Astronomy Picture Of the Day (APOD)X-rays From The Cat's Eye
Haunting patterns within planetary nebula NGC 6543 readily suggest its popular moniker -- the Cat's Eye nebula. In 1995, a stunning false-color optical image from the Hubble Space Telescope detailed the swirls of this glowing nebula, known to be the gaseous shroud expelled from a dying sun-like star about 3,000 light-years from Earth.
Watch the Sky Rotate
If you could watch the sky for an entire night, what would you see? The above time-lapse sequence from the CONtinuous CAMera (CONCAM) project shows the answer for the skies above Kitt Peak National Observatory on 2000 December 23.
A Cosmic Call to Nearby Stars
If you could send a message to an alien civilization, what would you say? The people from the Cosmic Call project sent the above image as the first page of a longer message. The message was broadcast toward local stars by a radio telescope in
Help NASA Classify Martian Craters
The large Martian crater above just left of center: is this a fresh crater, a degraded crater, or a ghost crater? Complex image recognition tasks like these are currently done more reliably by a human than a computer.
Tycho Brahe Measures the Sky
Tycho Brahe was the most meticulous astronomical observer of his time. Brahe, who lived between 1546 and 1601, set out to solve the day's most pressing astronomical problem: to determine whether the Earth or the Sun was at the center of the Solar System.
Apollo 17's Moonship
Awkward and angular looking, Apollo 17's lunar module Challenger was designed for flight in the vacuum of space. This sharp picture from the command module America, shows Challenger's ascent stage in lunar orbit.
Second Millennium, Last Eclipse
Christmas Day 2000 featured the final eclipse of the Second Millennium -- a partial solar eclipse visible from much of North America. Astrophotographer Phil Rau recorded the entire event on a single image as the Sun and Moon arced through winter skies above Cary, North Carolina, USA.
Third Millennium, First Eclipse
The first eclipse of the third millennium is coming up! A total lunar eclipse mainly visible from Europe, Asia, and Africa, will occur on January 9th as the full Moon glides through the long, but not so dark shadow of planet Earth. Why not so dark?
M8: In the Center of the Lagoon Nebula
In the center of the Lagoon Nebula one finds glowing gas, star clusters, and dense knots of gas and dust just now forming stars. The young open cluster of stars, designated NGC 6523, can be seen in the center of the above image. These stars emit energetic light that ionizes the surrounding hydrogen gas.
Jupiter, Europa, and Callisto
As the robot Cassini spacecraft rounds Jupiter on its way toward Saturn, it has taken a sequence of images of the gas giant with its four largest moons. Previously released images have highlighted Ganymede and Io. Pictured above are the two remaining Galilean satellites: Europa and Callisto.