A Sun Halo over Utah
11.04.2006

Have you ever seen a halo around the Sun? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.

NGC 7331 and Beyond
27.07.2006

Spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog.

Yukon Aurora with Star Trails
11.03.2010

Fixed to a tripod, a camera can record graceful trails traced by stars as planet Earth rotates on its axis. But at high latitudes during March and April, it can also capture an aurora shimmering in the night.

Sunspot Loops in Ultraviolet
10.04.2011

It was a quiet day on the Sun. The above image shows, however, that even during off days the Sun's surface is a busy place. Shown in ultraviolet light, the relatively cool dark regions have temperatures of thousands of degrees Celsius.

A Wide Field Image of the Galactic Center
6.01.2012

From Sagittarius to Scorpius, the central Milky Way is a truly beautiful part of planet Earth's night sky. The gorgeous region is captured in this wide field image spanning about 30 degrees.

Sunspot Loops in Ultraviolet
26.01.2014

It was a quiet day on the Sun. The above image shows, however, that even during off days the Sun's surface is a busy place. Shown in ultraviolet light, the relatively cool dark regions have temperatures of thousands of degrees Celsius.

Milky Way above Atacama Salt Lagoon
16.09.2014

Galaxies, stars, and a serene reflecting pool combine to create this memorable land and skyscape. The featured panorama is a 12-image mosaic taken last month from the Salar de Atacama salt flat in northern Chile. The calm water is Laguna Cejar, a salty lagoon featuring a large central sinkhole.

Auroral Corona over Norway
14.10.2014

Higher than the highest mountain lies the realm of the aurora. Auroras rarely reach below 60 kilometers, and can range up to 1000 kilometers. Aurora light results from energetic electrons and protons striking atoms and molecules in the Earth's atmosphere.

In the Center of Spiral Galaxy NGC 5033
9.01.2017

What's happening in the center of spiral NGC 5033? Many things -- some circular, some energetic, and some not well understood. NGC 5033 is known as a Seyfert galaxy because of the great activity seen in its nucleus.

APOD: 2023 November 5 Б Creature Aurora Over Norway
5.11.2023

It was Halloween and the sky looked like a creature. Exactly which creature, the astrophotographer was unsure (but possibly you can suggest one). Exactly what caused this eerie apparition in 2013 was sure: one of the best auroral displays that year. This spectacular aurora had an unusually high degree of detail.