Astronomy Picture Of the Day (APOD)Pelican Nebula Ionization Front
The Pelican Nebula is slowly being transformed. IC 5070, the official designation, is divided from the larger North America Nebula by a molecular cloud filled with dark dust. The Pelican, however, receives much study because it is a particularly active mix of star formation and evolving gas clouds.
Gamma Ray Burst: A Milestone Explosion
Gamma-Ray Bursts (GRBs) were discovered by accident. Thirty three years ago today, satellites first recorded a GRB. The data plotted here show that the count rate of the satellite gamma-ray instrument abruptly jumped indicating a sudden flash of gamma-rays.
Ultraviolet Earth from the Moon
Here's a switch: the above picture is of the Earth taken from a lunar observatory! This false color picture shows how the Earth glows in ultraviolet (UV) light. UV light is so blue humans can't see it.
Galactic Centre Starscape
Thirty thousand light-years distant, beyond the majestic dust clouds of the constellation Sagittarius, lies the centre of our Milky Way Galaxy. Hidden from optical view by the dust, the Galactic Centre region is a relatively unexplored starscape.
BATSE GRB Final Sky Map
What causes the most powerful explosions in the universe? The BATSE modules that flew on the Compton Gamma Ray Observatory allowed more insight into enigmatic gamma-ray burst (GRB) explosions than ever before. From 1991-2000, BATSE detected 2704 GRBs, much more than ever previously recorded.
M63: The Sunflower Galaxy
One of the bright spiral galaxies visible in the north sky is M63, the Sunflower Galaxy. M63, also catalogued as NGC 5055, can be found with a small telescope in the constellation of Canes Venaciti.
Newton Crater: Evidence for Recent Water on Mars
What could have formed these unusual channels? Inside a small crater that lies inside large Newton Crater on Mars, numerous narrow channels run from the top down to the crater floor. The above picture covers a region spanning about 3000 meters across.
Shapley 1: An Annular Planetary Nebula
What happens when a star runs out of nuclear fuel? The center condenses into a white dwarf while the outer atmospheric layers are expelled into space and appear as a planetary nebula. This particular planetary nebula, designated Shapley 1 after the famous astronomer Harlow Shapley, has a very apparent annular ring like structure.
Sunlight Through Saturns Rings
Normally, earth-bound astronomers view Saturn's spectacular ring system fully illuminated by reflected sunlight. However, this intriguing picture was made to take advantage of an unusual orientation, with the Sun actually illuminating the rings from below. The three bright ring features are visible because the rings themselves are not solid.
The Gullies Of Mars
The recently revealed gullies on Mars are rare. But they may prove to be sites of present day, near surface, liquid water, holding out the tantalizing possibility of martian life. Too small to have...