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Tuesday, July 31, 2012

Black Widow Nebula


In this Spitzer image, the two opposing bubbles are being formed in opposite directions by the powerful outflows from massive groups of forming stars. The baby stars can be seen as specks of yellow where the two bubbles overlap.

When individual stars form from molecular clouds of gas and dust they produce intense radiation and very strong particle winds. Both the radiation and the stellar winds blow the dust outward from the star creating a cavity or bubble.

In the case of the Black Widow Nebula, astronomers suspect that a large cloud of gas and dust condensed to create multiple clusters of massive star formation. The combined winds from these groups of large stars probably blew out bubbles into the direction of least resistance, forming a double bubble.

Photo credit: NASA/JPL-Caltech/University of Wisconsin

Monday, July 30, 2012

O-Star Vampirism


New research using data from ESO’s Very Large Telescope has revealed that the hottest and brightest stars, which are known as O stars, are often found in close pairs. Many of such binaries transfer mass from one star to another, a kind of stellar vampirism depicted in this artist’s impression.

Illustration credit: ESO/M. Kornmesser/S.E. de Mink

Note: For more information, see The Brightest Stars Don't Live Alone.

Sunday, July 29, 2012

Deforestation of the Amazon Rainforest



This animation shows deforestation of the Amazon Rainforest in the western Brazilian state of Rondônia from 1986 to 2010. While the central area remains green and untouched, squares of light green and brown pop up over time as the forest is cut away.

The animation was created using two cloud-free images: the first from NASA’s Landsat mission in 1986, and the second from the Spanish Deimos mission in 2010. The changes over time were simulated by referring to other satellite data acquired during the 24 years between the two images.

Video credit: ESA/USGS/Deimos Imaging; text credit: ESA/USGS/Deimos Imaging

Friday, July 27, 2012

Tyrrhena Terra


The 1000 × 2000 km area region of Tyrrhena Terra (outlined by the white box in the inset) sits between two regions of low altitude – Hellas Planitia and Isidis Planitia – in Mars' southern hemisphere, as shown in this global topography map. Hydrated minerals were found in 175 locations associated with impact craters in Tyrrhena Terra, such as inside the walls of craters, along crater rims, or in material excavated by the impact. Analysis suggests that these minerals were formed in the presence of water that persisted at depth for an extended period of time.

Map credit: NASA/MOLA Science Team/D. Loizeau et al.

Thursday, July 26, 2012

Extent of Greenland's Ice Cap Melt Over Four Days


Extent of surface melt over Greenland's ice sheet on July 8, 2012 (left) and July 12, 2012 (right). Measurements from three satellites showed that on July 8, about 40 percent of the ice sheet had undergone thawing at or near the surface. In just a few days, the melting had dramatically accelerated and an estimated 97 percent of the ice sheet surface had thawed by July 12. In the image, the areas classified as "probable melt" (light pink) correspond to those sites where at least one satellite detected surface melting. The areas classified as "melt" (dark pink) correspond to sites where two or three satellites detected surface melting.

Image credit: Jesse Allen, NASA Earth Observatory and Nicolo E. DiGirolamo, SSAI and Cryospheric Sciences Laboratory

Note: For more information, see Satellites see Unprecedented Greenland Ice Sheet Melt.

Wednesday, July 25, 2012

The Sun's Great Idea


The image was taken with SOHO’s LASCO 3 instrument (Large Angle and Spectrometric Coronagraph) on 27 February 2000. The shaded disc at the center of the image is a mask in the LASCO instrument that blots out direct sunlight to allow study of the faint details in the Sun's corona. The white circle added within the disc shows the size and position of the visible Sun.

SOHO is an international collaboration between ESA and NASA. It was launched in 1995 and orbits around the Sun in step with Earth, 1.5 million km away at the L1 point. Here, the combined gravity of Earth and Sun keep SOHO in an orbit locked to the Earth–Sun line, allowing SOHO to enjoy an uninterrupted view of our daylight star.

Photo credit: SOHO/LASCO (ESA & NASA)

Tuesday, July 24, 2012

Artist's Conception of Quasar 3C 279


This is an artist’s impression of the quasar 3C 279. Astronomers connected the Atacama Pathfinder Experiment (APEX), in Chile, to the Submillimeter Array (SMA) in Hawaii, USA, and the Submillimeter Telescope (SMT) in Arizona, USA for the first time, to make the sharpest observations ever, of the center of a distant galaxy, the bright quasar 3C 279. Quasars are the very bright centers of distant galaxies that are powered by supermassive black holes. This quasar contains a black hole with a mass about one billion times that of the Sun, and is so far from Earth that its light has taken more than 5 billion years to reach us. The team were able to probe scales of less than a light-year across the quasar — a remarkable achievement for a target that is billions of light-years away.

