Gassy Microbes

Some microscopic organisms can live just about anywhere. They can survive extreme temperatures and pressures, total darkness, and environments that are infused with nasty chemicals. Some of them produce methane, which can have a big impact on the climate. And they can tell us a lot about the development of life.

Examples include two species recently found in the Pacific Ocean. They’re types of archaea—descendants of some of the oldest life on Earth.

The research team was led by a marine scientist at the University of Texas. The team examined sediments drilled from hundreds of feet below the sea floor. The deepest sediments were 1.7 million years old. The researchers studied the chemistry of the sediments, and they used genetics technology to suss out the types of organisms.

The archaea survive by eating ancient organic matter in the sediments. They produce methane. In fact, much of the world’s methane has been made by similar organisms.

Methane can form pockets below the ocean floor. The methane can seep out and bubble to the surface. It’s a potent greenhouse gas that traps heat, so once it’s in the atmosphere it can cause major climate changes. Studying these organisms can tell us more about how and where methane is produced, and about possible future climate impacts.

Similar environments might exist on some of the moons in our own solar system. So a better understanding of the archaea on Earth could help us find signs of life on other worlds.