CMBR Dipole: Speeding Through the Universe
8.05.2005

Our Earth is not at rest. The Earth moves around the Sun. The Sun orbits the center of the Milky Way Galaxy. The Milky Way Galaxy orbits in the Local Group of Galaxies. The Local Group falls toward the Virgo Cluster of Galaxies.

A Mysterious Streak Above Hawaii
8.02.2005

What in heavens-above was that? Not everything seen on the night sky is understood. The Night Sky Live (NSL) project keeps its global array of continuously updating web cameras (CONCAMs) always watching the night sky.

A Retreating Thunderstorm at Sunset
28.08.2013

What type of cloud is that? This retreating cumulonimbus cloud, more commonly called a thundercloud, is somewhat unusual as it contains the unusual bumpiness of a mammatus cloud on the near end, while simultaneously producing falling rain on the far end.

A Retreating Thunderstorm at Sunset
16.01.2022

What type of cloud is that? This retreating cumulonimbus cloud, more commonly called a thundercloud, is somewhat unusual as it contains the unusual bumpiness of a mammatus cloud on the near end, while simultaneously producing falling rain on the far end.

APOD: 2026 June 20 Б Daytime Moon Meets Evening Star
20.06.2026

Venus is now appearing on the celestial stage as Earth's brilliant evening star, performing with the Moon, other wandering planets, and bright stars in western skies. For evening sky gazers on June 17, the celestial beacon rose after sunset close by a young, slender, crescent Moon.

Nocturnal: Scenes from the Southern Night
6.08.2012

Have you ever seen the night sky change? It does -- sometimes in beautiful and unexpected ways. To see it, though, usually requires patience. The above award winning video shows several of the possible changes in dramatic fashion with a time lapse video.

APOD: 2023 June 26 Б The Belt of Venus over Mount Everest
26.06.2023

You've surely seen it, but you might not have noticed it. During a cloudless twilight, just before sunrise or after sunset, part of the atmosphere above the horizon appears slightly dark and off-color.

Ice Halos by Moonlight and Sunlight
9.01.2026

Both Moon and Sun create beautiful ice halos in planet Earth's sky. In fact, the two brightest celestial beacons are each surrounded by a complex of ice halos in these photos of the sky above Chamonix-Mont-Blanc in France.

Our Rotating Earth
1.07.2020

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.

Mercury Chases the Sunset
12.01.2008

This colorful view of the western sky at sunset features last Wednesday's slender crescent Moon. Of course, when the Moon is in its crescent phase it can never be far from Sun in the sky.