NGC 1818: A Young Globular Cluster
14.02.1997

Globular clusters once ruled the Milky Way. Back in the old days, back when our Galaxy first formed, perhaps thousands of globular clusters roamed our Galaxy. Today, there are perhaps 200 left. Many globular clusters were destroyed over the eons by repeated fateful encounters with each other or the Galactic center.

X-Ray Pleiades
18.03.1997

The Pleiades star cluster is one of the jewels of the northern sky. To the unaided eye it appears as a lovely and tantalizing grouping of stars in the constellation of Taurus, while telescopic views reveal cluster stars surrounded by delicate blue wisps of dust-reflected starlight.

Stars Without Galaxies
15.02.1998

Galaxies are made up of stars, but are all stars found within galaxies? Using the Hubble Space Telescope, researchers exploring the Virgo Cluster of galaxies have now found about 600 red giant stars adrift in intergalactic space. Above is an artist's vision of the sky from a hypothetical planet of such a lonely sun.

Anticrepuscular Rays Over Florida
17.09.2006

What's happening over the horizon? Although the scene may appear somehow supernatural, nothing more unusual is occurring than a setting Sun and some well placed clouds. Strangely, the actual sunset was occurring in the opposite direction from where the camera was pointing. Pictured above are anticrepuscular rays.

1999 JM8: A Rock Too Close
1.09.1999

Nearly four kilometers across, the huge rock known as 1999 JM8 silently passed only 8.5 million kilometers from the Earth in early August. The small asteroid was completely unknown before May. Every few centuries, a rock like this impacts the Earth, with the potential to disrupt modern civilization.

Saturns Rings from the Other Side
9.06.2008

What do Saturn's rings look like from the other side? From Earth, we usually see Saturn's rings from the same side of the ring plane that the Sun illuminates them. Geometrically...

Labtayt Sulci on Saturns Enceladus
22.12.2008

Do some surface features on Enceladus roll like a conveyor belt? A leading interpretation of recent images taken of Saturn's most explosive moon indicate that they do. This form of asymmetric tectonic activity...

Hole in the Sun
28.08.2010

This ominous, dark shape sprawling across the face of the Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space. Studied...

Saturn: Light, Dark, and Strange
12.10.2010

What's creating those dark bands on Saturn? Sometimes it takes a little sleuthing to figure out the how and why of a picture taken by the Saturn-orbiting Cassini spacecraft. Let's see. That large orb on the left must be Saturn itself. Those arcs on the right are surely the rings.

MyCn18: An Hourglass Planetary Nebula
7.08.2011

The sands of time are running out for the central star of this hourglass-shaped planetary nebula. With its nuclear fuel exhausted, this brief, spectacular, closing phase of a Sun-like star's life occurs as its outer layers are ejected - its core becoming a cooling, fading white dwarf.