W5: The Soul of Star Formation W5: The Soul of Star Formation

Where do stars form? Many times, stars form in energetic regions where gas and dark dust are pushed around in chaotic mayhem. Pictured, bright massive stars near the center of W5, the Soul Nebula, are exploding and emitting ionizing light and energetic winds. The outward-moving light and gas push away and evaporate much surrounding gas and dust, but leave pillars of gas behind dense protective knots. Inside these knots, though, stars also form. The featured image highlights the inner sanctum of W5, an arena spanning about 1,000 light years that is rich in star forming pillars. The Soul Nebula, also cataloged as IC 1848, lies about 6,500 light years away toward the constellation of the Queen of Aethopia (Cassiopeia). Likely, in few hundred million years, only a cluster of the resulting stars will remain. Then, these stars will drift apart. via NASA http://ift.tt/2fxUBRk

Verona Rupes: Tallest Known Cliff in the Solar System Verona Rupes: Tallest Known Cliff in the Solar System

Could you survive a jump off the tallest cliff in the Solar System? Quite possibly. Verona Rupes on Uranus' moon Miranda is estimated to be 20 kilometers deep -- ten times the depth of the Earth's Grand Canyon. Given Miranda's low gravity, it would take about 12 minutes for a thrill-seeking adventurer to fall from the top, reaching the bottom at the speed of a racecar -- about 200 kilometers per hour. Even so, the fall might be survivable given proper airbag protection. The featured image of Verona Rupes was captured by the passing Voyager 2 robotic spacecraft in 1986. How the giant cliff was created remains unknown, but is possibly related to a large impact or tectonic surface motion. via NASA http://ift.tt/2fnUdoD

East to West, Light and Shadow East to West, Light and Shadow

On this November morning an old crescent Moon and morning star rise just before the Sun in a wide panoramic skyscape from Kenya's Amboseli National Park. Still below the limbs of an acacia tree and the eastern horizon, the Sun's position is easy to find though. It's marked at the left by the subtle convergence of light and shadow in the dawn sky. Known as crepuscular rays, the warm-colored rays of sunlight are outlined by shadows cast by unseen clouds near the horizon. Arcing above the profile of Mount Kilimanjaro, toward the right the rays of light and shadow converge at the western horizon. There known as anti-crepuscular rays, they indicate the point opposite the rising sun. The cloud shadows are very nearly parallel, but converge toward the distant horizons because of perspective. via NASA http://ift.tt/2gwPjCY

Apollo 17 VIP Site Anaglyph Apollo 17 VIP Site Anaglyph

Get out your red/blue glasses and check out this stereo scene from Taurus-Littrow valley on the Moon! The color anaglyph features a detailed 3D view of Apollo 17's Lunar Rover in the foreground -- behind it lies the Lunar Module and distant lunar hills. Because the world was going to be able to watch the Lunar Module's ascent stage liftoff via the rover's TV camera, this parking place was also known as the VIP Site. In December of 1972, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt spent about 75 hours on the Moon, while colleague Ronald Evans orbited overhead. The crew returned with 110 kilograms of rock and soil samples, more than from any of the other lunar landing sites. Cernan and Schmitt are still the last to walk (or drive) on the Moon. via NASA http://ift.tt/2fyv60M

Ring Scan Ring Scan

Scroll right and you can cruise along the icy rings of Saturn. This high resolution scan is a mosaic of images presented in natural color. The images were recorded in May 2007 over about 2.5 hours as the Cassini spacecraft passed above the unlit side of the rings. To help track your progress, major rings and gaps are labeled along with the distance from the center of the gas giant in kilometers. The alphabetical designation of Saturn's rings is historically based on their order of discovery; rings A and B are the bright rings separated by the Cassini division. In order of increasing distance from Saturn, the seven main rings run D,C,B,A,F,G,E. (Faint, outer rings G and E are not imaged here.) Four days from now, on November 29, Cassini will make a close flyby of Saturn's moon Titan and use the large moon's gravity to nudge the spacecraft into a series of 20 daring, elliptical, ring-grazing orbits. Diving through the ring plane just 11,000 kilometers outside the F ring (far right) Cassini's first ring-graze will be on December 4. via NASA http://ift.tt/2fbgea1

