Noctilucent NEOWISE

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 taken on July 8. This summer, the night-shining clouds are...

/ July 9, 2020

Mercurys Sodium Tail

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 that glow when excited by light from the Sun. Sunlight...

/ July 8, 2020

Comet NEOWISE over Lebanon

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, inside the orbit of Mercury, late last week. The interplanetary...

/ July 7, 2020

M43: Dust, Gas, and Stars in the Orion Nebula

Unspeakable beauty and unimaginable bedlam can be found together in the Orion Nebula Arguably the most famous of all astronomy nebulas, the Great Nebula in Orion is an immense interstellar molecular cloud only 1500 light-years away. In the featured deep...

/ July 6, 2020

Saturns Northern Hexagon

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 else in the Solar System. Acquiring its first sunlit views...

/ July 5, 2020

Meeting in the Mesosphere

A sensitive video camera on a summit of the Vosges mountains in France captured these surprising fireworks above a distant horizon on June 26. Generated over intense thunderstorms, this one about 260 kilometers away, the brief and mysterious flashes have...

/ July 4, 2020

Lynds Dark Nebula 1251

Stars are forming in Lynds Dark Nebula (LDN) 1251. About 1,000 light-years away and drifting above the plane of our Milky Way galaxy, the dusty molecular cloud is part of a complex of dark nebulae mapped toward the Cepheus flare...

/ July 3, 2020

The Galaxy, the Planet, and the Apple Tree

The Old Astronomer’s Milky Way arcs through this peaceful northern sky. Against faint, diffuse starlight you can follow dark rifts of interstellar dust clouds stretching from the galaxy’s core. They lead toward bright star Antares at the right, almost due...

/ July 2, 2020

Our Rotating Earth

Has your world ever turned upside-down? It would happen every day if you stay fixed to the stars. Most time-lapse videos of the night sky show the stars and sky moving above a steady Earth. Here, however, the camera has...

/ July 1, 2020

Bright Planetary Nebula NGC 7027 from Hubble

What created this unusual planetary nebula? NGC 7027 is one of the smallest, brightest, and most unusually shaped planetary nebulas known. Given its expansion rate, NGC 7027 first started expanding, as visible from Earth, about 600 years ago. For much...

/ June 30, 2020