Star Colors in Orion
11.02.2011

What determines a star's color? Its temperature. Red stars are cool, with surface temperatures of around 3,000 kelvins (K), while blue stars are hotter and can have temperatures over 30,000 K. Our own lovely "yellow" Sun's temperature is a comforting 6,000 K.

The Perseid Meteor Shower
9.08.1996

From a radiant point in the constellation of Perseus, Comet Swift-Tuttle presents -- The Perseid Meteor Shower -- coming to your night sky this weekend! A bookish E. C. Herrick of New Haven, Connecticut correctly suspected in 1837 that this meteor shower was an annual event.

The Snake Nebula in Ophiuchus
24.08.1997

What slithers there? The dark winding lanes visible in part of the constellation Ophiuchus belong to the Snake Nebula. The Snake Nebula is a series of dark absorption clouds made up of Interstellar dust. Interstellar dust grains - composed predominantly of carbon - absorb visible starlight and reradiate much of it in the infrared.

The Snake Nebula in Ophiuchus
11.08.1996

What slithers there? The dark curly lanes visible in part of the constellation Ophiuchus belong to the Snake Nebula. The Snake Nebula is a series of dark absorption clouds. Interstellar dust grains - composed predominantly of carbon - absorb visible starlight and reradiate much of it in the infrared.

Aurora Over Cape Cod
2.07.2003

Active pillars of colorful aurora were captured dancing over a serenely smooth and nearly colorless Cape Cod Bay last month. North is straight ahead so that the town lights near the center originate from Provincetown, Massachusetts, USA. The unusual red colors in the aurora slightly reflect off the ocean inlet.

The Winter Hexagon
6.11.2002

Some of the brightest stars form a large and easily found pattern in the winter sky of Earth's northern hemisphere. Dubbed the Winter Hexagon, the stars involved can usually be identified even in the bright night skies of a big city.

Neutron Star Earth
16.06.1995

If the Earth could somehow be transformed to the ultra-high density of a neutron star , it might appear as it does in the above computer generated figure. Due to the very strong gravitational field, the neutron star distorts light from the background sky greatly. If you look closely, two

An Annotated Leonid
30.11.1998

The 1998 Leonids Meteor Shower was perhaps the most photographed meteor event in history. Patient observers saw bright meteors streak across dark skies every few minutes, frequently leaving fading trails stretching across the sky. High above the Anza-Borrego Desert, a meteor was photographed streaking up from the radiant constellation of the Leonids: Leo.

Antares
24.06.1997

Antares is a huge star. In a class called red supergiant, Antares is about 700 times the size of our own Sun, 15 times more massive, and 10,000 times brighter. Antares is the brightest star in the constellation of Scorpius and one of the brighter stars in all the night sky.

The Sky Towards Sagittarius
7.09.1998

A variety of stars and nebulae can be found towards the constellation of Sagittarius. Dense fields of stars laced with dark lanes of dust crowd this region only a few degrees from the center of our Galaxy.