NASA Latest Images ( from 06-Feb-2016 to 26-Feb-2016 )

USA's Northeast Megalopolis from Space
Image Credit: NASA, International Space Station
Explanation: Can you identify a familiar area in the northeast USA just from nighttime lights? It might be possible because many major cities are visible, including (right to left) New York, Philadelphia, Baltimore, Washington, Richmond and Norfolk -- Boston of the USA's Northeast megalopolis is not pictured. The featured image was taken in 2012 from the International Space Station. In the foreground are two Russian cargo ships with prominent solar panels. This Northeast megalopolis of the USA contains almost 20 percent of the people of the USA but only about 2 percent of the land area. Also known also as the Northeast Corridor and part of the Eastern Seaboard, about 10 percent of the world's largest companies are headquartered here. The near continuity of the lights seem to add credence to the 1960s-era prediction that the entire stretch is evolving into one continuous city.

A Supernova through Galaxy Dust
Image Credit: NASA, ESA, and the Hubble Heritage (STScI/AURA);
Inset Image: Howard Hedlund & Dave Jurasevich, Las Campanas Obs.
Explanation: Telescopes around the world are tracking a bright supernova that occurred in a nearby dusty galaxy. The powerful stellar explosion was first noted earlier this month. The nearby galaxy is the photogenic Centaurus A, visible with binoculars and known for impressive filaments of light-absorbing dust that cross its center. Cen A is featured here in a high-resolution archival Hubble Space Telescope image, with an inset image featuring the supernova taken from the ground only two days after discovery. Designated SN2016adj, the supernova is highlighted with crosshairs in the inset, appearing just to the left of a bright foreground star in our Milky Way Galaxy. This supernova is currently thought to be of Type IIb, a stellar-core-collapse supernova, and is of high interest because it occurred so nearby and because it is being seen through a known dust filament. Current and future observations of this supernova may give us new clues about the fates of massive stars and how some elements found on our Earth were formed.

Flying Over Pluto's Moon Charon
Video Credit: NASA, Johns Hopkins U. APL, SwRI, Stuart Robbins
Explanation: Given some poetic license, there is now scientific evidence that hell has frozen over. To start, Greek mythology holds that Charon is the ferryman of the underworld. Next, recent analysis of data taken by the robotic New Horizons spacecraft that shot past Charon -- the namesake that is the largest moon of Pluto -- in July now indicates that the cause of the huge chasm that runs across the 1200-km moon was that a huge internal sea froze. And since water expands when it freezes, the already hardened outer crust could not contain it and cracked. To better picture the crack, a fanciful journey over some of Charon's has been digitally created from collected images. The featured video starts by showing the Dark Polar Deposit (dubbed Mordor) near Charon's north pole and then flies over the dwarf-planet-wide canyon. Last, the video shows a much-debated protuberance called Moated Mountain. Understanding the history of Pluto and Charon is helping humanity to better understand both the friendliest and more forbidding places in the early Solar System from which Earth formed and life somehow emerged.

M82: Galaxy with a Supergalactic Wind
Image Credit: NASA, ESA, The Hubble Heritage Team, (STScI/AURA)
Acknowledgement: M. Mountain (STScI), P. Puxley (NSF), J. Gallagher (U. Wisconsin)
Explanation: What's lighting up the Cigar Galaxy? M82, as this irregular galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81. This doesn't fully explain the source of the red-glowing outwardly expanding gas, however. Evidence indicates that this gas is being driven out by the combined emerging particle winds of many stars, together creating a galactic superwind. The featured photographic mosaic highlights a specific color of red light strongly emitted by ionized hydrogen gas, showing detailed filaments of this gas. The filaments extend for over 10,000 light years. The 12-million light-year distant Cigar Galaxy is the brightest galaxy in the sky in infrared light, and can be seen in visible light with a small telescope towards the constellation of the Great Bear (Ursa Major).

Where Your Shadow Has Company
Poster Illustration Credit: NASA, JPL, Exoplanet Travel Bureau
Explanation: Want to take a relaxing interstellar vacation? Consider visiting Kepler-16b, a world in a binary star system. In fact Kepler-16b is the first discovered circumbinary planet. It was detected in a wide 229 day orbit around a close pair of cool, low-mass stars some 200 light-years away. The parent stars eclipse one another in their orbits, observed as a periodic dimming of starlight. But Kepler-16b itself was discovered by following the additional very slight dimming produced during its transits. Like sci-fi planet Tatooine of Star Wars fame, two suns would set over its horizon. Still, Kepler-16b is probably not a Tatooine-like terrestrial desert world. Instead, Kepler-16b is thought to be a cold, uninhabitable planet with about the mass of Saturn and a gaseous surface ... so plan to dress accordingly. Or, choose another Visions of the Future vacation destination.

