

For billions of years, massive stars in our Milky Way Galaxy have lived spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star formation begins anew. The expanding debris cloud known as Cassiopeia A is an example of this final phase of the stellar life cycle. Light from the explosion which created this supernova remnant was probably first seen in planet Earth's sky just over 300 years ago, although it took that light more than 10,000 years to reach us.
Surely one of the most gorgeous sights the solar system has to offer, Saturn sits enveloped by the full splendor of its stately rings. Taking in the rings in their entirety was the focus of this particular imaging sequence. Therefore, the camera exposure times were just right to capture the dark-side of its rings, but longer than that required to properly expose the globe of sunlit Saturn. Consequently, the sunlit half of the planet is overexposed.
Soft hues, partially lit orbs, a thin trace of the ring, and slight shadows highlight this understated view of the majestic surroundings of the giant planet Saturn. Looking nearly back toward the Sun, the robot Cassini spacecraft now orbiting Saturn captured crescent phases of Saturn and its moon Rhea in color a few months ago.
The helmet visor of astronaut John "Danny" Olivas, STS-117 mission specialist, serves as an easel of sorts as it reflects a pictorial account of a portion of a very busy session of extravehicular activity in 2007. Olivas, who took the photo, spent two hours of an overall 7 hour, 58 minute spacewalk stapling and pinning down a piece of thermal blanket on one of Atlantis' orbital maneuvering system pods (reflected in his visor).
While drifting through the cosmos, a magnificent interstellar dust cloud became sculpted by stellar winds and radiation to assume a recognizable shape. Fittingly named the Horsehead Nebula, it is embedded in the vast and complex Orion Nebula. The dark molecular cloud, roughly 1,500 light years distant, is cataloged as Barnard 33 and is visible only because its obscuring dust is silhouetted against the bright emission nebula IC 434.
A new diffuse ring, coincident with the orbits of Saturn's moon's Janus and Epimetheus, has been revealed in ultra-high phase angle views from Cassini. Ultra-high phase angle indicates the sun is behind the target. The new ring is visible in this image outside the overexposed main rings and interior to the G and E rings. The G ring has a sharp inner boundary; the E ring is extremely broad and arcs across the upper and lower portions of the scene.
The Apollo 11 mission, the United States first lunar landing mission, is seen at liftoff in 1969.
This symmetric cloud dubbed the Boomerang Nebula was created by a high-speed wind of gas and dust blowing from an aging central star at speeds of nearly 400,000 miles per hour. The rapid expansion has cooled molecules in the nebular gas to about one degree above absolute zero - colder than even the cosmic background radiation - making it the coldest known region in the distant Universe.
These two galaxies are interacting in a surprising way, connected by a "pipeline" of obscuring material that runs between them over 20,000 light-years of intergalactic space. Silhouetted by starlight, the dark, dusty ribbon appears to stretch from NGC 1410 (the galaxy at the left) and wrap itself around NGC 1409 (at right). A mere 300 million light-years distant in the constellation of Taurus, the pair's recent collision has likely drawn out this relatively thin lane of material which is only about 500 light-years wide.
Nestled in the central US, the state of Oklahoma is noted for its gorgeous prairie skies and wide-open spaces, but not for frequent visitations of the northern lights. Still, following the intense solar activity, aurora did come sweeping down the Oklahoma plains and skywatcher Dave Ewoldt managed to catch up with this photogenic apparition 40 miles northwest of Oklahoma City at about 3am CST on October 29.