Saturn and Six Moons
6.07.2021

How many moons does Saturn have? So far 82 have been confirmed, the smallest being only a fraction of a kilometer across. Six of its largest satellites can be seen here in a composite...

APOD: 2024 June 12 Б Aurora over Karkonosze Mountains
12.06.2024

It was the first time ever. At least, the first time this photographer had ever seen aurora from his home mountains. And what a spectacular aurora it was. The Karkonosze Mountains in Poland are usually too far south to see any auroras.

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.

Three Nebulae in Narrow Band
2.11.2007

Narrow band filters and a false-color palette give these three nebulae a stunning appearance against the cosmic canvas of the central Milky Way. All three are stellar nurseries about 5,000 light-years or so distant, toward the nebula rich constellation Sagittarius.

IC 4406: A Seemingly Square Nebula
27.07.2008

How can a round star make a square nebula? This conundrum comes to light when studying planetary nebulae like IC 4406. Evidence indicates that IC 4406 is likely a hollow cylinder, with its square appearance the result of our vantage point in viewing the cylinder from the side.

Eclipse Pair
3.01.2025

Eclipses tend to come in pairs. Twice a year, during an eclipse season that lasts about 34 days, Sun, Moon, and Earth can nearly align. Then the full and new phases of the Moon, separated by just over 14 days, create a lunar and a solar eclipse.

Nebulas Surrounding Wolf Rayet Binary BAT99 49
21.04.2004

How could two young stars power these colorful interstellar gas clouds? Although hidden by thick dust, the stars spew forceful ions and energetic radiation that cause the clouds to fragment and light up.

NGC 6888: The Crescent Nebula
13.08.2008

NGC 6888, also known as the Crescent Nebula, is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star. This beautiful telescopic view combines a composite color image with narrow band data that isolates light from hydrogen and oxygen atoms in the wind-blown nebula.

X Ray Jet From Centaurus A
28.10.1999

Spanning over 25,000 light-years, comparable to the distance from the Sun to the center of our own Milky Way galaxy, a cosmic jet seen in X-rays blasts from the center of Centaurus A. Only 10 million light-years away, Centaurus A is a giant elliptical galaxy - the closest active galaxy to Earth.

Comet Garradd and Messier 15
6.08.2011

Recorded on August 2, this telescopic composite image catches Comet Garradd (C/2009 P1) in the same field of view as globular star cluster M15. The celestial scene would have been a rewarding one for influential 18th century comet hunter Charles Messier.