Plutos Sputnik Planum Plutos Sputnik Planum

Is there an ocean below Sputnik Planum on Pluto? The unusually smooth 1000-km wide golden expanse, visible in the featured image from New Horizons, appears segmented into convection cells. But how was this region created? One hypothesis now holds the answer to be a great impact that stirred up an underground ocean of salt water roughly 100-kilometers thick. The featured image of Sputnik Planum, part of the larger heart-shaped Tombaugh Regio, was taken last July and shows true details in exaggerated colors. Although the robotic New Horizons spacecraft is off on a new adventure, continued computer-modeling of this surprising surface feature on Pluto is likely to lead to more refined speculations about what lies beneath. via NASA http://ift.tt/2ghUTco

NGC 4414: A Flocculent Spiral Galaxy NGC 4414: A Flocculent Spiral Galaxy

How much mass do flocculent spirals hide? The featured true color image of flocculent spiral galaxy NGC 4414 was taken with the Hubble Space Telescope to help answer this question. The featured image was augmented with data from the Sloan Digital Sky Survey (SDSS). Flocculent spirals -- galaxies without well-defined spiral arms -- are a quite common form of galaxy, and NGC 4414 is one of the closest. Stars and gas near the visible edge of spiral galaxies orbit the center so fast that the gravity from a large amount of unseen dark matter must be present to hold them together. Understanding the matter and dark matter distribution of NGC 4414 helps humanity calibrate the rest of the galaxy and, by deduction, flocculent spirals in general. Further, calibrating the distance to NGC 4414 helps humanity calibrate the cosmological distance scale of the entire visible universe. via NASA http://ift.tt/2gsbMns

Philadelphia Perigee Full Moon Philadelphia Perigee Full Moon

A supermoon sets over the metropolis of Philadelphia in this twilight snapshot captured on November 14 at 6:21am Eastern Standard Time. Within hours of the Moon's exact full phase, that time does correspond to a lunar perigee or the closest point in the Moon's elliptical orbit around our fair planet. Slightly bigger and brighter at perigee, this Full Moon is still flattened and distorted in appearance by refraction in atmospheric layers along the sight-line near the horizon. Also like more ordinary Full Moons, it shines with the warm color of sunlight. Joined by buildings along the Philadelphia skyline, the perigee full moonlight is reflected in the waters of the mighty Cooper River. via NASA http://ift.tt/2f7q2wQ

Cold Weather Delayed over North America Cold Weather Delayed over North America

Why is it so warm in northern North America? Usually during this time of year -- mid-November -- temperatures average as much as 30 degrees colder. Europe is not seeing a similar warming. One factor appears to be an unusually large and stable high pressure region that has formed over Canada, keeping normally colder arctic air away. Although the fundamental cause of any weather pattern is typically complex, speculation holds that this persistent Canadian anticyclonic region is related to warmer than average sea surface temperatures in the mid-Pacific -- an El Niño -- operating last winter. North Americans should enjoy it while it lasts, though. In the next week or two, cooler-than-average temperatures now being recorded in the mid-Pacific -- a La Niña -- might well begin to affect North American wind and temperature patterns. via NASA http://ift.tt/2gddWar

Super Moon vs Micro Moon Super Moon vs Micro Moon

What is so super about tomorrow's supermoon? Tomorrow, a full moon will occur that appears slightly larger and brighter than usual. The reason is that the Moon's fully illuminated phase occurs within a short time from perigee - when the Moon is its closest to the Earth in its elliptical orbit. Although the precise conditions that define a supermoon vary, tomorrow's supermoon will undoubtedly qualify because it will be the closest, largest, and brightest full moon in over 65 years. One reason supermoons are popular is because they are so easy to see -- just go outside at sunset and watch an impressive full moon rise! Since perigee actually occurs tomorrow morning, tonight's full moon, visible starting at sunset, should also be impressive. Pictured here, a supermoon from 2012 is compared to a micromoon -- when a full Moon occurs near the furthest part of the Moon's orbit -- so that it appears smaller and dimmer than usual. Given many definitions, at least one supermoon occurs each year, with another one coming next month (moon-th). However, a full moon will not come this close to Earth again until 2034. via NASA http://ift.tt/2fvYgeM

