Night Sky Reflections from the Worlds Largest Mirror
21.10.2019

What's being reflected in the world's largest mirror? Stars, galaxies, and a planet. Many of these stars are confined to the grand arch that runs across the image, an arch that is the central plane of our home Milky Way Galaxy. Inside the arch is another galaxy -- the neighboring Large Magellanic Cloud (LMC).

Moon and Planets Sky
25.03.2004

Look up into the sky tonight and without a telescope or binoculars you might have a view like this one of Moon, planets and stars. The lovely photo was taken on March 23rd, and captures the crescent Moon on the horizon with Venus above it. Both brilliant celestial bodies are over-exposed.

Highlights of the Summer Sky
4.06.2017

What's up in the sky this summer? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early summer sky events fan out toward the left, while late summer events are projected toward the right.

A Sky Filled with Leonids
4.12.2001

In the early morning hours of November 19, amateur Chen Huang-Ming caught a sky filled with astronomical wonders. With his fisheye camera set up on Ho-Huan Mountain in Taiwan for a half-hour exposure, he started the above image a local time of 2:33 am.

APOD: 2024 June 9 Б How to Identify that Light in the Sky
8.06.2024

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

Trails in the Morning Sky
28.07.2012

Brilliant Venus and bright Jupiter still rise together before dawn. The peaceful waters by a small lakeside house near Stuttgart, Germany reflect their graceful arcing trails in this composited series of exposures, recorded on the morning of July 26.

The Radio Sky: Tuned to 408MHz
3.04.1999

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.

A Dark and Dusty Sky
21.05.2015

In the dusty sky toward the constellation Taurus and the Orion Arm of our Milky Way Galaxy, this broad mosaic follows dark and faint reflection nebulae along the region's fertile molecular cloud.

A Sky Full Of Hydrogen
17.12.1996

Interstellar space is filled with extremely tenuous clouds of gas which are mostly Hydrogen. The neutral hydrogen atom (HI in astronomer's shorthand) consists of 1 proton and 1 electron. The proton and electron spin like tops but can have only two orientations; spin axes parallel or anti-parallel.

APOD: 2024 May 20 Б Aurora Dome Sky
19.05.2024

It seemed like night, but part of the sky glowed purple. It was the now famous night of May 10, 2024, when people over much of the world reported beautiful aurora-filled skies. The featured image was captured this night during early morning hours from Arlington, Wisconsin, USA.