At the top right, large spiral galaxy NGC 1055 joins spiral Messier 77 in this sharp cosmic view toward the aquatic constellation Cetus. The narrowed, dusty appearance of edge-on spiral NGC 1055 contrasts nicely with the face-on view of M77's bright nucleus and spiral arms. Both over 100,000 light-years across, the pair are dominant members of a small galaxy group about 60 million light-years away. At that estimated distance, M77 is one of the most remote objects in Charles Messier's catalog and is separated from fellow island universe NGC 1055 by at least 500,000 light-years. The field of view is about the size of the full Moon on the sky and includes colorful foreground Milky Way stars (with diffraction spikes) along with more distant background galaxies.

Comet Lovejoy, C/2014 Q2, is framed like a cosmic Christmas tree with starry decorations in this colorful telescopic portrait, snapped on December 16th. Its lovely coma is tinted green by diatomic C2 gas fluorescing in sunlight. Discovered in August of this year, this Comet Lovejoy is currently sweeping north through the constellation Columba, heading for Lepus south of Orion and bright enough to offer good binocular views. Not its first time through the inner Solar System, this Comet Lovejoy will pass closest to planet Earth on January 7, while its perihelion (closest point to the Sun) will be on January 30. Of course, planet Earth's own 2015 perihelion passage is scheduled for January 4. A long period comet, this Comet Lovejoy should return again ... in about 8,000 years.

Comet Lovejoy, C/2014 Q2, is framed like a cosmic Christmas tree with starry decorations in this colorful telescopic portrait, snapped on December 16th. Its lovely coma is tinted green by diatomic C2 gas fluorescing in sunlight. Discovered in August of this year, this Comet Lovejoy is currently sweeping north through the constellation Columba, heading for Lepus south of Orion and bright enough to offer good binocular views. Not its first time through the inner Solar System, this Comet Lovejoy will pass closest to planet Earth on January 7, while its perihelion (closest point to the Sun) will be on January 30. Of course, planet Earth's own 2015 perihelion passage is scheduled for January 4. A long period comet, this Comet Lovejoy should return again ... in about 8,000 years.

To some, this nebula looks like the head of a fish. However, this colorful cosmic portrait really features glowing gas and obscuring dust clouds in IC 1795, a star forming region in the northern constellation Cassiopeia. The nebula's colors were created by adopting the Hubble false-color palette for mapping narrow emission from oxygen, hydrogen, and sulfur atoms to blue, green and red colors, and further blending the data with images of the region recorded through broadband filters. Not far on the sky from the famous Double Star Cluster in Perseus, IC 1795 is itself located next to IC 1805, the Heart Nebula, as part of a complex of star forming regions that lie at the edge of a large molecular cloud. Located just over 6,000 light-years away, the larger star forming complex sprawls along the Perseus spiral arm of our Milky Way Galaxy. At that distance, this picture would span about 70 light-years across IC 1795.

To some, this nebula looks like the head of a fish. However, this colorful cosmic portrait really features glowing gas and obscuring dust clouds in IC 1795, a star forming region in the northern constellation Cassiopeia. The nebula's colors were created by adopting the Hubble false-color palette for mapping narrow emission from oxygen, hydrogen, and sulfur atoms to blue, green and red colors, and further blending the data with images of the region recorded through broadband filters. Not far on the sky from the famous Double Star Cluster in Perseus, IC 1795 is itself located next to IC 1805, the Heart Nebula, as part of a complex of star forming regions that lie at the edge of a large molecular cloud. Located just over 6,000 light-years away, the larger star forming complex sprawls along the Perseus spiral arm of our Milky Way Galaxy. At that distance, this picture would span about 70 light-years across IC 1795.

These high cliffs occur on the surface of a comet. They were discovered to be part of the dark nucleus of Comet Churyumov–Gerasimenko (CG) by Rosetta, a robotic spacecraft launched by ESA which began orbiting the comet in early August. The ragged cliffs, as featured here, were imaged by Rosetta about two weeks ago. Although towering about one kilometer high, the low surface gravity of Comet CG would likely make a jump from the cliffs, by a human, survivable. At the foot of the cliffs is relatively smooth terrain dotted with boulders as large as 20 meters across. Data from Rosetta indicates that the ice in Comet CG has a significantly different deuterium fraction -- and hence likely a different origin -- than the water in Earth's oceans. The Rosetta spacecraft is scheduled to continue to accompany the comet as it makes its closest approach to the Sun in 2015 August.