Illustration credit: ESO/M. Kornmesser

Note: For more information, see APEX Takes Part in Sharpest Observation Ever.

Monday, July 23, 2012

Possible Exoplanet UCF-1.01


Astronomers using NASA's Spitzer Space Telescope have detected what they believe is an alien world just two-thirds the size of Earth -- one of the smallest on record. The exoplanet candidate, known as UCF-1.01, orbits a star called GJ 436, which is located a mere 33 light-years away. UCF-1.01 might be the nearest world to our solar system that is smaller than our home planet.

Although probably rocky in composition like Earth, UCF-1.01 would be a terrible place for life. The world orbits scorchingly close to its star, so in all likelihood this planet lacks an atmosphere and might even have a molten surface, as shown in this artist's impression.

Evidence for UCF-1.01 turned up when astronomers were studying a known, Neptune-sized exoplanet, called GJ 436b, seen in the background in this image. The identification of nearby small planets may lead to their characterization using future instruments. In this way, worlds like UCF-1.01 might serve as stepping stones to one day finding a habitable, Earth-like exoplanet.

Because of GJ 436's proximity to our solar system, the star field around it shares many of our culture's famous cosmic landmarks. To the far left, the constellation of Orion gleams, though in a distorted shape compared to our vantage point on Earth. The red giant Betelgeuse (Orion's right shoulder) and blue Rigel (Orion's left foot) stand out, as well as the three belt stars. From GJ 436's perspective, however, the stars do not align as they do in our sky. The Pleiades star cluster is located to the upper left of UCF-1.01.

The artist's animation depicts a Star Trek-like voyage out to GJ 436, finished with a flyby of UCF-1.01.

Starting from Earth, we quickly zoom out of the solar system into our sun's local neighborhood, populated by the closest stars that lie within a few light-years of Earth. Swinging around, we shift our attention to the dwarf star GJ 436, which is so faint that it is invisible to us until we get close enough to see its dim glow.

From here we move into the GJ 436 system, at first seeing the candidate planet UCF-1.01 as it transits its star. Although probably rocky in composition like Earth, UCF-1.01 would be a terrible place for life. The world orbits scorchingly close to its star, so in all likelihood this planet lacks an atmosphere and might even have a molten surface, as shown in this animation.

Near the end of the movie, a Neptune-sized exoplanet already known to exist around GJ 436, designated GJ 436b, appears in the background. Evidence for UCF-1.01 turned up when astronomers were studying this previously known world.

Photo credit: NASA/JPL-Caltech

Note: For more information, see Spitzer Finds Possible Exoplanet Smaller Than Earth. To see the movie, click here.

Sunday, July 22, 2012

Lightning Strike on Saturn


These false-color mosaics from NASA's Cassini spacecraft capture lightning striking within the huge storm that encircled Saturn's northern hemisphere for much of 2011.

The larger mosaic on the left of the panel shows the lightning flash, which appears as a blue dot. The smaller mosaic on the right is composed of images taken 30 minutes later, and the lightning is not flashing at that time.

See PIA14904 for a mosaic showing a wider view wrapping around the planet also in which some blue lightning is visible in the clouds.

The white arrow in the annotated version of this panel points to the location where the lightning occurred in the clouds. The optical energy of this and other flashes on Saturn is comparable to the strongest of the flashes on Earth. The flash is approximately 120 miles (200 kilometers) in diameter when it exits the tops of the clouds. From this, scientists deduce that the lightning bolts originate in the clouds deeper down in Saturn's atmosphere where water droplets freeze. This is analogous to where lightning is created on Earth.

This lightning flash appears only in the filter sensitive to blue visible light, and the images were enhanced to increase the visibility of the lightning.

Images taken using red, green and blue spectral filters are usually combined to create a natural color view. Because visible red-light images were not available, images taken using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers were used in place of red. Also, the blue filter image was enhanced to increase the visibility of the lightning. The result is a type of false color image.

The images were obtained with the Cassini spacecraft narrow-angle camera on March 6, 2011, at a distance of approximately 2 million miles (3.3 million kilometers) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 83 degrees. These mosaics are simple cylindrical map projections, defined such that a square pixel subtends equal intervals of latitude and longitude. At higher latitudes, the pixel size in the north-south direction remains the same, but the pixel size (in terms of physical extent on the planet) in the east-west direction becomes smaller. The pixel size is set at the equator, where the distances along the sides are equal. This map has a pixel size of 12 miles (20 kilometers) at the equator.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Note: For more information, see Cassini Spots Daytime Lightning on Saturn.

Saturday, July 21, 2012

The "Pioneer Anomaly" Solved


The unexpected slowing of NASA's Pioneer 10 and 11 spacecraft - the so-called "Pioneer Anomaly" - turns out to be due to the slight, but detectable effect of heat pushing back on the spacecraft, according to a recent paper. The heat emanates from electrical current flowing through instruments and the thermoelectric power supply. The results were published on June 12 in the journal Physical Review Letters.

