As it orbits Jupiter, the icy surface of Europa heaves and falls with the changing pull of its parent planet’s gravity, creating enough heat to likely support a global ocean beneath the Jovian moon’s solid shell. Experiments by geoscientists suggest that this process, called tidal dissipation, could create far more heat in Europa’s ice than scientists had previously assumed.
When Pluto was reclassified as a dwarf planet in 2006, Neptune regained the title of the solar system’s outermost planet. Since this fascinating gas giant reached opposition on 1 September in the constellation Aquarius, now is a great time to seek it out. We show you how to locate Neptune with binoculars and small telescopes.