These high cliffs occur on the surface of a comet. They were discovered to be part of the dark nucleus of Comet Churyumov–Gerasimenko (CG) by Rosetta, a robotic spacecraft launched by ESA which began orbiting the comet in early August. The ragged cliffs, as featured here, were imaged by Rosetta about two weeks ago. Although towering about one kilometer high, the low surface gravity of Comet CG would likely make a jump from the cliffs, by a human, survivable. At the foot of the cliffs is relatively smooth terrain dotted with boulders as large as 20 meters across. Data from Rosetta indicates that the ice in Comet CG has a significantly different deuterium fraction -- and hence likely a different origin -- than the water in Earth's oceans. The Rosetta spacecraft is scheduled to continue to accompany the comet as it makes its closest approach to the Sun in 2015 August.

What's creating methane on Mars? Recent measurements from the robotic Curiosity rover currently rolling across Mars indicate a surprising 10-fold increase in atmospheric methane between measurements only months apart. Life is a major producer of methane on Earth, and so speculation is rampant that some sort of life -- possibly microbial life -- is creating methane beneath the surface of Mars. Other possibilities do exist, though, with a leading model being the sudden release of methane produced by the mixing of specific soil chemicals with underground water. Proposed origins of Martian methane are depicted in the featured illustration. The origin of Mars' methane is a very active area of research, with missions like Curiosity and India's Mars Orbiter Mission searching for clues by measuring methane abundance changes and possible byproducts of different methane-producing processes.

What's creating methane on Mars? Recent measurements from the robotic Curiosity rover currently rolling across Mars indicate a surprising 10-fold increase in atmospheric methane between measurements only months apart. Life is a major producer of methane on Earth, and so speculation is rampant that some sort of life -- possibly microbial life -- is creating methane beneath the surface of Mars. Other possibilities do exist, though, with a leading model being the sudden release of methane produced by the mixing of specific soil chemicals with underground water. Proposed origins of Martian methane are depicted in the featured illustration. The origin of Mars' methane is a very active area of research, with missions like Curiosity and India's Mars Orbiter Mission searching for clues by measuring methane abundance changes and possible byproducts of different methane-producing processes.

Today the solstice occurs at 23:03 Universal Time, the Sun reaching its southernmost declination in planet Earth's sky. Of course, the December solstice marks the beginning of winter in the northern hemisphere and summer in the south. When viewed from northern latitudes, and as shown in the above horizontally compressed image, the Sun will make its lowest arc through the sky along the southern horizon. So in the north, the solstice day has the shortest length of time between sunrise and sunset and fewest hours of daylight. This striking composite image follows the Sun's path through the December solstice day of 2005 in a beautiful blue sky, looking down the Tyrrhenian Sea coast from Santa Severa toward Fiumicino, Italy. The view covers about 115 degrees in 43 separate, well-planned exposures from sunrise to sunset. Follow APOD on: Facebook, Google Plus, or Twitter

Have you seen a panorama from another world lately? Assembled from high-resolution scans of the original film frames, this one sweeps across the magnificent desolation of the Apollo 11 landing site on the Moon's Sea of Tranquility. Taken by Neil Armstrong looking out his window of the Eagle Lunar Module, the frame at the far left (AS11-37-5449) is the first picture taken by a person on another world. Toward the south, thruster nozzles can be seen in the foreground on the left, while at the right, the shadow of the Eagle is visible toward the west. For scale, the large, shallow crater on the right has a diameter of about 12 meters. Frames taken from the Lunar Module windows about an hour and a half after landing, before walking on the lunar surface, were intended to initially document the landing site in case an early departure was necessary.

The 1970s are sometimes ignored by astronomers, like this beautiful grouping of reflection nebulae in Orion - NGC 1977, NGC 1975, and NGC 1973 - usually overlooked in favor of the substantial glow from the nearby stellar nursery better known as the Orion Nebula. Found along Orion's sword just north of the bright Orion Nebula complex, these reflection nebulae are also associated with Orion's giant molecular cloud about 1,500 light-years away, but are dominated by the characteristic blue color of interstellar dust reflecting light from hot young stars. In this sharp color image a portion of the Orion Nebula appears along the bottom border with the cluster of reflection nebulae at picture center. NGC 1977 stretches across the field just below center, separated from NGC 1973 (above right) and NGC 1975 (above left) by dark regions laced with faint red emission from hydrogen atoms. Taken together, the dark regions suggest to many the shape of a running man.