Sunset from the International Space Station
23.06.2010

What are these strange color bands being seen from the International Space Station? The Sun setting through Earth's atmosphere. Pictured above, a sunset captured last month by the ISS's Expedition 23 crew shows in vivid detail many layers of the Earth's thin atmosphere.

A Year of Dark Cosmology
30.12.2001

We live in the exciting time when humanity discovers the nature of our entire universe. During this year, in particular, however, the quest for cosmological understanding appears to have astronomers groping in the dark.

A Fading Moonset Over Hong Kong
14.12.2009

Do stars appear dimmer when nearer the horizon? Yes -- atmospheric air absorbs and reradiates light, so that the greater the airmass through which one peers, the fainter an object will appear. Pictured above in a multi-frame image, stars, the planet Jupiter, and even the Moon show the horizon-dimming effects of Earth's nearly-transparent atmosphere.

Launch of the IXPE Observatory
21.12.2021

Birds don't fly this high. Airplanes don't go this fast. The Statue of Liberty weighs less. No species other than human can even comprehend what is going on, nor could any human just a millennium ago. The launch of a rocket bound for space is an event that inspires awe and challenges description.

100 Hours of Astronomy Begins
2.04.2009

Today, 100 Hours of Astronomy begins, a cornerstone project of the International Year of Astronomy 2009 celebrating the 400th anniversary of Gallileo's original telescopic exploration of the sky. Running from April 2 through...

APOD: 2025 August 25 Б The Meteor and the Star Cluster
24.08.2025

Sometimes even the sky surprises you. To see more stars and faint nebulosity in the Pleiades star cluster (M45), long exposures are made. Many times, less interesting items appear on the exposures that were not intended -- but later edited out.

Meteors, Planes, and a Galaxy over Bryce Canyon
19.05.2014

Sometimes land and sky are both busy and beautiful. The landscape pictured in the foreground encompasses Bryce Canyon in Utah, USA, famous for its many interesting rock structures eroded over millions of years.

Frosted Leaf Orion
16.11.2010

Sometimes, you can put some night sky in your art. Captured above Japan earlier this month, a picturesque night sky was photographed behind a picturesque frosted leaf. The reflecting ice crystals on the leaf coolly mimic the shining stars far in the background.

The Gegenschein Over Chile
2.12.2012

Is the night sky darkest in the direction opposite the Sun? No. In fact, a rarely discernable faint glow known as the gegenschein (German for "counter glow") can be seen 180 degrees around from the Sun in an extremely dark sky. The gegenschein is sunlight back-scattered off small interplanetary dust particles.

A Meteor and the Gegenschein
11.05.2021

Is the night sky darkest in the direction opposite the Sun? No. In fact, a rarely discernable faint glow known as the gegenschein (German for "counter glow") can be seen 180 degrees around from the Sun in an extremely dark sky. The gegenschein is sunlight back-scattered off small interplanetary dust particles.