A Double Star Cluster in Perseus
17.11.2020

Most star clusters are singularly impressive. Open clusters NGC 869 and NGC 884, however, could be considered doubly impressive. Also known as "h and chi Persei", this unusual double cluster, shown above, is bright enough to be seen from a dark location without even binoculars.

Ice Fishing for Cosmic Neutrinos
29.04.2001

Scientists are melting holes in the bottom of the world. In fact, several holes have been melted near the South Pole, and they are now being used as astronomical observatories. Astronomers with the Antarctic Muon and Neutrino Detector Array (AMANDA) lower into each vertical lake a string knotted with basketball-sized light detectors.

Simulating the Universe
7.11.1995

The above cube represents a chunk of our universe as simulated by the Grand Challenge Cosmology Consortium (GC3). The cube is huge - it would take light 500 million years to cross it. Low density gas is shown as blue, and high density gas as red.

M1: Polarization of the Crab
22.11.1995

The Crab Nebula resulted from a star that exploded - a supernova. Although the stellar explosion that caused the Crab Nebula was seen over 900 years ago, the nebula itself still expands and shines. Much of the emitted light has been found to be polarized. Light waves with the same polarization vibrate in the same plane.

Night Lightning on Jupiter
15.12.1997

Why is there lightning on Jupiter? Lightning is a sudden rush of electrically charged particles from one location to another. To create lightning, charges must first separate inside a cloud. On Earth, drafts of colliding ice and water droplets usually create this charge separation, but what happens on Jupiter?

Jupiters Moons Thebe, Amalthea, and Metis
8.05.2000

The robot spacecraft Galileo in orbit around Jupiter has recently photographed the inner moons of Jupiter in greater detail than ever before. These pictures of Thebe, Amalthea, and Metis are shown to scale, and reveal details as small as three kilometers across. Amalthea, by contrast, has a total length of about 200 kilometers.

Ceci n est pas un Meteore
19.08.2006

To paraphrase Magritte, "This is not a meteor". It's not a picture of a meteor either, but it was taken during last weekend's peak of the Perseid Meteor shower. Skywatching with friends...

Nova Over Iran
18.02.2007

A bright new nova is being studied by astronomers. The officially dubbed Nova Scorpii 2007 has become so bright in recent days that it is now visible to the unaided eye. Adventurous early morning sky enthusiasts should look in dark skies toward the constellation of the Scorpion, just below Jupiter and Antares.

A Spherule from Outer Space
11.01.2003

When a meteorite strikes the Moon, the energy of the impact melts some of the splattering rock, a fraction of which might cool into tiny glass beads. Many of these glass beads were present in lunar soil samples returned to Earth by the Apollo missions.

GRB970228: What's There?
7.04.1997

Could this fuzzy blob be the key to the whole gamma-ray burst (GRB) mystery? Astronomers the world over are now scrambling to determine the true nature of the extended emission seen to the lower right of the bright source in the above image.