What’s the closest active galaxy to planet Earth? That would be Centaurus A, only 11 million light-years distant. Spanning over 60,000 light-years, the peculiar elliptical galaxy is also known as NGC 5128. Forged in a collision of two otherwise normal galaxies, Centaurus A’s fantastic jumble of young blue star clusters, pinkish star forming regions, and imposing dark dust lanes are seen here in remarkable detail. The colorful galaxy portrait is a composite of image data from space- and ground-based telescopes large and small. Near the galaxy’s center, left over cosmic debris is steadily being consumed by a central black hole with a billion times the mass of the Sun. As in other active galaxies, that process generates the radio, X-ray, and gamma-ray energy radiated by Centaurus A.

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There she blows! A dramatic demonstration of how short-lived some comet jets can be was documented in late July by the robotic Rosetta spacecraft orbiting the nucleus of Comet 67P/Churyumov-Gerasimenko. The featured animation depicts changes in the rotating comet with three illuminating stills. Although the first frame shows nothing unusual, the second frame shows a sudden strong jet shooting off the 67P‘s surface only 20 minutes later, while the third frame — taken 20 minutes after that — shows but a slight remnant of the once-active jet. As comets near the Sun, they can produce long and beautiful tails that stream across the inner Solar System. How comet jets produce these tails is a topic of research — helped by images like this. Another recent Rosetta measurement indicates that the water on Earth could not have come from comets like 67P because of significant differences in impurities. Comet 67P spans about four kilometers, orbits the Sun between Earth and Jupiter, and has been the home for ESA‘s Rosetta spaceship since 2014 August. Rosetta is currently scheduled to make a slow crash onto Comet 67P’s surface in late 2016.

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The Pelican Nebula is slowly being transformed. IC 5070, the official designation, is divided from the larger North America Nebula by a molecular cloud filled with dark dust. The Pelican, however, receives much study because it is a particularly active mix of star formation and evolving gas clouds. The featured picture was produced in three specific colors — light emitted by sulfur, hydrogen, and oxygen — that can help us to better understand these interactions. The light from young energetic stars is slowly transforming the cold gas to hot gas, with the advancing boundary between the two, known as an ionization front, visible in bright orange on the right. Particularly dense tentacles of cold gas remain. Millions of years from now this nebula might no longer be known as the Pelican, as the balance and placement of stars and gas will surely leave something that appears completely different.

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What’s happening to that meteor? A few days ago, a bright fireball was photographed from the Alps mountain range in Switzerland as it blazed across the sky. The fireball, likely from the Taurids meteor shower, was notable not only for how bright it was, but for the rare orange light it created that lingered for several minutes. Initially, the orange glow made it seem like the meteor trail was on fire. However, the orange glow, known as a persistent train, originated neither from fire nor sunlight-reflecting smoke. Rather, the persistent train‘s glow emanated from atoms in the Earth’s atmosphere in the path of the meteor — atoms that had an electron knocked away and emit light during reacquisition. Persistent trains often drift, so that the long 3-minute exposure actually captured the initial wind-blown displacement of these bright former ions. The featured image was acquired when trying to image the famous Orion Nebula, visible on the upper left. The bright blue star Rigel, part of the constellation of Orion, is visible to the right. This week the fireball-rich Taurids meteor shower continues to be active even though it has passed its peak, while the more active Leonids meteor shower is just peaking.

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There was a shower over Monument Valley — but not water. Meteors. The featured image — actually a composite of six exposures of about 30 seconds each — was taken in 2001, a year when there was a very active Leonids shower. At that time, Earth was moving through a particularly dense swarm of sand-sized debris from Comet Tempel-Tuttle, so that meteor rates approached one visible streak per second. The meteors appear parallel because they all fall to Earth from the meteor shower radiant — a point on the sky towards the constellation of the Lion (Leo). The yearly Leonids meteor shower peaks again this week. Although the Moon’s glow should not obstruct the visibility of many meteors, this year’s shower will peak with perhaps 15 meteors visible in an hour, a rate which is good but not expected to rival the 2001 Leonids. By the way — how many meteors can you identify in the featured image?

