Astronomy Picture Of the Day (APOD)Infrared Ring Nebula
The classic appearance of the popular Ring Nebula (aka M57) is understood to be due to perspective - our view from planet Earth looks down the center of a roughly barrel-shaped cloud of gas.
NGC 1499: California Nebula
Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States. Our own Sun also lies within the Milky Way's Orion Arm, only about 1,500 light-years from the California Nebula.
A Sun Halo Over Tennessee
Sometimes it looks like the Sun is being viewed through a large lens. In the above case, however, there are actually millions of lenses: ice crystals. As water freezes in the upper atmosphere, small, flat, six-sided, ice crystals might be formed.
Crater on Mimas
Whatever hit Mimas nearly destroyed it. What remains is one of the largest impact craters on one of Saturn's smallest moons. The crater, named Herschel after the 1789 discoverer of Mimas, Sir William Herschel, spans about 130 kilometers and is pictured above in the dramatic light of its terminator.
Mercury Over Leeds
Have you ever seen the planet Mercury? This week might be a good time. Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth's sky. If trailing the Sun, Mercury will be visible low on the horizon for only a short while after sunset.
The View from Everest
What would it be like to stand atop the tallest mountain on Earth? To see a full panoramic vista from there, scroll right. Visible are snow peaked mountains near and far, tremendous cliffs, distant plateaus, the tops of clouds, and a dark blue sky. Mt.
Tycho and Copernicus: Lunar Ray Craters
Dazzling in binoculars or a small telescope, the Moon is pocked with impact craters. During partial lunar phases, the craters along the terminator are cast in dramatic relief by strong shadows. But when the Moon is full some craters seem to sprout systems of bright radial lines or rays.
NGC 1427A: Galaxy in Motion
In this tantalizing image, young blue star clusters and pink star-forming regions abound in NGC 1427A, a galaxy in motion. The small irregular galaxy's swept back outline points toward the top of this...
Still Life with NGC 2170
In this beautiful celestial still life composed with a cosmic brush, dusty nebula NGC 2170 shines at the upper left. Reflecting the light of nearby hot stars, NGC 2170 is joined by other bluish reflection nebulae and a compact red emission region against a backdrop of stars.
The Powerful Sumatra Andaman Islands Earthquake
December's 9.0 earthquake has likely shortened Earth's day by about three microseconds and may also have tweaked Earth's rotational wobble. The megathrust earthquake occurred as the Indian tectonic plate slid further beneath the Burma tectonic plate.