Rosetta takes a selfie with its target comet in the background. This photo was taken last year as the spacecraft orbited the comet. The European Space Agency's Rosetta spacecraft came close enough to almost kiss a comet on Valentine's Day this year.
On February 14, the spacecraft came to within 3.7 miles of the comet's surface â 10 times closer than when Rosetta closed in on its target last year to deploy the Philae probe, which is the first probe to ever soft land on a comet making history when it did on November 12.
This time around Rosetta's NAVCAM instrument took over a dozen close-up shots of the comet's arresting surface features â and they are some of the best photos we've ever seen.
Rosetta began prepping for closest approach on February 4 when it fired its thrusters to break course from its current flight path. This is what Rosetta saw a couple of days later, on February 6, from 77 miles away:
But the most incredible photos of all are the ones the spacecraft captured from a mere 3.7 miles above the surface:
Click here for more close-up photos and info.
Hubble Images a Dusty Galaxy, Home to an Exploding Star
The galaxy pictured here is NGC 4424, located in the constellation of Virgo. It is not visible with the naked eye but has been captured here with the NASA/ESA Hubble Space Telescope.
Although it may not be obvious from this image, NGC 4424 is in fact a spiral galaxy. In this image it is seen more or less edge on, but from above, you would be able to see the arms of the galaxy wrapping around its center to give the characteristic spiral form.
In 2012, astronomers observed a supernova in NGC 4424 — a violent explosion marking the end of a star’s life. During a supernova explosion, a single star can often outshine an entire galaxy. However, the supernova in NGC 4424, dubbed SN 2012cg, cannot be seen here as the image was taken ten years prior to the explosion. Along the central region of the galaxy, clouds of dust block the light from distant stars and create dark patches.
To the left of NGC 4424 there are two bright objects in the frame. The brightest is another, smaller galaxy known as LEDA 213994 and the object closer to NGC 4424 is an anonymous star in our Milky Way.
European Space Agency
Credit: ESA/Hubble & NASA, Acknowledgement: Gilles Chapdelaine
Hubble's Little Sombrero
Galaxies can take many shapes and be oriented any way relative to us in the sky. This can make it hard to figure out their actual morphology, as a galaxy can look very different from different viewpoints. A special case is when we are lucky enough to observe a spiral galaxy directly from its edge, providing us with a spectacular view like the one seen in this picture of the week.
This is NGC 7814, also known as the “Little Sombrero.” Its larger namesake, the Sombrero Galaxy, is another stunning example of an edge-on galaxy — in fact, the “Little Sombrero” is about the same size as its bright namesake at about 60,000 light-years across, but as it lies farther away, and so appears smaller in the sky.
NGC 7814 has a bright central bulge and a bright halo of glowing gas extending outwards into space. The dusty spiral arms appear as dark streaks. They consist of dusty material that absorbs and blocks light from the galactic center behind it. The field of view of this NASA/ESA Hubble Space Telescope image would be very impressive even without NGC 7814 in front; nearly all the objects seen in this image are galaxies as well.
European Space Agency Credit: ESA/Hubble & NASA
Acknowledgement: Josh Barrington
Hubble’s High-Definition Panoramic View of the Andromeda Galaxy
The largest NASA Hubble Space Telescope image ever assembled, this sweeping bird’s-eye view of a portion of the Andromeda galaxy (M31) is the sharpest large composite image ever taken of our galactic next-door neighbor. Though the galaxy is over 2 million light-years away, the Hubble Space Telescope is powerful enough to resolve individual stars in a 61,000-light-year-long stretch of the galaxy’s pancake-shaped disk. It's like photographing a beach and resolving individual grains of sand. And there are lots of stars in this sweeping view -- over 100 million, with some of them in thousands of star clusters seen embedded in the disk.
This ambitious photographic cartography of the Andromeda galaxy represents a new benchmark for precision studies of large spiral galaxies that dominate the universe's population of over 100 billion galaxies. Never before have astronomers been able to see individual stars inside an external spiral galaxy over such a large contiguous area. Most of the stars in the universe live inside such majestic star cities, and this is the first data that reveal populations of stars in context to their home galaxy.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.