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Long shadows are cast by a low Sun across this rugged looking terrain. Captured by New Horizons, the scene is found just south of the southern tip Sputnik Planum, the informally named smooth, bright heart region of Pluto. Centered is a feature provisionally known as Wright Mons, a broad, tall mountain, about 150 kilometers across and 4 kilometers high, with a 56 kilometer wide, deep summit depression. Of course, broad mountains with central craters are found elsewhere in the Solar System, like Mauna Loa on planet Earth and Olympus Mons on Mars. In fact, New Horizons scientists announced the striking similarity of Pluto’s Wright Mons, and nearby Piccard Mons, to large shield volcanoes strongly suggests the two could be giant cryovolcanoes that once erupted molten ice from the interior of the cold, distant world.

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This telescopic close-up shows off the otherwise faint emission nebula IC 410. It also features two remarkable inhabitants of the cosmic pond of gas and dust below and right of center, the tadpoles of IC 410. Partly obscured by foreground dust, the nebula itself surrounds NGC 1893, a young galactic cluster of stars. Formed in the interstellar cloud a mere 4 million years ago, the intensely hot, bright cluster stars energize the glowing gas. Composed of denser cooler gas and dust, the tadpoles are around 10 light-years long and are likely sites of ongoing star formation. Sculpted by winds and radiation from the cluster stars, their heads are outlined by bright ridges of ionized gas while their tails trail away from the cluster’s central region. IC 410 lies some 10,000 light-years away, toward the nebula-rich constellation Auriga.

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On November 8, a waning crescent Moon joined the continuing parade of planets in Earth’s early morning skies. Captured here from Amboseli National Park, Kenya, even the overexposed moonlight can’t washout brilliant Venus though, lined up near the ecliptic plane with faint Mars and bright Jupiter above. As if Moon and planets aren’t enough, a comparably bright Taurid meteor also streaks through the scene. In fact November’s Taurid meteor showers have had a high proportion of bright fireballs. Apparently streaming from radiants in Taurus, the meteors are caused by our fair planet’s annual passage through debris from Comet 2P/Encke. The comet’s dust grains are catching up with Earth’s atmosphere at a relatively low speed of about 27 kilometers per second.

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What is that unusual light in the sky? A common question, this particular light was not only bright but moving and expanding. It appeared just as the astrophotographer and his friend were photographing the Golden Gate Bridge in San Francisco, California against a more predictable night sky. They were not alone in seeing this unusual display — at least hundreds of people in California reported a similar sight. The consensus of experienced sky observers was that the plume resulted from a rocket launch — an explanation that was soon confirmed as an unpublicized test of a submarine-launched, unarmed, Trident II D5 nuclear missile. Such tests are not uncommon but do not usually occur just after sunset near a major metropolitan area — when they are particularly noticeable to many people. Were plume images not posted to the Internet and quickly identified, such a sky spectacle might have been understood by some to be associated with more grandiose — but incorrect — explanations.

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Is star AE Aurigae on fire? No. Even though AE Aurigae is named the flaming star, the surrounding nebula IC 405 is named the Flaming Star Nebula, and the region appears to have the color of fire, there is no fire. Fire, typically defined as the rapid molecular acquisition of oxygen, happens only when sufficient oxygen is present and is not important in such high-energy, low-oxygen environments such as stars. The material that appears as smoke is mostly interstellar hydrogen, but does contain smoke-like dark filaments of carbon-rich dust grains. The bright star AE Aurigae, visible toward the right near the nebula’s center, is so hot it is blue, emitting light so energetic it knocks electrons away from surrounding gas. When a proton recaptures an electron, light is emitted, as seen in the surrounding emission nebula. Pictured above, the Flaming Star nebula lies about 1,500 light years distant, spans about 5 light years, and is visible with a small telescope toward the constellation of the Charioteer (Auriga).

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