Astronomy Picture Of the Day (APOD)Sunset Moonlight
November's lunar eclipse was one of the shortest in recent years and also one of the brightest -- demonstrating that the Earth's shadow is not completely dark. The eclipsed Moon remained easily visible...
Voyager at 90 AU
Launched in 1977, Voyager 1 is now about 12 light-hours or 90 astronomical units (AU) from the Sun, making this spacecraft humanity's most distant ambassador to the cosmos. Well beyond the orbits...
Light Can Twist as Well as Spin
Light is more complicated than we thought. When astronomers measure light, they are usually concerned with its direction, energy, and spin polarization (sometimes). Recently, however, it has been more broadly realized that photons...
Leonids Over Indian Cove
One year ago today an impressive meteor shower graced the skies of Earth. Pictured above from last year, at least six bright meteors are visible in only part of the sky above Indian Cove campground in California, USA, during a four-minute exposure.
Canis Major Dwarf: A New Closest Galaxy
What is the closest galaxy to the Milky Way? The new answer to this old question is the Canis Major dwarf galaxy. For many years astronomers thought the Large Magellan Cloud (LMC) was closest, but its title was supplanted in 1994 by the Sagittarius dwarf galaxy.
Leonids from Leo
Is Leo leaking? Leo, the famous sky constellation visible on the left of the above all-sky photograph, appears to be the source of all the meteors seen in 1998's Leonids Meteor Shower. That...
LL Orionis: When Cosmic Winds Collide
This arcing, graceful structure is actually a bow shock about half a light-year across, created as the wind from young star LL Orionis collides with the Orion Nebula flow. Adrift in Orion's stellar...
Every day is a cloudy day on Jupiter, the Solar System's reigning gas giant. And swirling cloud tops are all you see in this stunningly detailed true color image, a portion of a large digital mosaic portrait of Jupiter recorded from the Cassini spacecraft during its Jovian flyby in December 2000.
Nestled in the central US, the state of Oklahoma is noted for its gorgeous prairie skies and wide-open spaces, but not for frequent visitations of the northern lights. Still, following the intense solar activity...
Mars Then and Now
Does Mars have canals? A hot debate topic of the late 1800s, several prominent astronomers including Percival Lowell not only claimed to see an extensive system of long straight canals on Mars, but used them to indicate that intelligent life exists there.