Image Credit: NASA, ESA, J. Dalcanton, B.F. Williams, and L.C. Johnson (U. of Washington), the Panchromatic Hubble Andromeda Treasury (PHAT) team, and R. Gendler
Taking a Closer Look at Orion After Successful Flight Test
Engineers across the country have been busy taking a closer look at NASA's Orion spacecraft and the data it produced during its successful flight test in December 2014. Inside the Launch Abort System Facility at NASA's Kennedy Space Center in Florida, Orion was lifted using a special crane for removal of its heat shield on Feb. 13, 2015. In the background, technicians move the heat shield on a work stand. The spacecraft’s heat shield protected Orion as it reentered Earth’s atmosphere at searing temperatures. Removing the back shell allows the team to get a closer look at Orion’s systems to see how they fared during the trip to space. The heat shield was removed in preparation for shipment to NASA’s Marshall Space Flight Center in Huntsville, Alabama, where special equipment will be used to remove its ablative material. From there, the heat shield will be shipped to NASA’s Langley Research Center in Hampton, Virginia, where it will be outfitted on a test article for water impact testing.
Meanwhile, NASA and Lockheed Martin, the prime contractor for Orion, continue to take a look at the data the flight test produced to validate pre-flight models and improve the spacecraft’s design. Analysis of data obtained during its two-orbit, four-and-a-half hour mission Dec. 5 will provide engineers detailed information on how the spacecraft fared.
Photo Credit: NASA/Jim Grossmann
Astronauts Complete Series of Three Spacewalks
On Sunday, March 1, Expedition 42 Flight Engineer Terry Virts and Commander Barry "Butch" Wilmore ventured outside the International Space Station for their third spacewalk in eight days. Virts and Wilmore completed installing 400 feet of cable and several antennas associated with the Common Communications for Visiting Vehicles system known as C2V2. Boeing’s Crew Transportation System (CST)-100 and the SpaceX Crew Dragon will use the system in the coming years to rendezvous with the orbital laboratory and deliver crews to the space station.
Virts (@AstroTerry) tweeted this photograph and wrote, "Out on the P3 truss. #AstroButch handing me his cable to install on the new antenna. #spacewalk"
Image Credit: NASA
"Mini Supernova" Explosion Could Have Big Impact
In Hollywood blockbusters, explosions are often among the stars of the show. In space, explosions of actual stars are a focus for scientists who hope to better understand their births, lives, and deaths and how they interact with their surroundings.
Using NASA’s Chandra X-ray Observatory, astronomers have studied one particular explosion that may provide clues to the dynamics of other, much larger stellar eruptions.
A team of researchers pointed the telescope at GK Persei, an object that became a sensation in the astronomical world in 1901 when it suddenly appeared as one of the brightest stars in the sky for a few days, before gradually fading away in brightness. Today, astronomers cite GK Persei as an example of a “classical nova,” an outburst produced by a thermonuclear explosion on the surface of a white dwarf star, the dense remnant of a Sun-like star.
A nova can occur if the strong gravity of a white dwarf pulls material from its orbiting companion star. If enough material, mostly in the form of hydrogen gas, accumulates on the surface of the white dwarf, nuclear fusion reactions can occur and intensify, culminating into a cosmic-sized hydrogen bomb blast. The outer layers of the white dwarf are blown away, producing a nova outburst that can be observed for a period of months to years as the material expands into space.
Classical novas can be considered to be “miniature” versions of supernova explosions. Supernovas signal the destruction of an entire star and can be so bright that they outshine the whole galaxy where they are found. Supernovas are extremely important for cosmic ecology because they inject huge amounts of energy into the interstellar gas, and are responsible for dispersing elements such as iron, calcium and oxygen into space where they may be incorporated into future generations of stars and planets.
Although the remnants of supernovas are much more massive and energetic than classical novas, some of the fundamental physics is the same. Both involve an explosion and creation of a shock wave that travels at supersonic speeds through the surrounding gas.
The more modest energies and masses associated with classical novas means that the remnants evolve more quickly. This, plus the much higher frequency of their occurrence compared to supenovas, makes classical novas important targets for studying cosmic explosions.
