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.

Auroras over Northern Canada
9.10.2022

Gusting solar winds and blasts of charged particles from the Sun resulted in several rewarding nights of auroras back in 2014 December, near the peak of the last 11-year solar cycle. The featured image captured dramatic auroras stretching across a sky near the town of Yellowknife in northern Canada.

A Gegenschein Lunar Eclipse
14.10.2015

Is there anything interesting to see in the direction opposite the Sun? One night last month, there were quite a few things. First, the red-glowing orb on the lower right of the featured image is the full moon, darkened and reddened because it has entered Earth's shadow.

The View from Everest
23.07.2002

What would it be like to stand atop the tallest mountain on Earth? To see a full panoramic vista from there, scroll right. Visible are snow peaked mountains near and far, tremendous cliffs, distant plateaus, the tops of clouds, and a dark blue sky. Mt.

Comet Hale-Bopp Develops a Tail
12.02.1997

Comet Hale-Bopp has quite a tail to tell already. This remarkable comet was first discovered in 1995, even before Comet Hyakutake. Since then, this erupting snowball continues to fall into our inner Solar System and is starting to put on quite a show.

The View from Everest
31.08.2003

What would it be like to stand atop the tallest mountain on Earth? To see a full panoramic vista from there, scroll right. Visible are snow peaked mountains near and far, tremendous cliffs, distant plateaus, the tops of clouds, and a dark blue sky. Mt.

Where is Upsilon Andromedae
22.04.1999

Astronomers recently announced the detection of three large planets orbiting the star Upsilon Andromedae - the first planetary system known to orbit a normal star other than our Sun. These planets were not directly photographed but found through a Doppler technique developed to use large telescopes to search nearby stars for wobbling planetary signatures.

Noctilucent Cloud Storm Panorama
11.07.2009

Noctilucent or night-shining clouds lie near the edge of space. From about 80 kilometers above Earth's surface, the icy clouds can still reflect sunlight even though the Sun itself is below the horizon as seen from the ground.

APOD: 2025 January 21 Б Comet ATLAS over Brasilia
21.01.2025

What's that in the sky? Above the city, above most clouds, far in the distance: it's a comet. Pictured, the impressive tail of Comet C/2024 G3 (ATLAS) was imaged from Brasцlia, Brazil four days ago.

Fireball!
26.02.1996

On rare but spectacular occasions, fireballs, meteors brighter than the brightest stars, flash through the heavens - sometimes making audible sounds and occasionally surviving to strike the Earth's surface. The path of one such...