Star Forming Region S106
Image Credit: NASA, ESA, Hubble Legacy Archive; Processed & Copyright: Brandon Pimenta
Explanation: Massive star IRS 4 is beginning to spread its wings. Born only about 100,000 years ago, material streaming out from this newborn star has formed the nebula dubbed Sharpless 2-106 Nebula (S106), featured here. A large disk of dust and gas orbiting Infrared Source 4 (IRS 4), visible in brown near the image center, gives the nebula an hourglass or butterfly shape. S106 gas near IRS 4 acts as an emission nebula as it emits light after being ionized, while dust far from IRS 4 reflects light from the central star and so acts as a reflection nebula. Detailed inspection of a recent infrared image of S106 reveal hundreds of low-mass brown dwarf stars lurking in the nebula's gas. S106 spans about 2 light-years and lies about 2000 light-years away toward the constellation of the Swan (Cygnus).

White Rock Fingers on Mars
Image Credit: THEMIS, Mars Odyssey Team, ASU, JPL, NASA
Explanation: What caused this unusual light rock formation on Mars? Intrigued by the possibility that they could be salt deposits left over as an ancient lakebed dried-up, detailed studies of these fingers now indicate a more mundane possibility: volcanic ash. Studying the exact color of the formation indicated the possible volcanic origin. The light material appears to have eroded away from surrounding area, indicating a very low-density substance. The stark contrast between the rocks and the surrounding sand is compounded by the unusual darkness of the sand. The featured picture was taken with the Thermal Emission Imaging System on the Mars Odyssey, the longest serving spacecraft currently orbiting Mars. The image spans about 10 kilometers inside a larger crater.

Yutu on a Little Planet
Image Credit: Chinese Academy of Sciences, Chinese National Space Administration,
Emily Lakdawalla (Planetary Society) - Stitched by: Andrew Bodrov
Explanation: Tracks lead to a small robot perched near the top of this bright little planet. Of course, the planet is really the Moon. The robot is the desk-sized Yutu rover, leaving its looming Chang'e 3 lander after a after a mid-December 2013 touch down in the northern Mare Imbrium. The little planet projection is a digitally warped and stitched mosaic of images from the lander's terrain camera covering 360 by 180 degrees. Ultimately traveling over 100 meters, Yutu came to a halt in January 2014. The lander's instruments are still working though, after more than two years on the lunar surface. Meanwhile, an interactive panoramic version of this little planet is available here.

Two Black Holes Merge
Simulation Credit: Simulating eXtreme Spacetimes Project
Explanation: Just press play to watch two black holes merge. Inspired by the first direct detection of gravitational waves by LIGO, this simulation video plays in slow motion but would take about one third of a second if run in real time. Set on a cosmic stage the black holes are posed in front of stars, gas, and dust. Their extreme gravity lenses the light from behind them into Einstein rings as they spiral closer and finally merge into one. The otherwise invisible gravitational waves generated as the massive objects rapidly coalesce cause the visible image to ripple and slosh both inside and outside the Einstein rings even after the black holes have merged. Dubbed GW150914, the gravitational waves detected by LIGO are consistent with the merger of 36 and 29 solar mass black holes at a distance of 1.3 billion light-years. The final, single black hole has 62 times the mass of the Sun, with the remaining 3 solar masses converted into energy in gravitational waves.

Galaxies in the River
Image Credit & Copyright: CEDIC Team - Processing: Markus Blauensteiner
Explanation: Large galaxies grow by eating small ones. Even our own galaxy practices galactic cannibalism, absorbing small galaxies that get too close and are captured by the Milky Way's gravity. In fact, the practice is common in the universe and illustrated by this striking pair of interacting galaxies from the banks of the southern constellation Eridanus, The River. Located over 50 million light years away, the large, distorted spiral NGC 1532 is seen locked in a gravitational struggle with dwarf galaxy NGC 1531 (right of center), a struggle the smaller galaxy will eventually lose. Seen edge-on, spiral NGC 1532 spans about 100,000 light-years. Nicely detailed in this sharp image, the NGC 1532/1531 pair is thought to be similar to the well-studied system of face-on spiral and small companion known as M51.

The Rise and Fall of Supernova 2015F
Video Credit & Copyright: Changsu Choi & Myungshin Im (Seoul National University)
Explanation: Sit back and watch a star explode. The actual supernova occurred back when dinosaurs roamed the Earth, but images of the spectacular event began arriving last year. Supernova 2015F was discovered in nearby spiral galaxy NGC 2442 by Berto Monard in 2015 March and was unusually bright -- enough to be seen with only a small telescope. The pattern of brightness variation indicated a Type Ia supernova -- a type of stellar explosion that results when an Earth-size white dwarf gains so much mass that its core crosses the threshold of nuclear fusion, possibly caused by a lower mass white-dwarf companion spiraling into it. Finding and tracking Type Ia supernovae are particularly important because their intrinsic brightness can be calibrated, making their apparent brightness a good measure of their distance -- and hence useful toward calibrating the distance scale of the entire universe. The featured video tracked the stellar disruption from before explosion images arrived, as it brightened, and for several months as the fission-powered supernova glow faded. The remnants of SN2015F are now too dim to see without a large telescope. Just yesterday, however, the night sky lit up once again, this time with an even brighter supernova in an even closer galaxy: Centaurus A.

Source - NASA