Inverted City Beneath Clouds Inverted City Beneath Clouds

How could that city be upside-down? The city, Chicago, was actually perfectly right-side up. The long shadows it projected onto nearby Lake Michigan near sunset, however, when seen in reflection, made the buildings appear inverted. This fascinating, puzzling, yet beautiful image was captured by a photographer in 2014 on an airplane on approach to Chicago's O'Hare International Airport. The Sun can be seen both above and below the cloud deck, with the latter reflected in the calm lake. As a bonus, if you look really closely -- and this is quite a challenge -- you can find another airplane in the image, likely also on approach to the same airport. via NASA http://ift.tt/2frZ98z

NGC 253: Dusty Island Universe NGC 253: Dusty Island Universe

Shiny NGC 253 is one of the brightest spiral galaxies visible, and also one of the dustiest. Some call it the Silver Dollar Galaxy for its appearance in small telescopes, or just the Sculptor Galaxy for its location within the boundaries of the southern constellation Sculptor. First swept up in 1783 by mathematician and astronomer Caroline Herschel, the dusty island universe lies a mere 10 million light-years away. About 70 thousand light-years across, NGC 253 is the largest member of the Sculptor Group of Galaxies, the nearest to our own Local Group of Galaxies. In addition to its spiral dust lanes, tendrils of dust seem to be rising from a galactic disk laced with young star clusters and star forming regions in this sharp color image. The high dust content accompanies frantic star formation, earning NGC 253 the designation of a starburst galaxy. NGC 253 is also known to be a strong source of high-energy x-rays and gamma rays, likely due to massive black holes near the galaxy's center. via NASA http://ift.tt/2f4uaiv

Arp 299: Black Holes in Colliding Galaxies Arp 299: Black Holes in Colliding Galaxies

Is only one black hole spewing high energy radiation -- or two? To help find out, astronomers trained NASA's Earth-orbiting NuSTAR and Chandra telescopes on Arp 299, the enigmatic colliding galaxies expelling the radiation. The two galaxies of Arp 299 have been locked in a gravitational combat for millions of years, while their central black holes will soon do battle themselves. Featured, the high-resolution visible-light image was taken by Hubble, while the superposed diffuse glow of X-ray light was imaged by NuSTAR and shown in false-color red, green, and blue. NuSTAR observations show that only one of the central black holes is seen fighting its way through a region of gas and dust -- and so absorbing matter and emitting X-rays. The energetic radiation, coming only from the galaxy center on the right, is surely created nearby -- but outside -- the central black hole's event horizon. In a billion years or so, only one composite galaxy will remain, and only one central supermassive black hole. Soon thereafter, though, another galaxy may enter the fray. via NASA http://ift.tt/2f8LuDd

Ghost Aurora over Canada Ghost Aurora over Canada

What does this aurora look like to you? While braving the cold to watch the skies above northern Canada early one morning in 2013, a most unusual aurora appeared. The aurora definitely appeared to be shaped like something , but what? Two ghostly possibilities recorded by the astrophotographer were "witch" and "goddess of dawn", but please feel free to suggest your own Halloween-enhanced impressions. Regardless of fantastical pareidolic interpretations, the pictured aurora had a typical green color and was surely caused by the scientifically commonplace action of high energy particles from space interacting with oxygen in Earth's upper atmosphere. In the image foreground, at the bottom, is a frozen Alexandra Falls, while evergreen trees cross the middle. via NASA http://ift.tt/2f4lSIh