It may look like a grazing seahorse, but the dark object toward the image right is actually a pillar of smoky dust about 20 light years long. The curiously-shaped dust structure occurs in our neighboring Large Magellanic Cloud, in a star forming region very near the expansive Tarantula Nebula. The energetic nebula is creating a star cluster, NGC 2074, whose center is visible just off the top of the image in the direction of the neck of the seahorse. The representative color image was taken in 2008 by the Hubble Space Telescope's Wide Field Planetary Camera 2 in honor of Hubble's 100,000th trip around the Earth. As young stars in the cluster form, their light and winds will slowly erode the dust pillars away over the next million years. Now Available: APOD 2015 Wall Calendars

It may look like a grazing seahorse, but the dark object toward the image right is actually a pillar of smoky dust about 20 light years long. The curiously-shaped dust structure occurs in our neighboring Large Magellanic Cloud, in a star forming region very near the expansive Tarantula Nebula. The energetic nebula is creating a star cluster, NGC 2074, whose center is visible just off the top of the image in the direction of the neck of the seahorse. The representative color image was taken in 2008 by the Hubble Space Telescope's Wide Field Planetary Camera 2 in honor of Hubble's 100,000th trip around the Earth. As young stars in the cluster form, their light and winds will slowly erode the dust pillars away over the next million years. Now Available: APOD 2015 Wall Calendars

Get out your red/blue glasses and float next to a comet! The Rosetta mission lander Philae's ROLIS camera snapped the two frames used to create this stereo anaglyph for 3D viewing during its November 12 descent to the nucleus of Comet 67P/Churyumov-Gerasimenko. The comet's curious double lobed nucleus is seen nearly end on from a distance of about 3 kilometers, about 1 hour before Philae arrived at the surface. Philae's initial landing site is near the center of the front facing lobe. Part of a landing gear foot cuts across the upper right corner, in the close foreground of the 3D-view. Philae bounced twice in the comet's weak gravity after its first contact with the surface. Using high resolution camera images from the Rosetta orbiter along with data from the lander's instruments, controllers have followed Philae's impromptu journey over the comet's surface and have identified a likely area for its final resting place.

Get out your red/blue glasses and float next to a comet! The Rosetta mission lander Philae's ROLIS camera snapped the two frames used to create this stereo anaglyph for 3D viewing during its November 12 descent to the nucleus of Comet 67P/Churyumov-Gerasimenko. The comet's curious double lobed nucleus is seen nearly end on from a distance of about 3 kilometers, about 1 hour before Philae arrived at the surface. Philae's initial landing site is near the center of the front facing lobe. Part of a landing gear foot cuts across the upper right corner, in the close foreground of the 3D-view. Philae bounced twice in the comet's weak gravity after its first contact with the surface. Using high resolution camera images from the Rosetta orbiter along with data from the lander's instruments, controllers have followed Philae's impromptu journey over the comet's surface and have identified a likely area for its final resting place.

Look through the cosmic cloud cataloged as NGC 281 and you might miss the stars of open cluster IC 1590. But, formed within the nebula, that cluster's young, massive stars ultimately power the pervasive nebular glow. The eye-catching shapes looming in this portrait of NGC 281 are sculpted columns and dense dust globules seen in silhouette, eroded by intense, energetic winds and radiation from the hot cluster stars. If they survive long enough, the dusty structures could also be sites of future star formation. Playfully called the Pacman Nebula because of its overall shape, NGC 281 is about 10,000 light-years away in the constellation Cassiopeia. This sharp composite image was made through narrow-band filters, combining emission from the nebula's hydrogen, sulfur, and oxygen atoms in green, red, and blue hues. It spans over 80 light-years at the estimated distance of NGC 281.

Looping through the Jovian system in the late 1990s, the Galileo spacecraft recorded stunning views of Europa and uncovered evidence that the moon's icy surface likely hides a deep, global ocean. Galileo's Europa image data has been newly remastered here, using improved new calibrations to produce a color image approximating what the human eye might see. Europa's long curving fractures hint at the subsurface liquid water. The tidal flexing the large moon experiences in its elliptical orbit around Jupiter supplies the energy to keep the ocean liquid. But more tantalizing is the possibility that even in the absence of sunlight that process could also supply the energy to support life, making Europa one of the best places to look for life beyond Earth. What kind of life could thrive in a deep, dark, subsurface ocean? Consider planet Earth's own extreme shrimp.

