APOD: 2023 December 10 Б Big Dipper over Pyramid Mountain
10.12.2023

When did you first learn to identify this group of stars? Although they are familiar to many people around the world, different cultures have associated this asterism with different icons and folklore. Known...

Panoramic Eclipse Composite with Star Trails
30.08.2017

What was happening in the sky during last week's total solar eclipse? This featured little-planet, all-sky, double time-lapse, digitally-fused composite captured celestial action during both night and day from a single location.

Equinox: The Sun from Solstice to Solstice
23.09.2019

Today is an equinox, a date when day and night are equal. Tomorrow, and every day until the next equinox, the night will be longer than the day in Earth's northern hemisphere, and the day will be longer than the night in Earth's southern hemisphere.

Streak and Plume from SpaceX Crew2 Launch
24.04.2021

What's happening in the sky? The pre-dawn sky first seemed relatively serene yesterday morning over Indian Harbor Beach in Florida, USA. But then it lit up with a rocket launch. Just to the north, NASA's SpaceX Crew-2 Mission blasted into space aboard a powerful Falcon 9 rocket.

Comet Halley vs Comet SWAN
14.05.2020

The pre-dawn hours of May 3rd were moonless as grains of cosmic dust streaked through southern skies above Reunion Island. Swept up as planet Earth plowed through dusty debris streams left behind periodic Comet 1/P Halley, the annual meteor shower is known as the Eta Aquarids.

Rainbow Airglow over the Azores
18.04.2021

Why would the sky glow like a giant repeating rainbow? Airglow. Now air glows all of the time, but it is usually hard to see. A disturbance however -- like an approaching storm -- may cause noticeable rippling in the Earth's atmosphere.

Hale-Bopp: The Great Comet of 1997
8.04.2022

Only twenty-five years ago, Comet Hale-Bopp rounded the Sun and offered a dazzling spectacle in planet Earth's night skies. Digitized from the original astrophoto on 35mm color slide film, this classic image of the Great Comet of 1997 was recorded a few days after its perihelion passage on April 1, 1997.

Messiers and Mars
15.06.2001

A telescopic tour of the constellation Sagittarius offers the many bright clusters and nebulae of dimensioned space in a starscape surrounding the galactic center. This gorgeous color deep-sky photograph visits two such lovely sights, cataloged by the 18th century cosmic tourist Charles Messier as M8 and M20.

Comet Lulin Approaches
2.02.2009

How bright will Comet Lulin become? No one knows for sure. Although it is notoriously difficult to accurately predict the brightness of newly discovered comets, Comet Lulin could well become visible to the unaided eye later this month.

Radio, The Big Ear, and the WOW Signal
2.05.2020

Since the early days of radio and television we have been freely broadcasting signals into space. For some time now, we have been listening too. A large radio telescope at Ohio State University known as affectionately The Big Ear was one of the first listeners.