‘Alien Oceans’ argues the search for E.T. should include the outer solar system
A new book explores the evidence that ice-covered moons host hidden oceans of liquid water
![Europa](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2020/03/041120_sp_review_alien-oceans.jpg?fit=1028%2C579&ssl=1)
Europa, which orbits Jupiter, is one of several moons in the outer solar system suspected of having an ice-covered ocean of liquid water.
JPL-Caltech/NASA, SETI Institute