[1] As the moss banks grow taller, the layers more than an inch below the surface turn brown from lack of sun exposure and eventually become part of the permafrost.

[5] In 2014, terrestrial ecologist Peter Convey and his colleagues from the British Antarctic Survey and the University of Reading discovered that C. aciphyllum remains viable after being frozen for more than 1,500 years.

Samples of the moss were harvested from Signy Island in Antarctica using a coring drill and taken to the University of Reading for analysis.

[3] The 4.5-foot (1.4 m) core was cut into 8-inch (20 cm) sections and exposed to light and temperature levels common to the regions in which the moss grows naturally.

[3] Convey said contamination was not a plausible explanation for the observed growth because only clean saws were used and because C. aciphyllum does not produce spores in the Antarctic region.