Ice is usually ephemeral; it doesn't last that long before melting. But some ice on our planet has stayed frozen for millions of years, according to scientists on a quest to find the oldest ice.

The medevac involved a network of ships, helicopters and planes spanning thousands of miles on the frigid continent. Australian officials called it "an outstanding success."

Thirty-six people stationed at the General Bernardo O'Higgins Riquelme Antarctic base had tested positive for the virus, Chilean officials said this week.