The center of nearby giant galaxy M87 is a dense and violent place. In this 1994 photograph by the Hubble Space Telescope, a disk of hot gas was found to be orbiting at the center of this massive elliptical galaxy. The disk is evident on the ...
Titania's tortured terrain is a mix of valleys and craters. NASA's interplanetary robot spacecraft Voyager 2 passed this moon of Uranus in 1986 and took the above photograph. The photograph was then transmitted back to earth by radio. The valleys ...
What formed Ariel's valleys? This question presented itself when Voyager 2 passed this satellite of Uranus in January 1986. Speculation includes that heating caused by the ancient tides of Uranus caused moonquakes and massive shifting of the ...
Orbiting 1,075 miles above the Earth, a 250 foot wide, inflated, reinforced nylon "wheel" was conceived in the early 1950s to function as a navigational aid, meteorological station, military platform, and way station for space exploration by ...
Sometimes the simplest shapes are the hardest to explain. For example, the origin of the mysterious cone-shaped region located just below the center of the above picture remains a mystery. The dark region clearly contains much dust which blocks ...
Today, February 29th, is a leap day - a relatively rare occurrence. Advised by Alexandrian astronomer Sosigenes, Roman dictator Julius Caesar, pictured above in a self-decreed minted coin, created a calender system in 46 BC that contained one ...
Tremendous explosions near the center of our Galaxy were discovered just this past December and are being announced today by a paper in Nature and a press conference at NASA. Bursts like these have never been seen before, and so the exact cause ...
An X-ray star winks out behind the Moon in these before and after views of a lunar occultation of the galactic X-ray source designated GX5-1. The false color images were made using data from the ROSAT orbiting observatory and show high energy ...
On rare but spectacular occasions, fireballs, meteors brighter than the brightest stars, flash through the heavens - sometimes making audible sounds and occasionally surviving to strike the Earth's surface. The path of one such fireball, recorded ...
Looking like a fleet of futuristic starcruisers poised over planet Earth, NASA's highly successful series of High Energy Astrophysical Observatory (HEAO) spacecraft appear above in a vintage illustration. Labeled A, B, and C in this conceptual ...