Astronomy Picture Of the Day (APOD)Orion over El Castillo
Welcome to the December solstice, a day the world does not end ... even according to the Mayan Calendar. To celebrate, consider this dramatic picture of Orion rising over El Castillo, the central pyramid at Chichén Itzá, one of the great Mayan centers on the Yucatán peninsula.
M33: Triangulum Galaxy
The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way.
NGC 5189: An Unusually Complex Planetary Nebula
Why is this nebula so complex? When a star like our Sun is dying, it will cast off its outer layers, usually into a simple overall shape. Sometimes this shape is a sphere, sometimes a double lobe, and sometimes a ring or a helix.
A Sun Pillar Over Sweden
Have you ever seen a sun pillar? When the air is cold and the Sun is rising or setting, falling ice crystals can reflect sunlight and create an unusual column of light. Ice sometimes forms flat, six-sided shaped crystals as it falls from high-level clouds.
NGC 922: Collisional Ring Galaxy
Why does this galaxy have so many big black holes? No one is sure. What is sure is that NGC 922 is a ring galaxy created by the collision of a large and small galaxy about 300 million years ago.
MWC 922: The Red Square Nebula
What could cause a nebula to appear square? No one is quite sure. The hot star system known as MWC 922, however, appears to be embedded in a nebula with just such a shape. The above image combines infrared exposures from the Hale Telescope on Mt.
When Gemini Sends Stars to Paranal
From a radiant point in the constellation of the Twins, the annual Geminid meteor shower rained down on planet Earth this week. Recorded near the shower's peak in the early hours of December...
On the morning of November 14, sky gazers from around the world gathered on this little planet to stand in the dark umbral shadow of the Moon. Of course, the Moon cast the shadow...
Apollo 17: A Stereo View from Lunar Orbit
Get out your red/blue glasses and check out this awesome stereo view of another world. The scene was recorded by Apollo 17 mission commander Eugene Cernan on December 11, 1972, one orbit before descending to land on the Moon.
Milky Way Over Quiver Tree Forest
In front of a famous background of stars and galaxies lies some of Earth's more unusual trees. Known as quiver trees, they are actually succulent aloe plants that can grow to tree-like proportions. The quiver tree name is derived from the historical usefulness of their hollowed branches as dart holders.