"The effect is something like when you're driving a car and the photons from your headlights are pushing you backward," said Slava Turyshev, the paper's lead author at NASA's Jet Propulsion Laboratory, Pasadena, California. "It is very subtle."

Launched in 1972 and 1973 respectively, Pioneer 10 and 11 are on an outward trajectory from our sun. In the early 1980s, navigators saw a deceleration on the two spacecraft, in the direction back toward the sun, as the spacecraft were approaching Saturn. They dismissed it as the effect of dribbles of leftover propellant still in the fuel lines after controllers had cut off the propellant. But by 1998, as the spacecraft kept traveling on their journey and were over 8 billion miles (13 billion kilometers) away from the sun, a group of scientists led by John Anderson of JPL realized there was an actual deceleration of about 300 inches per day squared (0.9 nanometers per second squared). They raised the possibility that this could be some new type of physics that contradicted Einstein's general theory of relativity.

In 2004, Turyshev decided to start gathering records stored all over the country and analyze the data to see if he could definitively figure out the source of the deceleration. In part, he and colleagues were contemplating a deep space physics mission to investigate the anomaly, and he wanted to be sure there was one before asking NASA for a spacecraft.

He and colleagues went searching for Doppler data, the pattern of data communicated back to Earth from the spacecraft, and telemetry data, the housekeeping data sent back from the spacecraft. At the time these two Pioneers were launched, data were still being stored on punch cards. But Turyshev and colleagues were able to copy digitized files from the computer of JPL navigators who have helped steer the Pioneer spacecraft since the 1970s. They also found over a dozen of boxes of magnetic tapes stored under a staircase at JPL and received files from the National Space Science Data Center at NASA Goddard Space Flight Center, Greenbelt, Maryland, and worked with NASA Ames Research Center, Moffett Field, California, to save some of their boxes of magnetic optical tapes. He collected more than 43 gigabytes of data, which may not seem like a lot now, but is quite a lot of data for the 1970s. He also managed to save a vintage tape machine that was about to be discarded, so he could play the magnetic tapes.

The effort was a labor of love for Turyshev and others. The Planetary Society sent out appeals to its members to help fund the data recovery effort. NASA later also provided funding. In the process, a programmer in Canada, Viktor Toth, heard about the effort and contacted Turyshev. He helped Turyshev create a program that could read the telemetry tapes and clean up the old data.

They saw that what was happening to Pioneer wasn't happening to other spacecraft, mostly because of the way the spacecraft were built. For example, the Voyager spacecraft are less sensitive to the effect seen on Pioneer, because its thrusters align it along three axes, whereas the Pioneer spacecraft rely on spinning to stay stable.

With all the data newly available, Turyshev and colleagues were able to calculate the heat put out by the electrical subsystems and the decay of plutonium in the Pioneer power sources, which matched the anomalous acceleration seen on both Pioneers.

"The story is finding its conclusion because it turns out that standard physics prevail," Turyshev said. "While of course it would've been exciting to discover a new kind of physics, we did solve a mystery."

Pioneer 10 and 11 were managed by NASA Ames Research Center, Moffett Field, Calif. Pioneer 10's last signal was received on Earth in January 2003. Pioneer 11's last signal was received in November 1995.

Illustration credit: NASA

Friday, July 20, 2012

Titan's South Polar Vortex


This true color image captured by NASA'S Cassini spacecraft before a distant flyby of Saturn's moon Titan on June 27, 2012, shows a south polar vortex, or a swirling mass of gas around the pole in the atmosphere.

The south pole of Titan (3,200 miles, or 5,150 kilometers, across) is near the center of the view.

Since Cassini arrived in the Saturn system in 2004, Titan has had a visible "hood" high above the north pole (see PIA08137). It was northern winter at Cassini's arrival, and much of the high northern latitudes were in darkness. But the hood, an area of denser, high altitude haze compared to the rest of the moon's atmosphere, was high enough to be still illuminated by sunlight. The seasons have been changing since Saturn's August 2009 equinox signaled the beginning of spring in the northern hemisphere and fall in the southern hemisphere for the planet and its many moons. Now the high southern latitudes are moving into darkness. The formation of the vortex at Titan's south pole may be related to the coming southern winter and the start of what will be a south polar hood.

See PIA14920 for a movie captured with a similar view and showing the polar vortex in motion.

These new, more detailed images are only possible because of Cassini's newly inclined orbits, which are the next phase of Cassini Solstice Mission. Previously, Cassini was orbiting in the equatorial plane of the planet, and the imaging team's images of the polar vortex between late March and mid-May were taken from over Titan's equator. At that time, images showed a brightening or yellowing of the detached haze layer on the limb, or edge of the visible disk of the moon, over the south polar region.

