A Comet Tail Horizon
23.01.2007

What's happening over the horizon? Many a sky enthusiast who thought they had seen it all had never seen anything like this. To the surprise of many Northern Hemisphere observers, the tail of Comet McNaught remained visible even after the comet's head set ahead of the Sun.

Solstice Conjunction over Budapest
22.06.2017

Before a solstice Sun rose on June 21, brilliant Venus and an old crescent Moon posed together over Budapest, Hungary for this predawn skyscape. In the foreground the view looks across the Danube river from Buda to Pest toward the dome and peaks of the Hungarian Parliament building.

Saturn and Jupiter in Summer 2020
11.12.2020

During this northern summer Saturn and Jupiter were both near opposition, opposite the Sun in planet Earth's sky. Their paired retrograde motion, seen about every 20 years, is followed from 19 June through 28 August in this panoramic composite as they wander together between the stars in western Capricornus and eastern Sagittarius.

Full Moon over Brno
15.09.2016

After sunset this gorgeous full moon rose over Brno city in the Czech Republic on July 20, 2016. The panoramic image was made during a celebration of the 47th anniversary of the Apollo 11 lunar landing.

APOD: 2024 July 9 Б Noctilucent Clouds over Florida
8.07.2024

These clouds are doubly unusual. First, they are rare noctilucent clouds, meaning that they are visible at night -- but only just before sunrise or just after sunset. Second, the source of these noctilucent clouds is actually known.

A Rainbow Pileus Cloud over Zimbabwe
19.02.2014

Yes, but how many dark clouds have a multicolored lining? Pictured, behind this darker cloud, is a pileus iridescent cloud, a group of water droplets that have a uniformly similar size and so together diffract different colors of sunlight by different amounts.

Aurora at Midnight
5.05.1998

What's happening behind those trees? Aurora. This picture was taken at midnight near Fairbanks, Alaska, and captures familiar trees, common clouds, and a glowing sky markedly different than a sunset. Particularly strange is the green auroral ring caused by ionized oxygen high in the Earth's atmosphere.

Aurora Persei
9.08.2008

Dark skies are favored for viewing meteor showers -- so the best viewing of this year's Perseids will occur in the early morning. While the Perseid meteor shower is scheduled to peak over...

Saturn in the Milky Way
9.06.2017

Saturn is near opposition in planet Earth's sky. Rising at sunset and shining brightly throughout the night, it also lies near a line-of-sight to crowded starfields, nebulae, and obscuring dust clouds along the Milky Way.

A Flock of Stars
6.09.2008

Only a few stars can be found within ten light-years of our lonely Sun, situated near an outer spiral arm of the Milky Way galaxy. But if the Sun were found within one of our galaxy's star clusters, thousands of stars might occupy a similar space.