The Hill, The Moon, and Saturn
15.11.2018

Last Sunday when the Moon was young its sunlit crescent hung low near the western horizon at sunset. With strong earthshine it was joined by Saturn shining in the early evening sky for a beautiful conjunction visible to skygazers around our fair planet.

Messier 2
3.04.2019

After the Crab Nebula, M1, this giant star cluster is the second entry in 18th century astronomer Charles Messier's famous list of things with are not comets. M2 is one of the largest globular star clusters now known to roam the halo of our Milky Way galaxy.

The 100 Meter Green Bank Radio Telescope
10.03.2002

The largest single-dish fully steerable radio telescope began operation in 2000 August in Green Bank, West Virginia, USA. Dedicated as the Robert C. Byrd Green Bank Telescope, the device weighs over 30 times more than the Statue of Liberty, and yet can point anywhere in the sky more precisely than one thousandth of a degree.

APOD: 2026 July 6 Б Dueling Bands over the Atacama Desert
5.07.2026

What are these two bands in the sky? The more commonly seen band is on the left and is the central band of our Milky Way galaxy. Our Sun orbits in the disk of this spiral galaxy so that from inside, it appears as a band of comparable brightness all the way around the sky.

Leonids Over Monument Valley
19.11.2012

What's happening in the sky over Monument Valley? A meteor shower. Over the past weekend the Leonid meteor shower has been peaking. The image -- actually a composite of six exposures of about 30 seconds each -- was taken in 2001, a year when there was a much more active Leonids shower.

Roque de los Muchachos Observatory
19.08.2002

Above the clouds, atop an island off the coast of Africa, a group of cutting-edge telescopes inspects the universe. Pictured above are telescopes at Roque de los Muchachos Observatory on La Palma, one of the Canary Islands, Spain. The site is one of the premier observing locations on Earth.

Perseid over Albrechtsberg Castle
9.08.2013

Medieval Albrechtsberg castle is nestled in trees near the northern bank of the river Pielach and the town of Melk, Austria. In clearing night skies on August 12, 2012 it stood under constellations of the northern summer, including Aquarius, Aquila, and faint, compact Delphinus (above and right of center) in this west-looking skyview.

The Largest Impact Crater
6.09.1996

What is the largest known impact crater in the Solar System? Over 1300 miles across, the South Pole-Aitken Basin on the farside of Earth's Moon holds that distinction. Circled above in a false color mosaic of Clementine images it was caused when an asteroid or comet sized object crashed

A Perseid Aurora
9.08.2003

Just after the Moon set but before the Sun rose in the early morning hours of 2000 August 12, meteors pelted the Earth from the direction of the constellation Perseus, while ions pelted the Earth from the Sun.

Meteor by Moonlight
15.08.2009

Dark skies are favored for viewing meteor showers. But the annual Perseid Meteor Shower still entertained skygazers around the world this week even though the Moon brightened the night. At its last quarter phase...