Blue Flash
9.01.2002

Difficult to observe, the momentary green flash above the rising or setting sun has been documented as a phenomenon caused by the atmospheric bending or refraction of sunlight. Like a weak prism, the Earth's atmosphere breaks white sunlight into colors, bending red colors slightly and green and blue colors through increasingly larger angles.

Chilean Skyscape
29.11.2008

Night skies over Chilean mountain top observatories can be dark and clear, with glorious cosmic vistas. In this recent example, the plane of our Milky Way galaxy stretches parallel to the horizon, the galactic center's star clusters, dark dust clouds, and glowing nebulae hovering in the west.

Earthrise
6.09.2015

What's that rising over the edge of the Moon? Earth. About 47 years ago, in December of 1968, the Apollo 8 crew flew from the Earth to the Moon and back again. Frank...

Sputnik Planum vs. Krun Macula
18.06.2016

Pluto's pitted plains meet rugged highlands in this stunning view. On the left lies a southeastern extent of the bright region still informally known as Sputnik Planum. At right the edge of a dark region, informally Krun Macula, rises some 2.5 kilometers above the icy plains.

Starlink Satellite Trails over Brazil
10.12.2019

What are those streaks over the horizon? New Starlink satellites reflecting sunlight. SpaceX launched 60 Starlink communication satellites in May and 60 more in November. These satellites and thousands more are planned by communications companies in the next few years that may make streaks like these relatively common.

APOD: 2025 December 15 Б Gemini Meteors over Snow Capped Mountains
15.12.2025

Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Gemini. That is why the major meteor shower in December is known as the Geminids -- because shower meteors all appear to come from a radiant toward Gemini.

Hyakutake, Venus, Orion, and Pond
18.04.1996

Can you find Comet Hyakutake in the above picture? In this gorgeous photo, the starry night sky of April 9th is pictured with its new comet visitor. In the foreground is a pond with the lights of Kansas City, Missouri on the western horizon. On the upper left, the constellation of Orion is visible.

Gibbous Europa
2.12.2007

Although the phase of this moon might appear familiar, the moon itself might not. In fact, this gibbous phase shows part of Jupiter's moon Europa. The robot spacecraft Galileo captured this image mosaic during its mission orbiting Jupiter from 1995 - 2003.

Zodiacal Light Vs Milky Way
12.02.2009

Two fundamental planes of planet Earth's sky compete for attention in this remarkable wide-angle vista, recorded on January 23rd. Arcing above the horizon and into the night at the left is a beautiful band of Zodiacal Light - sunlight scattered by dust in the solar system's ecliptic plane.

Northern Lights from the Stratosphere
18.01.2024

Northern lights shine in this night skyview from planet Earth's stratosphere, captured on January 15. The single, 5 second exposure was made with a hand-held camera on board an aircraft above Winnipeg, Canada. During the exposure, terrestrial lights below leave colorful trails along the direction of motion of the speeding aircraft.