In the Center of Saturns North Polar Vortex
4.12.2012

What's happening at the north pole of Saturn? A vortex of strange and complex swirling clouds. The center of this vortex was imaged in unprecedented detail last week by the robotic Cassini spacecraft orbiting Saturn. These clouds lie at the center of the unusual hexagonal cloud system that surrounds the north pole of Saturn.

Ripples Through a Dark Sky
30.07.2016

Sunlight ripples through a dark sky on this Swedish summer midnight as noctilucent or night shining clouds seem to imitate the river below. In fact, the seasonal clouds often appear at high latitudes in corresponding summer months. Also known as polar mesospheric clouds, they form as water vapor is driven into the cold upper atmosphere.

Diamond Ring and Shadow Bands
21.11.2012

As the total phase of last week's solar eclipse came to an end, sunlight streaming past the edge of the Moon created the fleeting appearance of a glistening diamond ring in the sky.

Orion s Horsehead Nebula
21.02.2008

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 seen just below and left of center in the this photograph. The brightest star on the left is located in the belt of the familiar constellation Orion.

NGC 7635: The Bubble Nebula Expanding
5.02.2018

It's the bubble versus the cloud. NGC 7635, the Bubble Nebula, is being pushed out by the stellar wind of massive star BD+602522, visible in blue toward the right, inside the nebula. Next door, though, lives a giant molecular cloud, visible to the far right in red.

Reflecting Merope
6.12.2000

In the famous Pleiades star cluster, a star's light is slowly destroying a passing cloud of gas and dust. The star, Merope, lies just off the upper right edge of this recently released picture by the Hubble Space Telescope.

APOD: 2026 September 15 Б A Daytime Eclipse: Moon Occults Venus
15.09.2026

There was something behind the clouds. Upon close inspection, it was the Moon, which was hard to see yesterday around noon above the small village of Cessy, France. But soon, it was not only the Moon. As expected, a bright dot suddenly appeared from behind the Moon -- the planet Venus far in the distance.

Stars, Dust, and Gas Near Antares
26.01.2022

Why is the sky near Antares and Rho Ophiuchi so dusty yet colorful? The colors result from a mixture of objects and processes. Fine dust -- illuminated from the front by starlight -- produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae.

Tharsis Volcanos
18.06.1999

Ice crystal clouds float above the immense Tharsis volcanos of Mars in this recently released picture from NASA's Mars Global Surveyor spacecraft. Olympus Mons at the upper left is 340 miles across and almost 15 miles high - the largest volcano in the solar system.

Orions Horsehead Nebula
21.03.2005

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 seen above and to the right of center in the above photograph. The bright star on the left is located in the belt of the familiar constellation of Orion.