Chandra first observed GK Persei in February 2000 and then again in November 2013. This 13-year baseline provides astronomers with enough time to notice important differences in the X-ray emission and its properties.
This new image of GK Persei contains X-rays from Chandra (blue), optical data from NASA’s Hubble Space Telescope (yellow), and radio data from the National Science Foundation’s Very Large Array (pink). The X-ray data show hot gas and the radio data show emission from electrons that have been accelerated to high energies by the nova shock wave. The optical data reveal clumps of material that were ejected in the explosion. The nature of the point-like source on the lower left is unknown.
Over the years that the Chandra data span, the nova debris expanded at a speed of about 700,000 miles per hour. This translates to the blast wave moving about 90 billion miles during that period.
One intriguing discovery illustrates how the study of nova remnants can provide important clues about the environment of the explosion. The X-ray luminosity of the GK Persei remnant decreased by about 40% over the 13 years between the Chandra observations, whereas the temperature of the gas in the remnant has essentially remained constant, at about one million degrees Celsius. As the shock wave expanded and heated an increasing amount of matter, the temperature behind the wave of energy should have decreased. The observed fading and constant temperature suggests that the wave of energy has swept up a negligible amount of gas in the environment around the star over the past 13 years. This suggests that the wave must currently be expanding into a region of much lower density than before, giving clues to stellar neighborhood in which GK Persei resides.
A paper describing these results appeared in the March 10th issue of The Astrophysical Journal. The authors were Dai Takei (RIKEN, Spring-8 Center Japan), Jeremy Drake (Smithsonian Astrophysical Observatory), Hiroya Yamaguichi (Goddard Space Flight Center), Patrick Slane (Smithsonian Astrophysical Observatory), Yasunobu Uchimaya (Rikkyo University, Japan), Satoru Katsuda (Japanese Aerospace Exploration Agency).
NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.
› Read More from NASA’s Chandra X-ray Observatory
Image Credit: NASA/CXC/RIKEN/D.Takei et al
Marshall Space Flight Center, Huntsville, Ala.
Chandra X-ray Center, Cambridge, Mass.
Mars 'Marathon Valley' Overlook
This view from NASA's Mars Exploration Rover Opportunity shows part of "Marathon Valley," a destination on the western rim of Endeavour Crater, as seen from an overlook north of the valley.
The scene spans from east, at left, to southeast. It combines four pointings of the rover's panoramic camera (Pancam) on March 13, 2015, during the 3,958th Martian day, or sol, of Opportunity's work on Mars.
The rover team selected Marathon Valley as a science destination because observations of this location using the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument on NASA's Mars Reconnaissance Orbiter yielded evidence of clay minerals, a clue to ancient wet environments. By the time Opportunity explores Marathon Valley, the rover will have exceeded a total driving distance equivalent to an Olympic marathon. Opportunity has been exploring the Meridiani Planum region of Mars since January 2004.
This version of the image is presented in approximate true color by combining exposures taken through three of the Pancam's color filters at each of the four camera pointings, using filters centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet).
Image Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
Mountaineer Buc wrote:Pakistani photographer Atif Saeed captured this incredible image of a lion at a wildlife park outside of Lahore by slowly creeping out of his car's open door. The 38-year-old told NDTV he sat on the ground, "a stone's throw" from the animal, and snapped a couple of photos, but was forced to retreat "within seconds" when the lion noticed him and leapt in his direction.Spoiler:
That's one big, scary kitty cat.
The brilliant tapestry of young stars flaring to life resemble a glittering fireworks display in the 25th anniversary NASA Hubble Space Telescope image, released to commemorate a quarter century of exploring the solar system and beyond since its launch on April 24, 1990.
To capture this image, Hubble’s near-infrared Wide Field Camera 3 pierced through the dusty veil shrouding the stellar nursery, giving astronomers a clear view of the nebula and the dense concentration of stars in the central cluster. The cluster measures between 6 and 13 light-years across.
The giant star cluster is about 2 million years old and contains some of our galaxy’s hottest, brightest and most massive stars. Some of its heftiest stars unleash torrents of ultraviolet light and hurricane-force winds of charged particles etching into the enveloping hydrogen gas cloud.
