Astronomy Picture Of the Day (APOD)The Cartwheel Galaxy
The Cartwheel Galaxy shows a ring that is the result of a collision between a small and a large galaxy. After a small galaxy has moved through a big galaxy - in this case...
The Hooker Telescope on Mt. Wilson
In the 1920s, pictures from the Hooker Telescope on Mt. Wilson fundamentally changed our understanding of the cosmos. Astronomer Edwin Hubble, using photographs he took with this telescope, demonstrated that the objects his contemporaries called "spiral nebulae" were actually huge systems of stars - spiral galaxies, similar to our own Milky Way galaxy but incredibly distant.
Ida and Dactyl: Asteroid and Moon
An asteroid with a moon! The robot spacecraft Galileo whose primary mission is to explore the Jupiter system, has encountered and photographed two asteroids during its long journey to Jupiter. The second asteroid...
The Earth-Moon System
A double planet? From 4 million miles away on December 16, 1992, NASA's robot spacecraft Galileo took this picture of the Earth-moon system. The bright, sunlit half of the Earth contrasts strongly with the darker subdued colors of the moon. Our moon is one of the largest moons in the solar system.
The Cat's Eye Nebula
Three thousand light years away, a dying star throws off shells of glowing gas. This Hubble Space Telescope image reveals "The Cat's Eye Nebula" to be one of the most complex "planetary nebulae" known.
An Ultraviolet Image of M101
This giant spiral galaxy, Messier 101 (M101), was photographed by the Ultraviolet Imaging Telescope onboard the Space Shuttle Endeavour during the Astro-2 mission (March 2 - 18, 1995). The image has been computer processed so that the colors represent the intensity of ultraviolet light.
Spiral Galaxy M100
The M100 galaxy is a large spiral galaxy similar to our own Milky Way, containing over 100 billion stars. It is over 150 million light years away, so the light we see left when dinosaurs roamed the Earth.
Jupiter from Voyager
Imagine a hurricane that lasted for 300 years! This picture of the planet Jupiter was taken by the Voyager 1 spacecraft as it passed the planet in 1979. Jupiter, a gas giant planet with no solid surface, is the largest planet in the solar system and is made mostly of the hydrogen and helium.
Gamma Ray Crab, Geminga
What if you could "see" in gamma-rays? If you could, these two spinning neutron stars or pulsars would be among the brightest objects in the sky. This computer processed image shows the Crab Nebula pulsar (below and right of center) and the Geminga pulsar (above and left of center) in the "light" of gamma-rays.
Gamma Ray Sky Map
What if you could "see" gamma rays? This computer processed image represents a map of the entire sky at photon energies above 100 million electron Volts. These gamma-ray photons are more than 40 million times more energetic than visible light photons and are blocked from the Earth's surface by the atmosphere.