Scientists think these new images show open cell convection. In open cells, air sinks in the center of the cell and rises at the edge, forming clouds at cell edges. However, because the scientists can't see the layer underneath the layer visible in these new images, they don't know what mechanisms may be at work.

Cosmic ray hits on the camera detectors appear as bright dots in the black and white version of the image (Figure 1).

Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained with the Cassini spacecraft narrow-angle camera late on June 26, 2012 at a distance of approximately 301,000 miles (484,000 kilometers) from Titan. Image scale is 2 miles (3 kilometers) per pixel.



Photo credit: NASA/JPL-Caltech/Space Science Institute; video credit: NASA/JPL-Caltech/Space Science Institute

Note: For more information, see The Titanian Seasons Turn, Turn, Turn; also, PIA14920: Titan's South Polar Vortex in Motion.

Thursday, July 19, 2012

Searching for Exoplanets Around HD 157728


These two images show HD 157728, a nearby star 1.5 times larger than the sun. The star is centered in both images, and its light has been mostly removed by an adaptive optics system and coronagraph belonging to Project 1640, which uses new technology on the Palomar Observatory's 200-inch Hale telescope near San Diego, California, to spot planets. The remaining starlight leaves a speckled background against which fainter objects cannot be seen. On the left, the image was made without the ultra-precise starlight control that Project 1640 is capable of. On the right, the wavefront sensor was active, and a darker square hole formed in the residual starlight, which will allow objects up to 10 million times fainter than the star to be seen. Images were taken on June 14, 2012. Researchers and engineers behind the project come from the American Museum of Natural History in New York, N.Y., the California Institute of Technology in Pasadena, and NASA's Jet Propulsion Laboratory, also in Pasadena.

Photo credit: Project 1640

Note: For more information, see New Instrument Sifts Starlight for New Worlds

Wednesday, July 18, 2012

Greeley Haven Panorama


This full-circle scene combines 817 images taken by the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity. It shows the terrain that surrounded the rover while it was stationary for four months of work during its most recent Martian winter.

Opportunity's Pancam took the component images between the 2,811th Martian day, or sol, of the rover's Mars surface mission (December 21, 2011) and Sol 2,947 (May 8, 2012). Opportunity spent those months on a northward sloped outcrop, "Greeley Haven," which angled the rover's solar panels toward the sun low in the northern sky during southern hemisphere winter. The outcrop's informal name is a tribute to Ronald Greeley (1939-2011), who was a member of the mission team and who taught generations of planetary scientists at Arizona State University, Tempe. The site is near the northern tip of the "Cape York" segment of the western rim of Endeavour Crater.

North is at the center of the image. South is at both ends. On the far left at the horizon is "Rich Morris Hill." That outcrop on Cape York was informally named in memory of John R. "Rich" Morris (1973-2011), an aerospace engineer and musician who was a Mars rover team member and mission manager at NASA's Jet Propulsion Laboratory, Pasadena.

Bright wind-blown deposits on the left are banked up against the Greeley Haven outcrop. Opportunity's tracks can be seen extending from the south, with a turn-in-place and other maneuvers evident from activities to position the rover at Greeley Haven. The tracks in some locations have exposed darker underlying soils by disturbing a thin, bright dust cover.

Other bright, dusty deposits can be seen to the north, northeast, and east of Greeley Haven. The deposit at the center of the image, due north from the rover's winter location, is a dusty patch called "North Pole." Opportunity drove to it and investigated it in May 2012 as an example of wind-blown Martian dust.

The interior of Endeavour Crater can been seen just below the horizon in the right half of the scene, to the northeast and east of Cape York. The crater spans 14 miles (22 kilometers) in diameter.

Opportunity's solar panels and other structures show dust that has accumulated over the lifetime of the mission. Opportunity has been working on Mars since January 2004.

During the recent four months that Opportunity worked at Greeley Haven, activities included radio-science observations to better understand Martian spin axis dynamics and thus interior structure, investigations of the composition and textures of an outcrop exposing an impact-jumbled rock formation on the crater rim, monitoring the atmosphere and surface for changes, and acquisition of this full-color mosaic of the surroundings.

The panorama combines exposures taken through Pancam filters centered on wavelengths of 753 nanometers (near infrared), 535 nanometers (green) and 432 nanometers (violet). The view is presented in false color to make some differences between materials easier to see.

Photo credit: NASA/JPL-Caltech/Cornell/Arizona State University

Note: For more information, see Mars Panorama: Next Best Thing to Being There.

Tuesday, July 17, 2012

TYC 8241 2652: The Mysterious Case of the Disappearing Dust


Imagine if the rings of Saturn suddenly disappeared. Astronomers have witnessed the equivalent around a young sun-like star called TYC 8241 2652. Enormous amounts of dust known to circle the star are unexpectedly nowhere to be found.

