Astronomy Picture Of the Day (APOD)Pauli Exclusion Principle: Why You Don't Implode
Why doesn't matter just bunch up? The same principle that keeps neutron stars and white dwarf stars from imploding also keeps people from imploding and makes normal matter mostly empty space. The observed reason is known as the Pauli Exclusion Principle.
Dawn s Endeavour
On February 21st, the Space Shuttle Endeavour and the International Space Station (ISS) flew through the sky near dawn over Whitby, Ontario, Canada. Along with star trails, both were captured in this single time exposure. Glinting in sunlight 350 kilometers above the Earth, Endeavour slightly preceeded the ISS arcing over the horizon.
A jewel of the southern sky, the Great Carina Nebula, aka NGC 3372, spans over 300 light-years. Near the upper right of this expansive skycape, it is much larger than the more northerly Orion Nebula.
Edge on Spiral Galaxy NGC 891
This beautiful cosmic portrait features NGC 891. The spiral galaxy spans about 100 thousand light-years and is seen almost exactly edge-on from our perspective. In fact, about 30 million light-years distant in the constellation Andromeda, NGC 891 looks a lot like our Milky Way.
Astronaut Installs Panoramic Space Window
This space job was almost complete. Floating just below the International Space Station, astronaut Nicholas Patrick put some finishing touches on the newly installed cupola space windows last week. Patrick was a mission specialist onboard the recently completed space shuttle Endeavor's STS-130 mission to the ISS.
Exceptional Rocket Waves Destroy Sun Dog
What created those rocket waves, and why did they destroy that sun dog? Close inspection of the above image shows not only a rocket rising near the center, but unusual air ripples around it and a colorful sundog to the far right.
Galaxy Group Hickson 31
Will the result of these galactic collisions be one big elliptical galaxy? Quite possibly, but not for another billion years. Pictured above, several of the dwarf galaxies of in the Hickson Compact Group 31 are seen slowly merging.
NGC 2440: Cocoon of a New White Dwarf
Like a butterfly, a white dwarf star begins its life by casting off a cocoon that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the ejected shell of gas would become the prettiest of all!
Put a satellite in a circular orbit about 42,000 kilometers from the center of the Earth (36,000 kilometers or so above the surface) and it will orbit once in 24 hours. Because that matches Earth's rotation period, it is known as a geosynchronous orbit.
WISE Infrared Andromeda
This sharp, wide-field view features infrared light from the spiral Andromeda Galaxy (M31). Dust heated by Andromeda's young stars is shown in yellow and red, while its older population of stars appears as a bluish haze. The false-color skyscape is a mosaic of images from NASA's new Wide-field Infrared Survey Explorer (WISE) satellite.