Black Holes and Galactic Centers
13.01.1997

Do all galaxies have black holes at their centers? Although not even a single galaxy has yet been proven to have a central black hole, the list of candidates has increased yet again. Recent...

Goa Silhouettes
21.03.2007

On Moonday, March 19, shortly before the equinox, locations in Asia and the Arctic were favoured by the New Moon's shadow during a partial solar eclipse. Although the view from Goa, India found...

A Fire Rainbow Over New Jersey
10.06.2008

What is that inverted rainbow in the sky? Sometimes known as a fire rainbow for its flame-like appearance, a circumhorizon arc is created by ice, not fire. For a circumhorizon arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds are present.

A Partial Lunar Eclipse
28.06.2010

What's happened to the Moon? This past weekend, once again, part of the Moon moved through the Earth's shadow. This happens about once or twice a year, on the average, but not each month since the Moon's orbit around the Earth is slightly tilted.

Hunter s Moon over the Alps
3.11.2012

A Full Moonset can be a dramatic celestial sight, and Full Moons can have many names. Late October's Full Moon, the second Full Moon after the northern hemisphere autumnal equinox, has been traditionally called the Hunter's Moon.

A Halo Around the Moon
21.04.2003

Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.

Hale-Bopp: Climbing Into Southern Skies
15.05.1997

Fighting the glow of the setting sun and the city lights of Cape Town, South Africa, comet Hale-Bopp is just visible near the center of this panoramic view - photographed on May 3rd.

Comet Halley and the Milky Way
3.10.1997

Comet Halley was photographed superposed in front of the disk of our Milky Way Galaxy in 1986 by the Kuiper Airborne Observatory. Comet Halley is the bright white streak near this photograph's center. Comet Halley is the most famous comet in history, and returns to the inner Solar System every 76 years.

Aurora Over Clouds
10.09.2003

Aurorae usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact air molecules high in the Earth's atmosphere. An oxygen molecule, for example, will glow in a green light when reacquiring an electron lost during a collision with a solar particle.

Saturns Rings in Natural Color
23.07.2004

What colors are Saturn's rings? Recent images from the Cassini spacecraft now orbiting Saturn confirm that different rings have slightly different colors. The above image shows their sometimes-subtle differences in brightness and color. The rings reflect sunlight and so, even if they were perfectly reflecting, would appear the color of the Sun.