Dec 6, 2017

The secrets hiding under Europa's ice

Jupiter's icy moon Europa. Photo: NASA / JPL-Caltech / SETI Institute

Europa, the second moon of Jupiter, is encased in a thick crust of ice. Sitting far from the Sun, it's one of the last places you would expect to harbor life. But due to its elliptical orbit around Jupiter — it periodically swings closer and further from the giant planet — the differences in gravity flex and squeeze the core, heating it to molten temperatures.

The end result: Buried under 100 kilometers of rock-hard ice is a globe-spanning liquid water ocean. More liquid water than on the Earth. But is there life?

Why it matters: New simulations suggest the icy shell is broken into segments that shift, flex, and subduct, just like the Earth's crust. Essential nutrients on the surface could then make their way to the ocean, providing a possible pathway for life —permanently locked away from sunlight — to survive.

Go deeper

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 5 p.m. ET: 1,260,104 — Total deaths: 69,082 — Total recoveries: 258,588Map.
  2. U.S.: Total confirmed cases as of 5 p.m. ET: 331,151 — Total deaths: 9.441 — Total recoveries: 16,848Map.
  3. Federal government latest: Surgeon general says this week will be "our Pearl Harbor, our 9/11 moment." The USDA confirms that a Bronx zoo tiger tested positive for coronavirus.
  4. 2020 latest: "We have no contingency plan," Trump said on the 2020 Republican National Convention. Biden says DNC may have to hold virtual convention.
  5. States updates: New York Gov. Andrew Cuomo said the state is "literally going day-to-day" with supplies.
  6. World update: Queen Elizabeth II urges the British people to confront pandemic with "self-discipline" and "resolve" in rare televised address.
  7. What should I do? Pets, moving and personal health. Answers about the virus from Axios expertsWhat to know about social distancingQ&A: Minimizing your coronavirus risk.
  8. Other resources: CDC on how to avoid the virus, what to do if you get it.

Subscribe to Mike Allen's Axios AM to follow our coronavirus coverage each morning from your inbox.

Tiger at Bronx Zoo tests positive for coronavirus

A Malayan tiger cub in its enclosure at the Bronx Zoo on April 27, 2017. Photo: Andrew Lichtenstein/Corbis via Getty Images

A Malayan tiger at the Bronx Zoo has tested positive for the coronavirus, according to statements from the U.S. Department of Agriculture and the Wildlife Conservation Society, which manages the New York City zoo.

Why it matters: It's the first known animal to test positive for the virus in the United States. The tiger is believed to have contracted the virus from an asymptomatic zookeeper.

Go deeperArrow38 mins ago - Health

Boris Johnson admitted to hospital as coronavirus symptoms persist

Photo: Ray Tang/Anadolu Agency via Getty Images

U.K. Prime Minister Boris Johnson has been admitted to the hospital for tests as a "precautionary step" as his coronavirus symptoms have continued to persist 10 days after testing positive, according to a Downing Street spokesperson.

Why it matters: Johnson was the first major elected leader to test positive for the coronavirus. He was admitted to the hospital on the same day that Queen Elizabeth II gave a rare televised address to the nation, urging the British people to confront the pandemic with the same "self-discipline" and "resolve" that has defined the country in times of crisis.

Go deeperArrow2 hours ago - World