination even deep in the ground.
More recently, scientists have resuscitated bacteria that have been on ice for millions of years. The bacteria were in suspended animation in the oldest ice on Earth, in a valley in Antarctica. Those a million or so years old revived relatively easily, and some of the oldest ones, which were covered in ice 8 million years ago, also showed signs of life.
2. The Coldest Places on Earth
Technically there are colder places on Earth than the Arctic and Antarctic, but you'd have to go to a physics lab to find them.
Outside of the lab, nothing is quite so miserable for a warm-blooded creature as a polar winter. In the Antarctic, emperor penguins spend months at temperatures as cold as -40 Fahrenheit, in the dark, without eating, while incubating eggs. How do they manage? They are the definition of misery loving company: they huddle together, sharing warmth and minimizing the surface area of their bodies that is exposed to the cold. They also drop their metabolic rate by about 25 percent and their core temperature by a few degrees.
At the other end of the Earth, a rare duck called a spectacled eider requires open water to feed—which is inconvenient given that most of the Arctic freezes over. Until a few years ago, scientists had no idea where these eiders spent their winters. It turns out they huddle together in cracks between plates of sea ice, diving for clams and sharing their warmth, and possibly churning up their small patch of open water enough to keep it from freezing.
1. In the Stratosphere
Yes, the stratosphere—the layer of Earth's atmosphere that starts at about six miles above the ground. Massive dust storms from the Sahara and other deserts move millions of tons of soil each year, and a shocking number and variety of microbes go along for the ride. Dale Griffin, of the U.S. Geological Survey, has collected microbes in dust at altitudes of up to 60,000 feet (more than 11 miles high).
What's up there? Bacteria, fungi, viruses—hundreds of different kinds. Disturbingly, many of the identified microbes are known human pathogens: Legionella (which causes Legionnaire's disease), Staphylococcus (which causes staph infections), and many microbes that cause lung diseases if (ahem) inhaled.
"I was surprised at the numbers of viable microorganisms that we could find in very small volumes of air when desert dust was present," says Griffin. "If you look, they are there—even in the most extreme environments."