Millions of Stars in Omega Centauri
16.04.2002

Pictured above is the largest ball of stars in our Galaxy. About 10 million stars orbit the center of this globular cluster - named Omega Centauri - as this giant globular cluster orbits our Galactic center.

A Supernova in the Whirlpool
21.04.1996

In 1994, a new star in a distant galaxy was seen by amateur astronomers, who alerted the world to their discovery of a supernova. Near the nucleus of spiral galaxy M51, popularly known...

Comet Hyakutake's Orbit
13.03.1996

Where did Comet Hyakutake come from? The orbits of the Earth and this brightening comet are shown in the above diagram. The blue disk is bounded by the circular orbit of the Earth about the central Sun. The comet's path outlines the green shape.

APOD: 2025 May 5 Б Planet Lines Across Water
4.05.2025

WhatБs causing those lines? Objects in the sky sometimes appear reflected as lines across water Б but why? If the waterБs surface is smooth, then reflected objects would appear similarly -- as spots.

VLT: A New Largest Optical Telescope
1.09.1996

What is the largest telescope in the world? In the optical, this title was long held by the Hale 200-inch, and is presently held by the Keck telescopes in Hawaii. But an even larger optical telescope is being built.

Cold Wind From The Boomerang Nebula
15.10.1997

A cold wind blows from the central star of the Boomerang Nebula. Seen here in a false color image of dust reflected starlight, the nebula lies about 5,000 light-years away. The boomerang shaped...

Space Walz
10.02.1997

Astronaut Carl Walz waves at his colleagues from the aft end of the Space Shuttle Discovery's payload bay - during a 1993 spacewalk to evaluate tools, tethers, and a foot restraint slated for use in the first Hubble Space Telescope servicing mission.

The Milky Way Over Paranal
22.01.2007

It's not the sky that's falling. More accurately, the Earth is rising. The Earth's rotation gives a continually changing view to all Earth observers, including those measuring the universe at the Paranal Observatory.

The Large Cloud Of Magellan (LMC)
23.01.1998

Ferdinand Magellan and his crew had plenty of time to study the southern sky during their famous voyage around the world. As a result, two fuzzy cloud-like objects, not visible to northern hemisphere dwellers, are now known as the Clouds of Magellan.

The Perseus Cluster of Galaxies
25.10.2004

Here is one of the largest objects that anyone will ever see on the sky. Each of the fuzzy blobs in the above picture is a galaxy, together making up the Perseus Cluster, one of the closest clusters of galaxies.