Astronomy Picture Of the Day (APOD)Follow The Spots
The Sun rotates on its axis about once every 27 days. How can you tell? Just follow the sunspots. This composite picture was constructed from solar images recorded daily by the MDI instrument on board the space-based SOlar and Heliospheric Observatory (SOHO).
NGC 2261: Hubbles Variable Nebula
What causes Hubble's Variable Nebula to vary? The unusual nebula pictured above changes its appearance noticeably in just a few weeks. Discovered over 200 years ago and subsequently cataloged as NGC 2661, the remarkable nebula is named for Edwin Hubble, who studied it earlier this century.
Earth's North Magnetic Pole
A magnetic compass does not point toward the true North Pole of the Earth. Rather, it more closely points toward the North Magnetic Pole of the Earth. The North Magnetic Pole is currently located in northern Canada.
NGC 3603: An Active Star Cluster
NGC 3603 is home to a massive star cluster, thick dust pillars, and a star about to explode. The central open cluster contains about 2000 bright stars, each of which is much brighter and more massive than our Sun.
Black Holes in Galactic Centers
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 continues to increase. Results...
Maria Mitchell Inspires a Generation
"Do not look at stars as bright spots only - try to take in the vastness of the universe." On October 1, 1847 Maria Mitchell swept the sky with her telescope and discovered a comet (comet Mitchell 1847VI).
On July 31, 1964, Ranger 7 crashed into the Moon. Seventeen minutes before impact it snapped this picture - the first image of the Moon ever taken by a U.S. spacecraft. Of course Ranger 7 was intended to crash, transmitting close-up pictures of the lunar surface during its final moments.
Moon Over Eugenia
Eugenia is an asteroid with a moon! This animation was constructed from infrared discovery images of the Eugenia-moon system taken in November 1998 using the Canada-France-Hawaii Telescope (CFHT). Main belt asteroid Eugenia, represented here as a central white patch, is a mere 215 kilometers in diameter.
Ozone Hole Reduced
Although a new ozone hole has formed again this year over the South Pole, this time it is a little bit smaller than the year before. Ozone is important because it shields us from damaging ultraviolet sunlight. Ozone is vulnerable, though, to CFCs and halons being released into the atmosphere.
NGC 2346: A Butterfly Shaped Planetary Nebula
It may look like a butterfly, but it's bigger than our Solar System. NGC 2346 is a planetary nebula made of gas and dust that has evolved into a familiar shape. At the heart of the bipolar planetary nebula is a pair of close stars orbiting each other once every sixteen days.