NASA

Have you ever seen a comet? Tonight — and likely the next few nights — should be a good chance. Go outside just at sunset and look to your northwest. […]

Where do comet tails come from? There are no obvious places on the nuclei of comets from which the jets that create comet tails emanate. One of the best images […]

Comet NEOWISE (C/2020 F3) is now sweeping through northern skies. Its developing tails stretch some six degrees across this telescopic field of view, recorded from Brno, Czech Republic before daybreak […]

Rounding the Sun on July 3rd and currently headed for the outer Solar System, Comet NEOWISE (C/2020 F3) has been growing brighter in the predawn skies of planet Earth. From […]

These silvery blue waves washing over a tree-lined horizon in the eastern French Alps are noctilucent clouds. From high in planet Earth’s mesosphere, they reflect sunlight in this predawn skyscape […]

What is that fuzzy streak extending from Mercury? Long exposures of our Solar System’s innermost planet may reveal something unexpected: a tail. Mercury’s thin atmosphere contains small amounts of sodium […]

A comet has suddenly become visible to the unaided eye. Comet C/2020 F3 (NEOWISE) was discovered in late March and brightened as it reached its closest approach to the Sun, […]

Why would clouds form a hexagon on Saturn? Nobody is sure. Originally discovered during the Voyager flybys of Saturn in the 1980s, nobody has ever seen anything like it anywhere […]