"It's like the classic magician's trick: now you see it, now you don't. Only in this case we're talking about enough dust to fill an inner solar system and it really is gone!" said Carl Melis of the University of California, San Diego, who led the new study appearing in the July 5 issue of the journal Nature.

A dusty disk around TYC 8241 2652 was first seen by the NASA Infrared
Astronomical Satellite (IRAS) in 1983, and continued to glow brightly for 25 years. The dust was thought to be due to collisions between forming planets, a normal part of planet formation. Like Earth, warm dust absorbs the energy of visible starlight and reradiates that energy as infrared, or heat, radiation.

The first strong indication of the disk's disappearance came from images taken in January 2010 by NASA's Wide-field Infrared Survey Explorer, or WISE. An infrared image obtained at the Gemini telescope in Chile on May 1, 2012, confirmed that the dust has now been gone for two-and-a-half years.

"Nothing like this has ever been seen in the many hundreds of stars that astronomers have studied for dust rings," said co-author Ben Zuckerman of UCLA, whose research is funded by NASA. "This disappearance is remarkably fast even on a human time scale, much less an astronomical scale. The dust disappearance at TYC 8241 2652 was so bizarre and so quick, initially I figured that our observations must simply be wrong in some strange way."

The astronomers have come up with a couple of possible solutions to the mystery, but they say none are compelling. One possibility is that gas produced in the impact that released the dust helped to quickly drag the dust particles into the star and thus to their doom. In another possibility, collisions of large rocks left over from an original major impact provide a fresh infusion of dust particles into the disk, which caused the dust grains to chip apart into smaller and smaller pieces.

The result is based upon multiple sets of observations of TYC 8241 2652 obtained with the Thermal-Region Camera Spectrograph on the Gemini South telescope in Chile; IRAS; WISE; NASA's Infrared Telescope on Mauna Kea in Hawaii; the European Space Agency's Herschel Space Telescope, in which NASA plays an important role; and the Japanese/European Space Agency AKARI infrared satellite.

Illustration credit: NASA/JPL-Caltech

Monday, July 16, 2012

Dark Galaxies Spotted for the First Time


This deep image shows the region of the sky around the quasar HE0109-3518. The quasar is labeled with a red circle near the center of the image. The energetic radiation of the quasar makes dark galaxies glow, helping astronomers to understand the obscure early stages of galaxy formation. The faint images of the glow from 12 dark galaxies are labeled with blue circles. Dark galaxies are essentially devoid of stars, therefore they don’t emit any light that telescopes can catch. This makes them virtually impossible to observe unless they are illuminated by an external light source like a background quasar.

This image combines observations from the Very Large Telescope, tuned to detect the fluorescent emissions produced by the quasar illuminating the dark galaxies, with color data from the Digitized Sky Survey 2.

Photo credit: ESO, Digitized Sky Survey 2 and S. Cantalupo (UCSC)

Note: For more information, see Dark Galaxies of the Early Universe Spotted for the First Time. An unannotated version of this image may be found here.

Sunday, July 15, 2012

V1647 Ori - X-Raying the Beating Heart of a Newborn Star



An artist's impression of what might be happening behind the thick dust disc surrounding the young Sun-like star V1647 Ori.

X-ray observations by ESA's XMM-Newton, NASA's Chandra and Japan's Suzaku space observatories have probed the interior of the dust disc to find a rapidly-rotating star spinning with a period of one day. At 80 per cent the mass of our Sun and with a diameter approximately four times larger, spinning at this rate nears break-up speed for a star of this size.

The data also suggest that matter is accreting onto the stellar surface in two pancake-shaped hotspots located on opposite sides of the star, in which the matter heats up and the high temperature plasma is confined.

Video credit: ESA/C. Carreau; text credit: ESA

Note: For more information, see X-Raying the Beating Heart of a Newborn Star; also, V1647 Ori: X-Raying the Beating Heart of a Newborn Star .

Saturday, July 14, 2012

A Swarm of Dark Matter Around the Milky Way


These illustrations, taken from computer simulations, show a swarm of dark matter clumps around our Milky Way galaxy. Some of the dark-matter concentrations are massive enough to spark star formation. Dark matter is an invisible substance that accounts for most of the universe's mass.

In the first panel, thousands of clumps of dark matter coexist with our Milky Way galaxy, shown in the center.

The green blobs in the second panel are those dark-matter chunks massive enough to obtain gas from the intergalactic medium and trigger ongoing star formation, eventually creating dwarf galaxies.

In the third panel, the red blobs are ultra-faint dwarf galaxies that stopped forming stars long ago. New Hubble Space Telescope observations of three of the puny galaxies reveal that star-making in these faint galaxies shut down more than 13 billion years ago.

The synchronized shutdown is evidence that a global event, such as reionization, swept through the early universe. Reionization is a transitional phase in the early universe when the first stars burned off a fog of cold hydrogen.

