Watch the Sky Rotate
10.01.2001

If you could watch the sky for an entire night, what would you see? The above time-lapse sequence from the CONtinuous CAMera (CONCAM) project shows the answer for the skies above Kitt Peak National Observatory on 2000 December 23.

Equinox in the Sky
22.09.2020

Does the Sun set in the same direction every day? No, the direction of sunset depends on the time of the year. Although the Sun always sets approximately toward the west, on an equinox like today the Sun sets directly toward the west.

The Radio Sky: Tuned to 408MHz
26.11.1996

Tune your radio telescope to 408MHz (408 million cycles per second) and check out the Radio Sky! You should find that frequency on your dial somewhere between US broadcast television channels 13 and 14.

Circles in the Sky
16.05.2008

Gazing skyward on a sunny day in May, photographer Jean-Marc Lecleire captured this engaging display of ice halos forming complete circles in the sky. Recorded with a fish-eye lens from a spot near the grand Château de Chambord in France, the picture looks straight up, spanning almost 180 degrees from horizon to horizon.

How to Identify that Light in the Sky
9.06.2014

What is that light in the sky? Perhaps one of humanity's more common questions, an answer may result from a few quick observations. For example -- is it moving or blinking?

A Northern Winter Sky Panorama
24.12.2019

What stars shine in Earth's northern hemisphere during winter? The featured image highlights a number of bright stars visible earlier this month. The image is a 360-degree horizontal-composite panorama of 66 vertical frames taken consecutively with the same camera and from the same location at about 2:30 am.

APOD: 2023 March 8 Б Artificial Night Sky Brightness
8.03.2023

Where have all the dim stars gone? From many places on the Earth including major cities, the night sky has been reduced from a fascinating display of thousands of stars to a diffuse glow through which only a few stars are visible.

A Dark Sky over Death Valley
8.05.2007

This eerie glow over Death Valley is in danger. Scrolling right will show a spectacular view from one of the darkest places left in the continental USA: Death Valley, California. The above 360-degree full-sky panorama is a composite of 30 images taken two years ago in Racetrack Playa.

A Furious Sky over Mount Shasta
28.09.2022

Is the sky angry with Mount Shasta? According to some ancient legends, the spirits of above and below worlds fight there, sometimes quite actively during eruptions of this enormous volcano in California, USA. Such drama can well be imagined in this deep sky image taken in late June.

The Radio Sky: Tuned to 408MHz
14.12.1997

Tune your radio telescope to 408MHz (408 million cycles per second) and check out the Radio Sky! You should find that frequency on your dial somewhere between US broadcast television channels 13 and 14.