A High Energy Fleet
24.05.1998

Looking like a fleet of futuristic starcruisers, NASA's highly successful series of High Energy Astrophysical Observatory (HEAO) spacecraft appear poised over planet Earth. Labeled A, B, and C in this vintage illustration, the spacebased telescopes were known as HEAO-1, HEAO-2, and HEAO-3 respectively.

Zooming in to the Pelican Nebula
2.07.2007

Where on the sky is the Pelican Nebula? APOD features many objects on the night sky, but usually does not have the resources to show exactly where on the night sky each objects lies.

Hot Stars in the Southern Milky Way
7.05.1999

Hot blue stars, red glowing hydrogen gas, and dark, obscuring dust clouds are strewn through this dramatic region of the Milky Way in the southern constellation of Ara (the Altar). About 4,000 light-years from Earth, the stars at the left are young, massive, and energetic.

Hot Stars in the Southern Milky Way
22.12.2001

Hot blue stars, red glowing hydrogen gas, and dark, obscuring dust clouds are strewn through this dramatic region of the Milky Way in the southern constellation of Ara (the Altar). About 4,000 light-years from Earth, the stars at the left are young, massive, and energetic.

Lunar Shadow Transit
11.03.2016

This snapshot from deep space captures planet Earth on March 9. The shadow of its large moon is falling on the planet's sunlit hemisphere. Tracking toward the east (left to right) across the ocean-covered world the moon shadow moved quickly in the direction of the planet's rotation.

Inside The Elephant's Trunk
9.04.2005

In December of 2003, the world saw spectacular first images from the Spitzer Space Telescope, including this penetrating interior view of an otherwise opaque dark globule known as the Elephant's Trunk Nebula. Seen...

Aurora in the Backyard
18.03.2015

On the night of March 17/18 this umbrella of northern lights unfolded over backyards in Vallentuna, Sweden about 30 kilometers north of Stockholm. A result of the strongest geomagnetic storm of this solar cycle...

ELT and the Milky Way
16.03.2024

The southern winter Milky Way sprawls across this night skyscape. Looking due south, the webcam view was recorded near local midnight on March 11 in dry, dark skies over the central Chilean Atacama desert.

The Sudbury Neutrino Detector
23.06.1999

Two thousand meters below the ground, a giant sphere has begun to detect nearly invisible particles. These particles, neutrinos, are extremely abundant in the universe but usually go right through just about everything.

Layer Cake Sunset
20.01.2017

On January 18 a tantalizing sunset was captured in this snapshot. Seemingly sliced into many horizontal layers the Sun shimmered moments before it touched the horizon, setting over the Pacific Ocean as seen from the mountaintop Las Campanas Observatory in Chile.