Popular theory predicts that most of the Milky Way's satellites contain few, if any, stars and are instead dominated by dark matter. More than a dozen small-fry galaxies have been found so far, all by the Sloan Digital Sky Survey, which scanned just a quarter of the sky.

Illustration credit: J. Tumlinson (STScI)

Note: For more information, see Hubble Unmasks Ghost Galaxies.

Friday, July 13, 2012

Pluto and Its Five Moons


This image, taken by the NASA/ESA Hubble Space Telescope, shows five moons orbiting the distant, icy dwarf planet Pluto.

The green circle marks the newly discovered moon, designated S/2012 (134340) 1, or P5, as photographed by Hubble's Wide Field Camera 3 on 7 July 2012.

Other observations that collectively show the moon's orbital motion were taken on 26, 27 and 29 June and on July 9.

The moon is estimated to be 10 to 25 kilometers across. It is in a 95,000 kilometer diameter circular orbit around Pluto that is assumed to be aligned in the same plane as the other satellites in the system.

The darker stripe in the center of the image is because the picture is constructed from a long exposure designed to capture the comparatively faint satellites of Nix, Hydra, P4 and S/2012 (134340) 1, and a shorter exposure to capture Pluto and Charon, which are much brighter.

Photo credit: NASA, ESA, and M. Showalter (SETI Institute)

Note: For more information, see Hubble Discovers New Pluto Moon; also, Fifth Moon Discovered Around Pluto. And ScienceCasts reminds us that the New Horizons spacecraft will be flying past Pluto in 2015. (This video is a little dated already in that the narrator announces the then-recent discovery of a fourth moon.

Thursday, July 12, 2012

Vela-C Molecular Cloud in Optical and Far-Infrared


This image shows the Vela-C molecular cloud region as observed at optical (upper panel) and far-infrared (lower panel) wavelengths.

The optical image is dominated by the emission from stars. The eerie orange cloud in the center-left part of the image is known as RCW 36 (or Gum 20); it is an HII region – a pocket of gas that is being energized and ionized by the action of nearby young, massive stars. Another HII region, called RCW 34 (or Gum 19), can be seen as a small orange fleck in the lower part of the image to the right.

In the far-infrared image, obtained using ESA's Herschel Space Observatory, the reservoir of gas and dust that pervades the Vela-C region is revealed in its full glory. Cosmic dust is a minor but crucial component of the interstellar medium and, due to its low temperature, it shines brightly at the far-infrared wavelengths that Herschel is designed to observe. The image shows how the raw material from which stars form is organized in tangled nests as well as dense, ridge-like filaments. The white flecks that dot the clouds and filaments are the seeds of future stellar generations.

The two HII regions RCW 36 and RCW 34 stand out also in the far-infrared image. Due to their higher temperature relative to the colder material in the cloud, they shine brightly at the shortest wavelengths probed by Herschel, indicated in blue in the image.

The Vela-C molecular cloud is the most massive component of the Vela Molecular Ridge, a vast and prolific star-forming complex in the plane of our Galaxy, the Milky Way.

Photo credits: ESO/Digitized Sky Survey 2 (upper panel); ESA/PACS/SPIRE/Tracey Hill & Frédérique Motte, Laboratoire AIM Paris-Saclay, CEA/Irfu - CNRS/INSU - Univ. Paris Diderot, France (lower panel)

Note: For more information, see Tangled Nests and Filaments: Stellar Nurseries in Vela-C.

Wednesday, July 11, 2012

IGR J11014-6103 - The Fastest Moving Pulsar?


IGR J11014-6103: A pulsar found racing away from a supernova remnant about 30,000 light years from Earth.

Using Chandra, XMM-Newton, and the Parkes radio telescope, researchers have found evidence for what may be the fastest moving pulsar ever seen. The large field of view contains XMM-Newton X-ray data (purple) that shows a supernova remnant, combined with infrared and optical data (colored red, green and blue that appears as white) showing stars. The Chandra image in bright green shown in the inset ("Chandra Close-up") reveals a comet-shaped X-ray source well outside the boundary of the supernova remnant. Astronomers think that this object is a pulsar that may be moving at about 6 million miles per hour, which would make it one of the fastest ever detected if confirmed.

Photo credit: X-ray: NASA/CXC/UC Berkeley/J.Tomsick et al & ESA/XMM-Newton, Optical: DSS; IR: 2MASS/UMass/IPAC-Caltech/NASA/NSF

Note: For more information, see IGR J11014-6103: Has the Speediest Pulsar Been Found?

