M27: Not A Comet
While searching the skies above 18th century France for comets, astronomer Charles Messier diligently recorded this object as number 27 on his list of things which are definitely not comets. So what is it? Well, 20th century astronomers would ...
Far Side of the Moon
Locked in synchronous rotation, the Moon always presents its well-known near side to Earth. But from lunar orbit, Apollo astronauts also grew to know the Moon's far side. This sharp picture from Apollo 16's mapping camera shows the eastern edge ...
Ocean Planet Pole To Pole
The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) instrument onboard the orbiting SeaStar spacecraft can map subtle differences in Earth's ocean color. These North (left) and South Pole projections are based on SeaWiFS measurements made between ...
Comet Williams in 1998
The brightest comet in the sky right now is Comet Williams. Moving slowly though the constellation of Centaurus, Comet Williams, at magnitude 8, is visible to Southern Hemisphere observers with binoculars. In ten days, Comet Williams will reach ...
A Sunspot Up Close
Sometimes, small regions of the Sun appear unusually dark. Visible above is a close-up picture of a sunspot, a depression on the Sun's face that is slightly cooler and less luminous than the rest of the Sun. The Sun's complex magnetic field ...
One Small Step
On July 20th, 1969, a human first set foot on the Moon. Pictured above is the first lunar footprint. The footprint and distinction of the first person to walk on the Moon belong to Neil Armstrong. It has been estimated that one billion people ...
Sputnik: Traveling Companion
Sputnik means "traveling companion". Despite the innocuous sounding name, the launch of the Earth's first "artificial moon", Sputnik 1, by the Soviets on October 4, 1957 shocked the free world, setting in motion events which resulted in the ...
Magnetar In The Sky
Indicated on this infrared image of the galactic center region is the position of SGR 1900+14 - the strongest known magnet in the galaxy. SGR 1900+14 is believed to be a city-sized, spinning, super-magnetic neutron star, or Magnetar. How strong ...
Happy 40th Birthday, NASA!
Happy Birthday, NASA! The National Aeronautics and Space Administration officially began operations on October 1, 1958, absorbing its forerunner organization the National Advisory Committee for Aeronautics, NACA. Its landmark achievements in ...
Spiral Galaxy NGC 1232
Galaxies are fascinating not only for what is visible, but for what is invisible. Grand spiral galaxy NGC 1232, recently captured in detail by the new Very Large Telescope, is a good example. The visible is dominated by millions of bright stars ...