The nebula reveals a fantasy landscape of pillars, ridges and valleys. The pillars, composed of dense gas and thought to be incubators for new stars, are a few light-years tall and point to the central star cluster. Other dense regions surround the pillars, including reddish-brown filaments of gas and dust.
The brilliant stars sculpt the gaseous terrain of the nebula and help create a successive generation of baby stars. When the stellar winds hit dense walls of gas, the shockwaves may spark a new torrent of star birth along the wall of the cavity. The red dots scattered throughout the landscape are a rich population of newly-forming stars still wrapped in their gas-and-dust cocoons. These tiny, faint stars are between 1 million and 2 million years old -- relatively young stars -- that have not yet ignited the hydrogen in their cores. The brilliant blue stars seen throughout the image are mostly foreground stars.
Because the cluster is very young -- in astronomical terms -- it has not had time to disperse its stars deep into interstellar space, providing astronomers with an opportunity to gather information on how the cluster formed by studying it within its star-birthing environment.
The image’s central region, which contains the star cluster, blends visible-light data taken by Hubble’s Advanced Camera for Surveys with near-infrared exposures taken by the Wide Field Camera 3. The surrounding region is composed of visible-light observations taken by the Advanced Camera for Surveys. Shades of red represent hydrogen and bluish-green hues are predominantly oxygen.
The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington.
Image Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team
Last Updated: April 23, 2015
Editor: Sarah Loff
Tags: http://www.nasa.gov/mission_pages/hubble/main/index.html, http://www.nasa.gov/multimedia/imagegallery/iotd.html, http://www.nasa.gov/subject/6892/stars, http://www.nasa.gov/topics/solarsystem/index.html
IronDog wrote:Happy 25th Hubble Space Telescope
Seeing Deeper: The Webb Space Telescope
The James Webb Space Telescope is NASA's next orbiting observatory and the successor to the Hubble Space Telescope. A tennis court-sized telescope orbiting far beyond Earth's moon, Webb will detect infrared radiation and be capable of seeing in that wavelength as well as Hubble sees in visible light.
Infrared vision is vital to our understanding of the universe. The furthest objects we can detect are seen in infrared light, cooler objects that would otherwise be invisible emit infrared, and infrared light pierces clouds of dust, allowing us to see into their depths. Webb will unleash a torrent of new discoveries, opening the door to a part of the universe that has just begun to take shape under humanity's observations.
Right now, scientists and engineers are piecing Webb together, creating through cutting-edge technology an innovative observatory that not only withstands intense cold, but uses it to its advantage; an observatory that folds up inside a rocket for launch and unfurls like a butterfly opening its wings upon nearing its orbit. Later this decade, the Webb telescope will launch into space, sailing to the distant, isolated orbit where it will begin its quest. Supernovae and black holes, baby galaxies and planets' potential for supporting life — Webb will help reveal the answers to some of the biggest mysteries of astronomy.
A NASA camera on the Deep Space Climate Observatory satellite has returned its first view of the entire sunlit side of Earth from one million miles away.
This color image of Earth was taken by NASA's Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope. The image was generated by combining three separate images to create a photographic-quality image. The camera takes a series of 10 images using different narrowband filters -- from ultraviolet to near infrared -- to produce a variety of science products. The red, green and blue channel images are used in these color images.
The image was taken July 6, 2015, showing North and Central America. The central turquoise areas are shallow seas around the Caribbean islands. This Earth image shows the effects of sunlight scattered by air molecules, giving the image a characteristic bluish tint. The EPIC team is working to remove this atmospheric effect from subsequent images. Once the instrument begins regular data acquisition, EPIC will provide a daily series of Earth images allowing for the first time study of daily variations over the entire globe. These images, available 12 to 36 hours after they are acquired, will be posted to a dedicated web page by September 2015.
The primary objective of DSCOVR, a partnership between NASA, the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Air Force, is to maintain the nation's real-time solar wind monitoring capabilities, which are critical to the accuracy and lead time of space weather alerts and forecasts from NOAA.
For more information about DSCOVR, visit:
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