Tiny but Tough
For life to exist, temperatures must be moderate, there must be water, and gravity must not be too strong or too weak. Amazingly, there are creatures living right here, right now, that push—and even exceed—those limits. Consider the tardigrade.
Tardigrades, popularly known as water bears, are tiny animals that can survive almost anything: from boiling water to below-zero temperatures, very high radiation, and even the vacuum of outer space. Scientists have been studying them for years.
Water bears may look like bears, but they are really tiny (0.05 millimeters to 1.2 millimeters). They have a barrel-shaped body with four pairs of fat little legs.
You can find water bears almost anywhere, on top of mountains and at the bottom of the sea, from tropical rainforests to the Antarctic. However, they prefer to live a quiet life in normal environments like people’s yards and beaches. They have been on the earth for at least 530 million years.
In extreme conditions, water bears put themselves into a state called “cryptobiosis.” Their basic life functions almost stop, and their body water falls to between one to three percent of normal. They are in a suspended state—neither completely alive nor dead.
While in this suspended state, water bears can survive the most extreme conditions. Scientists have put them in temperatures as low as minus 273 degrees Celsius and as high as 150 degrees. It doesn’t seem to bother them. They can survive in a suspended state for a century and come back to life.
Scientists have not yet found out how and why these wonderful little animals have evolved to be so resilient. How is it possible to live in very high levels of radiation, survive pressure six times that of the deepest ocean, and go through ten days in the vacuum of space? And after being boiled, frozen, and sent into space, water bears can still live for 200 years or more.
For life to exist, temperatures must be moderate, there must be water, and gravity must not be too strong or too weak. Amazingly, there are creatures living right here, right now, that push—and even exceed—those limits. Consider the tardigrade.
Tardigrades, popularly known as water bears, are tiny animals that can survive almost anything: from boiling water to below-zero temperatures, very high radiation, and even the vacuum of outer space. Scientists have been studying them for years.
Water bears may look like bears, but they are really tiny (0.05 millimeters to 1.2 millimeters). They have a barrel-shaped body with four pairs of fat little legs.
You can find water bears almost anywhere, on top of mountains and at the bottom of the sea, from tropical rainforests to the Antarctic. However, they prefer to live a quiet life in normal environments like people’s yards and beaches. They have been on the earth for at least 530 million years.
In extreme conditions, water bears put themselves into a state called “cryptobiosis.” Their basic life functions almost stop, and their body water falls to between one to three percent of normal. They are in a suspended state—neither completely alive nor dead.
While in this suspended state, water bears can survive the most extreme conditions. Scientists have put them in temperatures as low as minus 273 degrees Celsius and as high as 150 degrees. It doesn’t seem to bother them. They can survive in a suspended state for a century and come back to life.
Scientists have not yet found out how and why these wonderful little animals have evolved to be so resilient. How is it possible to live in very high levels of radiation, survive pressure six times that of the deepest ocean, and go through ten days in the vacuum of space? And after being boiled, frozen, and sent into space, water bears can still live for 200 years or more.