Astronomy Picture Of the Day (APOD)Io Aurora
Alluring aurora surrounding Io (eye-oh) appear as a ghostly glow while the volcanic moon orbits within Jupiter's dark shadow. Gas giant Jupiter is off to the right of this image, recorded in May by the robot Galileo spacecraft's solid state imaging camera from a distance of about 1.3 million kilometers.
A Great Day For SOHO
The last 10 days have been great days for SOHO, the space-based SOlar and Heliospheric Observatory. Contact was completely lost with this international research spacecraft over 3 months ago but recovery teams have reacquired control of SOHO and, beginning October 5th, have been successfully switching on its scientific instruments.
The Worlds Largest Ozone Hole
It's back, and it's bigger than ever. The ozone hole that has been a cause of concern in recent years has again reformed over Earth's South Pole. The seasonal recurrence of the ozone hole was expected, although the size of the hole has never been so large this early in the season.
In the Center of the Dumbbell Nebula
Here's part of the Dumbbell Nebula that you can't see through binoculars. To see this, we suggest a sophisticated spectrograph attached to a telescope with an 8-meter aperture. Pictured above is the central part of the Dumbbell Nebula, also known as M27 and NGC 6853.
The Hubble Deep Field in Infrared
Galaxies this faint have never been seen before. In 1996 the Hubble Space Telescope (HST) created one of the most famous pictures of modern astronomy, the Hubble Deep Field (HDF). Now HST has returned to a piece of the HDF for a long exposure by its new NICMOS camera, sensitive to infrared light.
Most stars appear only as points of light. Early last year, Betelgeuse became the second star, after our Sun, to have it surface resolved. Later last year, Mira was added to the list. Mira...
Maria Mitchell Inspires a Generation
"Do not look at stars as bright spots only - try to take in the vastness of the universe." October 1st was the 151st anniversary of the day Maria Mitchell swept the sky with her telescope and discovered the comet of 1847 (comet Mitchell 1847VI).
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?
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...
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 September 1997 and July 1998.