Geostationary Highway through Orion
16.01.2017

Put a satellite in a circular orbit about 42,000 kilometers from the center of the Earth and it will orbit once in 24 hours. Because that matches Earth's rotation period, it is known as a geosynchronous orbit.

Colorful Airglow Bands Surround Milky Way
6.03.2018

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.

Seagull to Sirius
15.12.2016

This broad, beautiful mosaic spans almost 20 degrees across planet Earth's sky. The nebula-rich region lies near the edge of the Orion-Eridanus supperbubble, filled with looping, expanding shells of gas and dust embedded in molecular clouds near the plane of the Milky Way Galaxy.

Markarian s Chain to Messier 64
24.06.2017

Top to bottom, this colorful and broad telescopic mosaic links Markarian's Chain of galaxies across the core of the Virgo Cluster to dusty spiral galaxy Messier 64. Galaxies are scattered through the field of view that spans some 20 full moons across a gorgeous night sky.

Crossing Horizons
25.11.2017

Follow this vertical panoramic view from horizon to horizon and your gaze will sweep through the zenith of a dark night sky over Pic du Midi mountaintop observatory. To make the journey above...

A December Summer Night
23.12.2023

Colours of a serene evening sky are captured in this 8 minute exposure, made near this December's solstice from New Zealand, southern hemisphere, planet Earth. Looking south, star trails form the short concentric arcs around the rotating planet's south celestial pole positioned just off the top of the frame.

APOD: 2024 April 30 Б GK Per: Nova and Planetary Nebula
30.04.2024

The star system GK Per is known to be associated with only two of the three nebulas pictured. At 1500 light years distant, Nova Persei 1901 (GK Persei) was the second closest nova yet recorded. At the very center is a white dwarf star, the surviving core of a former Sun-like star.

Huge Gamma Ray Bubbles Found Around Milky Way
10.11.2010

Did you know that our Milky Way Galaxy has huge bubbles emitting gamma rays from the direction of the galactic center? Neither did anybody. As the data from the Earth-orbiting Fermi satellite began acuminating over the past two years, however, a large and unusual feature toward our Galaxy's center became increasingly evident.

New York Harbor Moonset
6.01.2017

Moonset on January 1 is captured in this sea and night sky snapshot from the port city of New York. Its warm moonlight shining through haze and thin clouds, this New Year's Moon was about 3 days old, in a waxing crescent phase. The visible lunar disk is about 10 percent illuminated.

Nashville Four Planet Skyline
9.02.2001

So far this February, evening skies have been blessed with a glorious Moon and three bright planets; Venus, Jupiter, and Saturn. But just last week, on January 30th, an extreme wide-angle lens allowed astrophotographer Larry Koehn to capture this twilight view of Moon and four planets