Astronomy Picture Of the Day (APOD)Halo of the Cat's Eye
The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this stunning false-color picture, processed...
A Dark and Stormy Night
It was a dark and stormy night. But on August 29th the red planet Mars, near it's closest approach to Earth in almost 60,000 years, shone brightly in the sky against a background of stars in the constellation Aquarius.
Aurora in Colorado Skies
Vivid auroral displays were triggered by a cloud of high energy particles from the Sun that collided with planet Earth's magnetosphere yesterday, October 29, at about 06:30 Universal Time. The collision...
A Powerful Solar Flare
Yesterday, our Sun produced one of the most powerful solar flares in recorded history. Seen across the electromagnetic spectrum, the Sun briefly became over 100 times brighter in X-rays than normal. Over the next few days, as energetic particles emitted from these regions strike the Earth, satellite communications might be affected and auroras might develop.
The SDSS 3D Universe Map
The latest map of the cosmos again indicates that dark matter and dark energy dominate our universe. The Sloan Digital Sky Survey (SDSS) is on its way to measuring the distances to over one million galaxies.
Large Sunspot Groups 10484 and 10486
Two unusually large sunspot groups are now crossing the face of the Sun. Each group, roughly the size of Jupiter, is unusual not only for its size but because it is appearing over three years after solar maximum, the peak of solar surface activity.
M16: Stars from Eagles EGGs
Newborn stars are forming in the Eagle Nebula. This image, taken with the Hubble Space Telescope in 1995, shows evaporating gaseous globules (EGGs) emerging from pillars of molecular hydrogen gas and dust. The giant pillars are light years in length and are so dense that interior gas contracts gravitationally to form stars.
Islands in the Photosphere
Awash in a sea of plasma and anchored in magnetic fields, sunspots are planet-sized, dark islands in the solar photosphere, the bright surface of the Sun. Before the enlightened(!) age of cameras, solar observers created detailed drawings of sunspots as they changed and progressed across the visible solar disk.
This year's record close approach of Mars inspired many to enjoy telescopic views of the red planet. But while Mars was so bright it was hard to miss, spotting Mars' two diminutive moons was still a good test for observers with modest sized instruments.
Looking toward the constellation Cygnus, a stunning and complex region of nebulae strewn along the plane of our Milky Way galaxy is revealed in this unique wide-angle sky view. Recorded with a filter designed...