Tuesday, July 10, 2012

Melas Dorsa


High-Resolution Stereo Camera (HRSC) nadir and color channel data taken during revolution 10532 on 17 April 2012 by ESA’s Mars Express have been combined to form a natural-color view of the Melas Dorsa region. Centered at around 18°S and 288°E, this image has a ground resolution of about 18 m per pixel. The image shows the wrinkle ridges bisected by crustal displacement faults known as ‘en-echelon’ faults along with the large impact crater with its butterfly-shaped fluidized ejecta blanket. En-echelon faults are closely spaced, parallel overlapping or step-like fault structures, which in this view can be seen at the far left of the image, intersecting the wrinkle ridges.

Photo credit: ESA/DLR/FU Berlin (G. Neukum)

Monday, July 9, 2012

Entrainement


ESA astronaut Samantha Cristoforetti training for spacewalks in NASA’s Neutral Buoyancy Laboratory in Houston, USA. Diving underwater is as close as it gets to experiencing weightlessness on Earth for long periods of time. To simulate floating in space, astronauts don the suits before being lowered into a large diving pool. Should future missions require Samantha to venture outside the International Space Station to install new equipment or collect samples, she needs to know how to use spacesuits.

Photo credit: NASA/ESA

Sunday, July 8, 2012

The Flame Nebula in Infrared


The Flame Nebula sits on the eastern hip of Orion the Hunter, a constellation most easily visible in the northern hemisphere during winter evenings. This view of the Flame nebula from WISE, NASA's Wide-field Infrared Survey Explorer, shows an expanded view over one previously released of this enormous space cloud (PIA13448).

The previous image was made from data WISE collected after its coolant began to run out, when only three of WISE's infrared bands were in operation. The Flame Nebula is a very infrared-bright region, and the reduced sensitivity during the 3-band phase of the WISE mission worked to the advantage of astronomers interested in studying the brightest parts of this region without so much glare. This new image includes more data collected from all of WISE's four infrared bands. This view takes in a vast cloud of gas and dust where new stars are being born. Three familiar nebulae are visible in the central region: the Flame nebula, the Horsehead nebula, and NGC 2023. The Flame is the brightest and largest in the image. It is being lit up by a star inside it that is 20 times the mass of the sun and would be as bright to our eyes as the other stars in Orion's belt if it weren't for all the surrounding dust, which makes it appear 4 billion times dimmer than it really is.

NGC 2023 is the bright knot below the Flame. The famous Horsehead nebula is visible poking out of the edge of the cloud, just to the right of NGC 2023 and down a touch. It takes on a very different view in infrared compared to visible light. In visible light, the horse's head is a silhouetted dark cloud in front of glowing gas. But here, we see the dust in that dark cloud glowing in infrared light.

Two of the three stars in Orion's belt are visible in this image, but despite their prominence to our eyes in the night sky, they are somewhat unremarkable as seen by WISE. Alnitak, the far left star in Orion's belt, is a multiple blue-giant star system located 736 light-years away. In this image, it is located just to the right of the central part of the Flame nebula. Alnilam, the middle star of Orion's belt, is a variable blue supergiant, located 1,980 light-years away. Despite having a radius 24 times bigger than the sun, and luminosity 275,000 times greater than the sun, it only appears as a moderately bright star near the upper right corner of this image.

Another noteworthy feature in this image is the bright red arc at the lower right. This arc surrounds the star Sigma Orionis, the upper star in the sword of Orion, which hangs from his belt. It is a blue dwarf multiple star system, located 1,070 light-years away. It is moving through space at a breathtaking speed of 5,260,000 mph (2,400 kilometers per second). At that speed, winds from the star system crash into the gas and dust outside the system and create a bow shock, where material in front of the speeding Sigma Orionis system is piling up. The energy from the bow shock heats up dust in the region and makes it glow in infrared.

Color in this image represents specific infrared wavelengths. Blue represents light emitted at 3.4-micron wavelengths, and cyan (blue-green) represents 4.6-microns, both of which come mainly from hot stars. Relatively cooler objects, such as the dust of the nebulae, appear green and red. Green represents 12-micron light and red represents 22-micron light.

Photo credit: NASA/JPL-Caltech/UCLA

Saturday, July 7, 2012

U Camelopardalis


Camelopardalis, or U Cam for short, is a star nearing the end of its life. As stars run low on fuel, they become unstable. Every few thousand years, U Cam coughs out a nearly spherical shell of gas as a layer of helium around its core begins to fuse. The gas ejected in the star’s latest eruption is clearly visible in this picture as a faint bubble of gas surrounding the star.

U Cam is an example of a carbon star, a rare type of star with an atmosphere that contains more carbon than oxygen. Due to its low surface gravity, typically as much as half of the total mass of a carbon star may be lost by way of powerful stellar winds. Located in the constellation of Camelopardalis (The Giraffe), near the North Celestial Pole, U Cam itself is much smaller than it appears in this Hubble image. In fact, the star would easily fit within a single pixel at the center of the image. Its brightness, however, is enough to saturate the camera's receptors, making the star look much larger than it is.

