New research suggests that Ariel, a moon of Uranus, might have once harbored an ocean about 100 miles (170km) deep. Credit: NASA/JPL-Caltech/PSI/Mikayla Kelley/Peter Buhler Evidence points to a long-lost ocean beneath Ariel’s icy crust. Tides and orbit shifts may have cracked its surface billions of years ago. Growing evidence indicates that a deep ocean may lie hidden beneath the icy exterior of Uranus’ moon Ariel. A new study published in Icarus examined how this subsurface ocean might have formed and evolved, revealing that it could once have reached depths of more than 100 miles (170 kilometers). For comparison, Earth’s Pacific...