Astronomy Picture Of the Day (APOD)Lulin and Saturn near Opposition
Tracking through the constellation Leo on February 23rd, bright planet Saturn and Comet Lulin were both near opposition -- opposite the Sun in planet Earth's sky. They also passed within only 2 degrees of each other creating a dramatic celestial photo-op.
Moon, Mercury, Jupiter, Mars
When the Moon rose in predawn skies on February 23rd, it sported a sunlit crescent. It also offered early morning risers a tantalizing view of earthshine, the dark portion of the lunar disk illuminated by sunlight reflected from the Earth.
Two Tails of Comet Lulin
Go outside tonight and see Comet Lulin. From a dark location, you should need only a good star map and admirable perseverance -- although wide-field binoculars might help. Yesterday, Comet Lulin passed its closest to Earth, so that the comet will remain near its brightest over the next few days.
Barnards Loop around the Horsehead Nebula
Why is the Horsehead Nebula surrounded by a bubble? Although hard to make out above, the famous Horsehead Nebula is the slight dark indentation in the bright streak just to the left of the image center. Glowing like an emission nebula, the origin of the bubble, known as Barnard's Loop, is currently unknown.
An Etruscan Vase Moon Rising
What's happened to the Moon? Nothing, although from some locations, February's full moon, which occurred about two weeks ago, appeared strangely distorted as it rose. Visible in particular was a curiously inverted...
Orion Nebula: The Hubble View
Few cosmic vistas excite the imagination like the Orion Nebula. Also known as M42, the nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1,500 light-years away.
The Swift View of Comet Lulin
Now growing brighter, Comet Lulin is headed for its closest approach to planet Earth early next week. But the comet's greenish glow, familiar to earthbound skygazers, is replaced by false colors in this premier view from the orbiting Swift satellite.
Snake in the Dark
Dark nebulae snake across a gorgeous expanse of stars in this telescopic view toward the pronounceable constellation Ophiuchus and the center of our Milky Way Galaxy. In fact, the twisting central shape seen here is well known as the Snake Nebula.
Mauna Kea Milky Way Panorama
Aloha and welcome to a breathtaking skyscape. The dreamlike panoramic view looks out from the 4,200 meter volcanic summit of Mauna Kea, Hawai'i, across a layer of clouds toward a starry night sky and the rising Milky Way.
Satellites Collide in Low Earth Orbit
How often do satellites collide? Although minuscule space debris may strike any satellite on occasion, the first known collision between time two full satellites occurred only last week. Even though thousands of satellites have been launched, the low collision rate is caused by the great vastness of space.