In Greek myth Prometheus was a Titan, known for bringing fire from Mount Olympus. But in modern times the name is given to a small moon of Saturn, orbiting just inside Saturn’s F ring. In a complex interaction, the tiny potato-shaped moon interacts with the icy ring particles creating structures along the F ring still not fully understood. One of the highest resolution views of Prometheus, this image of its pocked surface posing with the thin F ring in the background was taken during the Cassini spacecraft’s close approach on December 6, 2015. Prometheus is about 86 kilometers (50 miles) across.

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A mere 2.5 million light-years away, the Andromeda Galaxy, also known as M31, really is just next door as large galaxies go. In this (inset) scan, image data from NASA’s Nuclear Spectrosopic Telescope Array has yielded the best high-energy X-ray view yet of our large neighboring spiral, revealing some 40 extreme sources of X-rays, X-ray binary star systems that contain a black hole or neutron star orbiting a more normal stellar companion. In fact, larger Andromeda and our own Milky Way are the most massive members of the local galaxy group. Andromeda is close enough that NuSTAR can examine its population of X-ray binaries in detail, comparing them to our own. The background image of Andromeda was taken by NASA’s Galaxy Evolution Explorer in energetic ultraviolet light.

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This timely, telescopic, two panel mosaic spans about 10 full moons across planet Earth’s predawn skies. Recorded as the year began from Tenerife, Canary Islands, near the top of the frame are the faint coma and tail of Comet Borrelly (P/19). A comet with a seven year orbital period, Borrelly’s nucleus was visited by the ion propelled spacecraft Deep Space 1 near the beginning of the 21st century. Anchoring the scene at the bottom is brilliant star Arcturus (Alpha Bootes) and Comet Catalina (C/2013 US10) a first time visitor from the Oort Cloud. Catalina’s yellowish dust tail extends below and right. Buffeted by winds and storms from the Sun, the comet’s complex ion tail sweeps up and toward the right, across most of the field of view. Remarkably, one of the composition’s 30 second exposure subframes also caught the trail of a bright meteor, slashing toward the left between comets and bright star.

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The majestic Lagoon Nebula is filled with hot gas and the home for many young stars. Spanning 100 light years across while lying only about 5000 light years distant, the Lagoon Nebula is so big and bright that it can be seen without a telescope toward the constellation of the Archer (Sagittarius). Many bright stars are visible from NGC 6530, an open cluster that formed in the nebula only several million years ago. The greater nebula, also known as M8 and NGC 6523, is named “Lagoon” for the band of dust seen to the right of the open cluster’s center. The featured image was taken in the light emitted by Hydrogen (shown in brown), Sulfur (red), and Oxygen (blue) and displayed in enhanced color. The featured picture is a newly processed panorama of M8, capturing twice the diameter of the Full Moon. Star formation continues in the Lagoon Nebula as witnessed by the many globules that exist there.

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On the Moon, the Earth never rises — or sets. If you were to sit on the surface of the Moon, you would see the Earth just hang in the sky. This is because the Moon always keeps the same side toward the Earth. Curiously, the featured image does picture the Earth setting over a lunar edge. This was possible because the image was taken from a spacecraft orbiting the Moon – specifically the Lunar Reconnaissance Orbiter (LRO). In fact, LRO orbits the Moon so fast that, from the spacecraft, the Earth appears to set anew about every two hours. The featured image captured one such Earthset about three months ago. By contrast, from the surface of the Earth, the Moon sets about once a day — with the primary cause being the rotation of the Earth. LRO was launched in 2009 and, while creating a detailed three dimensional map of the Moon’s surface, is also surveying the Moon for water and possible good landing spots for future astronauts.

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On some nights, the sky is the best show in town. On this night, the sky was not only the best show in town, but a composite image of the sky won an international competition for landscape astrophotography. The featured winning image was taken in 2011 over Jökulsárlón, the largest glacial lake in Iceland. The photographer combined six exposures to capture not only two green auroral rings, but their reflections off the serene lake. Visible in the distant background sky is the band of our Milky Way Galaxy and the Andromeda galaxy. A powerful coronal mass ejection from the Sun caused auroras to be seen as far south as Wisconsin, USA. Solar activity over the past week has resulted in auroras just over the past few days.

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Triggered by the impact of a coronal mass ejection on New Year’s eve, a moderate geomagnetic storm brought a celebration of sky lights to planet Earth’s high latitudes yesterday. In this New Year’s nightscape, the shimmering reddish curtains of aurora australis along a southern horizon are captured over Morgiana, SW Victoria, Australia. Of course, more permanent jewels of the southern skies are on the scene. The southern Milky Way, Alpha and Beta Centauri, and bright stars of the Southern Cross are on the left. In silhouette, branches of the large foreground tree stretch across the Milky Way’s satellite galaxies, the Large and Small Magellanic clouds. The bright star framed near the tips of tree branches at right is Achernar. Alpha star of the constellation Eridanus, Achernar is sometimes known as the southern end of the river.

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A new year’s treat for binoculars, as 2016 begins Comet Catalina (C/2013 US10) now sweeps through planet Earth’s predawn skies near bright Arcturus, alpha star of Bootes. But this telescopic mosaic from December 21 follows the pretty tails of the comet across a field of view as wide as 10 full moons. The smattering of distant galaxies and faint stars in the background are in the constellation Virgo. Trailing behind the comet’s orbit, Catalina’s dust tail fans out below and left in the frame. Its ion tail is angled toward the top right, away from the Sun and buffeted by the solar wind. On January 17, the outward bound visitor from the Oort Cloud will make its closest approach to Earth, a mere 110 million kilometers away, seen near bright stars along the handle of the Big Dipper.

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A southern exposure and striking symmetry made Lulworth Cove, along the Jurassic Coast of England, planet Earth a beautiful setting during December’s Solstice. Five frames in this dramatic composite view follow the lowest arc of the Sun, from sunrise to sunset, during the shortest day of the year. The solstice arc spans about 103 degrees at this northern latitude. Of course, erosion by wave action has produced the cove’s remarkable shape in the coastal limestone layers. The cove’s narrow entrance is responsible, creating a circular wave diffraction pattern. The wave pattern is made clearer by the low solstice Sun.

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This interstellar canine is formed of cosmic dust and gas interacting with the energetic light and winds from hot young stars. The shape, visual texture, and color, combine to give the region the popular name Fox Fur Nebula. The characteristic blue glow on the left is dust reflecting light from the bright star S Mon, the bright star just below the top edge of the featured image. Textured red and black areas are a combination of the cosmic dust and reddish emission from ionized hydrogen gas. S Mon is part of a young open cluster of stars, NGC 2264, located about 2,500 light years away toward the constellation of the Unicorn (Monoceros).

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