The planet Mercury is being pelted regularly by bits of dust from an ancient comet, a new study has concluded. Comet Encke has the shortest period of any comet, returning to perihelion every 3.3 years. The dust from the comet affects Mercury’s tenuous atmosphere and may lead to a new understanding on how these airless bodies maintain their ethereal envelopes.
A global ocean lies beneath the icy crust of Saturn’s geologically active moon Enceladus, according to new research using data from NASA’s Cassini mission. Researchers found the magnitude of the moon’s very slight wobble, as it orbits Saturn, can only be accounted for if its outer ice shell is not frozen solid to its interior, meaning a global ocean must be present.
A pockmarked, icy landscape looms beneath NASA’s Cassini spacecraft in new images of Saturn’s moon Dione taken during the mission’s last close approach to the small, frozen world. Two of the new images show the surface of Dione at the best resolution ever. Cassini passed 295 miles (474 kilometres) above Dione’s surface at 7:33pm BST on 17 August 2015.