Neptune's Rotation Determined

Planetary scientists have accurately determined the rotational speed of Neptune for the first time, discovering one of the greatest improvements in measuring this planetary attribute of gas giants in over 350 years.

Comet Impact on Neptune

Distribution of carbon monoxide and other indicators detected in the atmosphere of Neptune by the Herschel satellite indicate a comet impacted the planet about two hundred years ago, evidence largely learned after observation of Comet Shoemaker-Levy impacting Jupiter in 1994.