CMBR Dipole: Speeding Through the Universe
6.09.2009

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.

Night of the Perseids
14.08.2010

On the night of August 12, from moonset until dawn was a good time to see meteors. Enthusiasts watched as comet dust rained on planet Earth, streaking through dark skies during the annual Perseid Meteor Shower.

December s Comet Wirtanen
6.12.2018

Coming close in mid-December, Comet 46P Wirtanen hangs in this starry sky over the bell tower of a Romanesque church. In the constructed vertical panorama, a series of digital exposures capture its greenish coma on December 3 from Sant Llorenc de la Muga, Girona, Catalonia, Spain, planet Earth.

APOD: 2024 September 23 Б Comet Tsuchinshan ATLAS Approaches
22.09.2024

What will happen as this already bright comet approaches? Optimistic predictions have Comet C/2023 A3 (TsuchinshanБATLAS) briefly becoming easily visible to the unaided eye -- although the future brightness of comets are notoriously hard to predict, and this comet may even break up in warming sunlight.

Orbiting a Black Hole
1.07.2013

What would it look like to orbit a black hole? Since the strong gravity of the black hole can significantly alter light paths, conditions would indeed look strange. For one thing, the entire sky would be visible, since even stars behind the black hole would have their light bent to the observer's eye.

7,000 Stars And The Milky Way
12.02.1996

This panorama view of the sky is really a drawing. It was made in the 1940s under the supervision of astronomer Knut Lundmark at the Lund Observatory in Sweden. To create the picture, draftsmen...

Red Aurora Over Australia
28.01.2017

Why would the sky glow red? Aurora. A solar storm in 2012, emanating mostly from active sunspot region 1402, showered particles on the Earth that excited oxygen atoms high in the Earth's atmosphere. As the excited element's electrons fell back to their ground state, they emitted a red glow.

APOD: 2024 January 31 Б Camera Orion Rising
30.01.2024

What does Orion rising look like to a camera? During this time of the year, the famous constellation is visible to the southeast just after sunset. From most Earthly locations, Orion's familiar star pattern, highlighted by the three-stars-in-a-row belt stars, rises sideways.

Zodiacal Light
26.08.1997

Sometimes the sky itself seems to glow. Usually, this means you are seeing a cloud reflecting sunlight or moonlight. If the glow appears as a faint band of light running across the whole sky, you are probably seeing the combined light from the billions of stars that compose our Milky Way Galaxy.

Crepuscular Rays Over Lake Michigan
11.08.2010

What could cause such rays of dark? Dark sky rays were caught in spectacular fashion earlier last month from Pentwater, Michigan, USA, looking west over Lake Michigan. The cause is something surprisingly familiar: shadows. Clouds near the horizon can block sunlight from reflecting off air, making columns outward from the Sun appear unusually dark.