Astronomy Picture Of the Day (APOD)Arecibo: The Largest Telescope
The Arecibo radio telescope is currently the largest single-dish telescope in the world. First opening in 1963, this 305 meter (1000 foot) radio telescope resides in a natural valley of Puerto Rico. The Arecibo...
The 76 Meter Lovell Radio Telescope
Jodrell Bank in England is the home of the Lovell Telescope one of the largest radio telescopes in the world. Completed in 1957 under the direction of Bernard Lovell, the 250 ft. diameter dish was the largest steerable radio telescope.
Rampaging Fronts of the Veil Nebula
A supernova explosion of a high-mass star results in fast moving blast waves. At the front of the waves shown above, ionized gas in the Veil Supernova Remnant rushes out from the explosion, sweeps up material, and breaks up many atoms into constituent ions and electrons.
Jets From SS433
SS433 is one of the most exotic star systems known to astronomers. Its unremarkable name stems from its inclusion in a catalog of stars which emit radiation characteristic of atomic hydrogen. Its very remarkable behavior stems from a compact object, a black hole or neutron star, which has produced an accretion disk with jets.
A Black Hole in M87's Center?
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 lower left of the above photograph.
Uranus' Largest Moon: Titania
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.
Uranus' Moon Ariel: Valley World
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 moon's surface.
Von Braun's Wheel
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 rocket pioneer Wernher von Braun.
A Mysterious Cone Nebula
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 light from the emission nebula and open cluster NGC 2264 behind it.
Julius Caesar and Leap Days
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 leap day every four years.