Crescent Saturn
8.08.2020

From Earth, Saturn never shows a crescent phase. But when viewed from a spacecraft the majestic giant planet can show just a sunlit slice. This image of crescent Saturn in natural color was taken by the robotic Cassini spacecraft in 2007.

NGC4039: Starbirth and Galaxy Death
6.05.1997

Do star clusters form when galaxies collide? Quite possibly, according to Hubble Space Telescope observations of the "Antennae", two galaxies thought to be in the early stages of a collision.

IC 405: The Flaming Star Nebula
24.11.2003

Rippling dust and gas lanes give the Flaming Star Nebula its name. The red and purple colors of the nebula are present in different regions and are created by different processes. The bright star...

Star Factory Messier 17
18.04.2013

Sculpted by stellar winds and radiation, the star factory known as Messier 17 lies some 5,500 light-years away in the nebula-rich constellation Sagittarius. At that distance, this degree wide field of view spans almost 100 light-years.

Into the Shadow
24.01.2020

On January 21, 2019 moonwatchers on planet Earth saw a total lunar eclipse. In 35 frames this composite image follows the Moon that night as it crossed into Earth's dark umbral shadow. Taken...

APOD: 2024 December 3 Б Ice Clouds over a Red Planet
3.12.2024

If you could stand on Mars -- what might you see? You might look out over a vast orange landscape covered with rocks under a dusty orange sky, with a blue-tinted Sun setting over the horizon, and odd-shaped water clouds hovering high overhead.

Frosty Mountains on Mars
30.07.2003

What causes the unusual white color on some Martian mountains? The answer can be guessed by noticing that the bright areas disappear as springtime takes hold in the south of Mars: dry ice. Unlike water ice, dry carbon dioxide ice sublimates directly to gas from its frozen state.

A Perseid Meteor
11.08.1997

Tonight the Perseid Meteor Shower reaches its maximum. Grains of rocky ice will streak across the sky as they evaporate during entry into Earth's atmosphere. These ice chips were shed from Comet Swift-Tuttle. The Perseids result from the annual crossing of the Earth through Comet Swift-Tuttle's orbit.

La Nina Watch
20.07.1998

Goodbye El Niño. Hello La Niña? Scientists are watching to see if an evolving pool of relatively cool water in the mid-Pacific Ocean will develop into a full "La Niña". Over the past several months, the water temperature in the Equatorial Pacific Ocean has been doing a flip-flop.

Northern and Southern Owls
6.05.2010

Captured in colorful telescopic portraits, two cosmic owls glare back toward planet Earth in this intriguing comparison of planetary nebulae. On the left is M97 in the constellation Ursa Major, also known in the northern hemisphere as the Owl Nebula.