Kitt Peak National Observatory
18.01.1999

At the top of Kitt Peak Mountain near Tucson, Arizona lies one of the world's great collections of telescopes. As pictured, in the dome at the far left lies the 3.5-meter WIYN Telescope, famous recently for tracking distant supernovae.

The Color of the Moon
16.02.2006

Earth's Moon is normally seen in subtle shades of grey or yellow. But small color differences have been greatly exaggerated to make this dramatic mosaic image of the Moon's gibbous phase. The familiar Sea of Tranquility (Mare Tranquillitatis) is the blue area right of center.

Abell 3627 in the Great Attractor
18.02.1996

Are these galaxies near the center of the largest gravitationally bound concentration of mass yet known? Previously, the cluster of galaxies known as Abell 3627 was largely unstudied because dust in the disk of our own Galaxy obscured much of its light.

Cloud, Clusters and Comet Siding Spring
4.09.2014

On October 19th, a good place to watch Comet Siding Spring will be from Mars. Then, this inbound visitor (C/2013 A1) to the inner solar system, discovered in January 2013 by Robert McNaught at Australia's Siding Spring Observatory, will pass within 132,000 kilometers of the Red Planet.

Here Comes Comet Hyakutake
13.03.1996

The reaction of ancient peoples to the appearance of bright comets has toppled empires, de-throned kings, and been taken as a sign of great things to come. Probably some of these comets did not get as bright as Comet Hyakutake ("hyah-koo-tah-kay") will in the next two weeks.

Radio Jupiter
9.10.2003

This view of gas giant Jupiter, made from data recorded at the Very Large Array radio observatory near Socorro, New Mexico, may not look too familiar. In fact, there is no sign of a bright, round planet striped with cloud bands, sporting a Great Red Spot.

Geminid Meteors over Xinglong Observatory
13.12.2020

Where do Geminid meteors come from? In terms of location on the sky, as the featured image composite beautifully demonstrates, the sand-sized bits of rock that create the streaks of the Geminids meteor shower appear to flow out from the constellation of Gemini.

Local Group Galaxy NGC 205
8.01.1996

The Milky Way Galaxy is not alone. It is part of a gathering of about 25 galaxies known as the Local Group. Members include the Great Andromeda Galaxy (M31), M32, M33, the Large Magellanic Clouds, the Small Magellanic Clouds, Dwingeloo 1, several small irregular galaxies, and many dwarf elliptical galaxies.

Supernova Remnant N132D in Optical and X Rays
25.10.2005

Thousands of years after a star exploded, its expanding remnant still glows brightly across the spectrum. Such is the case with N132D, a supernova remnant located in the neighboring Large Magellanic Cloud (LMC) galaxy. The expanding shell from this explosion now spans 80 light-years and has swept up about 600 Suns worth of mass.

M13: The Great Globular Cluster in Hercules
15.11.2007

M13 is modestly recognized as the Great Globular Cluster in Hercules. A system of stars numbering in the hundreds of thousands, it is one of the brightest globular star clusters in the northern sky.