UNIVERSITY PARK, Pa., May 26 (UPI) -- Penn State University scientists said Wednesday they have found millions of micro-microbes surviving in a 120,000-year-old ice sample.
The sample was taken from more than 10,000 feet below the surface of the Greenland glacier.
The scientists say the discovery may help define the limits for life on Earth and elsewhere in the universe, such as on cold planets similar to Mars.
Researchers Vanya Miteva and Jean Brenchley said the majority of the microbes they discovered were less than 1 micron in size -- smaller than most commonly known bacteria, which range from 1 to 10 microns. In addition, a large portion of the cells appeared to be even smaller and passed through filters with 0.2-micron pores.
The scientists want to know how microbial life can be preserved in polar ice sheets for hundreds of thousands of years under stresses that include subzero temperatures, desiccation, high pressures, and low oxygen and nutrient concentrations.
The scientists say because the ice was mixed with the ancient permafrost at the bottom of the glacier, the microbes could have been trapped there for perhaps millions of years.