The shell of gas, which is both much larger and much fainter than its parent star, is visible in intricate detail in Hubble’s portrait. This phenomenon is often quite irregular and unstable, but the shell of gas expelled from U Cam is almost perfectly spherical.

Photo credit: ESA/NASA

Friday, July 6, 2012

M5.3 Solar Flare


This image, captured by the Solar Dynamics Observatory, shows the M5.3 class solar flare that peaked on July 4, 2012, at 5:55 AM EDT. The flare is shown in the 131 Angstrom wavelength, a wavelength that is particularly good for capturing the radiation emitted from flares. The wavelength is typically colorized in teal as shown here.

Photo credit: NASA/SDO/AIA/Helioviewer

Thursday, July 5, 2012

DDO 82 Dwarf Galaxy


Relatively few galaxies possess the sweeping, luminous spiral arms or brightly glowing center of our home galaxy the Milky Way. In fact, most galaxies look like small, amorphous clouds of vapor. One of these galaxies is DDO 82, captured by the Hubble Space Telescope. Though tiny compared to the Milky Way, such dwarf galaxies may contain between a few million and a few billion stars.

DDO 82, also known by the designation UGC 5692, is not without a hint of structure, however. Astronomers classify it as an "Sm galaxy," or Magellanic spiral galaxy, named after the Large Magellanic Cloud, a dwarf galaxy that orbits the Milky Way. That galaxy, like DDO 82, is said to have one spiral arm.

DDO 82 can be found in the constellation of Ursa Major (the Great Bear) approximately 13 million light-years away. The object is considered part of the M81 Group of around three dozen galaxies. DDO 82 gets its name from its entry number in the David Dunlap Observatory Catalogue. Canadian astronomer Sidney van den Bergh originally compiled this list of dwarf galaxies in 1959.

The image is made up of exposures taken in visible and infrared light by Hubble’s Advanced Camera for Surveys.

Photo credit: ESA/NASA

Wednesday, July 4, 2012

Herbig-Haro 110


The NASA/ESA Hubble Space Telescope has captured a new image of Herbig-Haro 110, a geyser of hot gas flowing from a newborn star. HH 110 appears different from most other Herbig-Haro objects: in particular, it appears on its own while they usually come in pairs. Astronomers think it may be a continuation of another object called HH 270, after it has been deflected off a dense cloud of gas.

Photo credit: NASA, ESA and the Hubble Heritage team (STScI/AURA)

Note: For more information, see A Geyser of Hot Gas Flowing From a Star.

Tuesday, July 3, 2012

Soyuz Landing


The Soyuz TMA-03M capsule with astronauts Don Pettit, Oleg Kononenko and ESA astronaut André Kuipers touchdown on Sunday 1 July 2012 at 08:14 GMT.

They landed in the steppes of Kazakhstan after 193 days in space. During André's six-month PromISSe mission on the International Space Station, he conducted many scientific experiments in the world’s only permanent microgravity laboratory.

In addition to his scientific workload, André carried out maintenance and operational tasks. Highlights included receiving ESA’s Automated Transfer Vehicle Edoardo Amaldi cargo ferry and docking the first commercial spacecraft, Dragon.

Photo credit: ESA–S. Corvaja, 2012

Monday, July 2, 2012

Tau Boötis b


This artist’s impression shows the exoplanet Tau Boötis b. This was one of the first exoplanets to be discovered back in 1996, and it is still one of the closest planetary systems known to date. Astronomers using ESO’s Very Large Telescope have now caught and studied the faint light from the planet Tau Boötis b for the first time. By employing a clever observational trick the team find that the planet’s atmosphere seems to be cooler higher up, the opposite of what was expected.

Illustration credit: ESO/L. Calçada

Note: For more information, see New Way of Probing Exoplanet Atmospheres.

Sunday, July 1, 2012

Cygnus X-1 by NuSTAR


NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, has taken its first snapshots of the highest energy X-rays in the cosmos, the same kind used by doctors to take pictures of your bones. NuSTAR chose a black hole in the constellation Cygnus (shown on the left) as its first target due to its brightness.

The inset image on the top right was taken with the INTEGRAL high-energy telescope; the image is 1 degree across, or twice the diameter of the moon. The bottom image shows NuSTAR's snapshot of the central part of that image. While INTEGRAL studies sources over wide swaths of sky, NuSTAR zooms into selected regions with much crisper vision.

Cygnus X-1 is a black hole that is siphoning matter from a giant companion star and spitting out high-energy X-rays. It is located in our Milky Way galaxy, about 6,000 light-years from Earth.

The NuSTAR team will use this and other "first-light" images to calibrate the pointing alignment between the spacecraft and the X-ray telescope.

Image credit: NASA/JPL-Caltech

Note: For more information, see Space Telescope Opens Its X-Ray Eyes.