A 24 minute sequence from top to bottom, this intriguing series of telescopic frames tracks the occultation of Io by Callisto, two of Jupiter's Galilean moons, from San Pietro Polesine, Italy, planet Earth. A challenging observational project using a small telescope, the two contrasting Jovian worlds are both slightly larger than Earth's Moon. In fact, bright, volcanic Io and dark, cratered Callisto are about 3,640 and 4,820 kilometers in diameter respectively. With Earth itself now crossing near the orbital plane of Jupiter's moons, astronomers are enjoying a season of Galilean moon mutual events ranging from eclipses to occultations. The series of orbital plane crossings produce a mutual event season every 5 to 6 years.

A 24 minute sequence from top to bottom, this intriguing series of telescopic frames tracks the occultation of Io by Callisto, two of Jupiter's Galilean moons, from San Pietro Polesine, Italy, planet Earth. A challenging observational project using a small telescope, the two contrasting Jovian worlds are both slightly larger than Earth's Moon. In fact, bright, volcanic Io and dark, cratered Callisto are about 3,640 and 4,820 kilometers in diameter respectively. With Earth itself now crossing near the orbital plane of Jupiter's moons, astronomers are enjoying a season of Galilean moon mutual events ranging from eclipses to occultations. The series of orbital plane crossings produce a mutual event season every 5 to 6 years.

What creature lurks near the red Lagoon nebula? Mars. This gorgeous color deep-sky photograph has captured the red planet passing below two notable nebulae -- cataloged by the 18th century cosmic registrar Charles Messier as M8 and M20. M20 (upper right of center), the Trifid Nebula, presents a striking contrast in red/blue colors and dark dust lanes. Just below and to the left is the expansive, alluring red glow of M8, the Lagoon Nebula. Both nebulae are a few thousand light-years distant. By comparison, temporarily situated below them both, is the dominant "local" celestial beacon Mars. Taken late last month posing near its southernmost point in Earth's sky, the red planet was 14 light-minutes away. Now Available: APOD 2015 Wall Calendars

The scene might have been considered serene if it weren't for the tornado. During 2004 in Kansas, storm chaser Eric Nguyen photographed this budding twister in a different light -- the light of a rainbow. Featured here, a white tornado cloud descends from a dark storm cloud. The Sun, peeking through a clear patch of sky to the left, illuminates some buildings in the foreground. Sunlight reflects off raindrops to form a rainbow. By coincidence, the tornado appears to end right over the rainbow. Streaks in the image are hail being swept about by the high swirling winds. Over 1,000 tornadoes, the most violent type of storm known, occur on Earth every year, many in tornado alley. If you see a tornado while driving, do not try to outrun it -- park your car safely, go to a storm cellar, or crouch under steps in a basement. Follow APOD on: Facebook, Google Plus, or Twitter

The scene might have been considered serene if it weren't for the tornado. During 2004 in Kansas, storm chaser Eric Nguyen photographed this budding twister in a different light -- the light of a rainbow. Featured here, a white tornado cloud descends from a dark storm cloud. The Sun, peeking through a clear patch of sky to the left, illuminates some buildings in the foreground. Sunlight reflects off raindrops to form a rainbow. By coincidence, the tornado appears to end right over the rainbow. Streaks in the image are hail being swept about by the high swirling winds. Over 1,000 tornadoes, the most violent type of storm known, occur on Earth every year, many in tornado alley. If you see a tornado while driving, do not try to outrun it -- park your car safely, go to a storm cellar, or crouch under steps in a basement. Follow APOD on: Facebook, Google Plus, or Twitter

Solar active region AR2192 was the largest recorded sunspot group of the last 24 years. Before rotating off the Earth-facing side of the Sun at the end of October, it produced a whopping six energetic X-class flares. Its most intense flare was captured on October 24 in this stunning view from the orbiting Solar Dynamics Observatory. The scene is a color combination of images made at three different wavelengths of extreme ultraviolet light; 193 angstroms shown in blue, 171 angstroms in white, and 304 angstroms in red. The emission, from highly ionized Iron and Helium atoms, traces magnetic field lines looping through the hot plasma of the Sun's outer chromosphere and corona. Beneath, the cooler solar photosphere appears dark at extreme ultraviolet wavelengths. The exceptionally sharp composite image has been processed with a new mathematical algorithm (NAFE) that adapts to noise and brightness in extreme ultraviolet image data to reliably enhance small details.