SDO: The Extreme Ultraviolet Sun
23.04.2010

Don't panic, the Sun has not gone wild. But this wild-looking portrait of the nearest star to planet Earth was made on March 30th by the recently launched Solar Dynamics Observatory (SDO). Shown in false-color, the composite view covers extreme ultraviolet wavelengths and traces hot plasma at temperatures approaching 1 million kelvins.

The Flare and the Galaxy
2.09.2015

Is this person throwing a lightning bolt? No. Despite appearances, this person is actually pointing in the direction of a bright Iridium flare, a momentary reflection of sunlight off of a communications satellite in orbit around the Earth.

The Horsehead Nebula
6.10.2019

The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the red emission nebula in the center of the above photograph. The horse-head feature is dark because it is really an opaque dust cloud that lies in front of the bright red emission nebula.

Dark Sky Reflections
29.06.2020

When the lake calmed down, many wonders of the land and sky appeared twice. Perhaps the most dramatic from the dark sky was the central band of our Milky Way Galaxy, visible as a diagonal band. Toward the right were both the Small (SMC) and Large (LMC) Magellanic Clouds, satellite galaxies of our Milky Way.

APOD: 2024 October 9 Б M106: A Spiral Galaxy with a Strange Center
9.10.2024

What's happening at the center of spiral galaxy M106? A swirling disk of stars and gas, M106's appearance is dominated by blue spiral arms and red dust lanes near the nucleus, as shown in the featured image taken from the Kuwaiti desert.

APOD: 2025 September 17 Б Nebulas and Clusters in Sagittarius
17.09.2025

Can you spot famous celestial objects in this image? 18th-century astronomer Charles Messier cataloged only two of them: the bright Lagoon Nebula (M8) at the bottom, and the colorful Trifid Nebula (M20) at the upper right.

APOD: 2026 March 2 Б The Dusty Surroundings of Orion and the Pleiades
2.03.2026

How well do you know the night sky? OK, but how well can you identify famous sky objects in a very deep image? Either way, here is a test: see if you can find some well-known night-sky icons in a deep image filled with filaments of normally faint dust and gas.

Fractal Interstellar Dust Up Close
9.05.1999

Our universe is a very dusty place. Dust usually shows its presence by blocking out light emitted from stars or nebulae behind it, sometimes creating the illusion of a horse's head or a sombrero hat. But nobody really knows what a typical interstellar dust grain looks like. By

Dumbbell Nebula Close Up from Hubble
11.02.2003

What causes unusual knots of gas and dust in planetary nebulas? Seen previously in the Ring Nebula, the Helix Nebula, and the Eskimo Nebula, the knots' existence was not predicted previously and still not well understood.

October Mars
28.10.2005

This October, Mars has become a bright, yellowish star in planet Earth's sky as it approaches oppositon, the period when Mars and Earth pass close as they orbit the Sun. How close is Mars? A mere 70 million kilometers or so, close enough to allow Earth-bound astronomers excellent views of the alluring Red Planet.