Nightcliff, Northern Territory, Australia
Image Credit & Copyright: Cathryn Vasseleu
February 18, 2017
International Space Station
Backdropped by rugged Earth terrain, the International Space Station is featured in this image photographed by an STS-130 crew member on space shuttle Endeavour after the station and shuttle began their post-undocking relative separation. Undocking of the two spacecraft occurred at 7:54 p.m. (EST) on February 19, 2010.
Space Shuttle Endeavour, Orbit of the Earth
February 19, 2010
Image Credit: NASA
Emission Nebula RCW 79
RCW 79 is seen in the southern Milky Way, 17,200 light-years from Earth in the constellation Centaurus. The bubble is 70-light years in diameter, and probably took about one million years to form from the radiation and winds of hot young stars.
The balloon of gas and dust is an example of stimulated star formation. Such stars are born when the hot bubble expands into the interstellar gas and dust around it. RCW 79 has spawned at least two groups of new stars along the edge of the large bubble. Some are visible inside the small bubble in the lower left corner. Another group of baby stars appears near the opening at the top.
Image Credit: NASA/JPL-Caltech/E. Churchwell (University of Wisconsin-Madison)
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA07841
February 17, 2017
Rainbow and Lightning over Iowa
Mount Pleasant, Iowa, USA
May 21, 2016
Image Credit & Copyright: Paul Brooks
Earth and the International Space Station seen from Space Shuttle Endeavour
Backdropped by Earth's horizon and the blackness of space, the International Space Station is featured in this image photographed by an STS-130 crew member on space shuttle Endeavour after the station and shuttle began their post-undocking relative separation. Undocking of the two spacecraft occurred at 7:54 p.m. (EST) on February 19, 2010.
Space Shuttle Endeavour, Orbit of the Earth
February 19, 2010
Image Credit: NASA
Mountains of Creation
The image composite compares an infrared image taken by NASA's Spitzer Space Telescope to a visible-light picture of the same region (inset). While the infrared view, dubbed "Mountains of Creation," reveals towering pillars of dust aglow with the light of embryonic stars (white/yellow), the visible-light view shows dark, barely-visible pillars. The added detail in the Spitzer image reveals a dynamic region in the process of evolving and creating new stellar life.
Why do the pictures look so different? The answer has two parts. First, infrared light can travel through dust, while visible light is blocked by it. In this case, infrared light from the stars tucked inside the dusty pillars is escaping and being detected by Spitzer. Second, the dust making up the pillars has been warmed by stars and consequently glows in infrared light, where Spitzer can see it. This is a bit like seeing warm bodies at night with infrared goggles. In summary, Spitzer is both seeing, and seeing through, the dust.
Image Credit: NASA/JPL-Caltech/L. Allen (Harvard-Smithsonian CfA)
Explanation from: https://www.nasa.gov/multimedia/imagegallery/image_feature_483.html
February 16, 2017
Lightning over Courthouse Rock
Courthouse Rock in Arches National Park, Utah, USA
Image Credit & Copyright:Raul Touzon
The Carina Nebula
Composed of gas and dust, the pictured pillar resides in a tempestuous stellar nursery called the Carina Nebula, located 7500 light-years away in the southern constellation of Carina.
Taken in visible light, the image shows the tip of the three-light-year-long pillar, bathed in the glow of light from hot, massive stars off the top of the image. Scorching radiation and fast winds (streams of charged particles) from these stars are sculpting the pillar and causing new stars to form within it. Streamers of gas and dust can be seen flowing off the top of the structure.
Hubble's Wide Field Camera 3 observed the Carina Nebula on 24-30 July 2009. WFC3 was installed aboard Hubble in May 2009 during Servicing Mission 4. The composite image was made from filters that isolate emission from iron, magnesium, oxygen, hydrogen and sulphur.
These Hubble observations of the Carina Nebula are part of the Hubble Servicing Mission 4 Early Release Observations.
Image Credit: NASA, ESA and the Hubble SM4 ERO Team
Explanation from: http://www.spacetelescope.org/images/heic0910e/
Galaxy Cluster MACS J0025.4-1222
This astounding view of galaxy cluster MACSJ0025 demonstrates how ordinary matter and mysterious dark matter interact. The blue cloud-shaped parts flanking the centre show the position of dark matter, mapped by the Advanced Camera for Surveys onboard the NASA/ESA Hubble Space Telescope. The pink middle indicates ordinary matter, charted by NASA's Chandra X-Ray Observatory.
The position of the two matter types shown in the image are explained by MACSJ0025's origin. It was formed when a pair of large galaxy clusters collided. Ordinary matter in the form of hot gas slowed down and pooled at the centre but ghostly dark matter passed straight through.
Hubble used a technique known as gravitational lensing to obtain its data. The light observed was bent by the gravitationally massive galaxy cluster, resulting in an incredibly detailed image. This technique was originally predicted by Einstein.
MACSJ0025 is located in the constellation Cetus, the Whale.
Image Credit: NASA, ESA, CXC, M. Bradac (University of California, Santa Barbara, USA), and S. Allen (Stanford University, USA)
Explanation from: https://www.spacetelescope.org/images/heic0818a/
February 15, 2017
Kepler-69c
The artist's concept depicts Kepler-69c, a super-Earth-size planet in the habitable zone of a star like our Sun, located about 2,700 light-years from Earth in the constellation Cygnus.
Kepler-69c, is 70 percent larger than the size of Earth, and is the smallest yet found to orbit in the habitable zone of a Sun-like star. Astronomers are uncertain about the composition of Kepler-69c, but its orbit of 242 days around a sun-like star resembles that of our neighboring planet Venus.
Image Credit: NASA/Ames/JPL-Caltech
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA17003
Globular Cluster Messier 72
This rich collection of scattered stars, known as Messier 72, looks like a city seen from an airplane window at night, as small glints of light from suburban homes dot the outskirts of the bright city centre. Messier 72 is actually a globular cluster, an ancient spherical collection of old stars packed much closer together at its centre, like buildings in the heart of a city compared to less urban areas. As well as huge numbers of stars in the cluster itself the picture also captures the images of many much more distant galaxies seen between and around the cluster stars.
French astronomer Pierre Méchain discovered this rich cluster in August of 1780, but we take Messier 72’s most common name from Méchain’s colleague Charles Messier, who recorded it as the 72nd entry in his famous catalogue of comet-like objects just two months later. This globular cluster lies in the constellation of Aquarius (the Water Bearer) about 50 000 light-years from Earth.
This striking image was taken with the Wide Field Channel of the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope. The image was created from pictures taken through yellow and near-infrared filters (F606W and F814W). The exposure times were about ten minutes per filter and the field of view is about 3.4 arcminutes across.
Image Credit: ESA/Hubble & NASA
Explanation from: https://www.spacetelescope.org/images/potw1001a/
February 14, 2017
Cumulonimbus Cloud over Africa seen from the International Space Station
High above the African continent, tall, dense cumulonimbus clouds, meaning 'column rain' in Latin, are the result of atmospheric instability. The clouds can form alone, in clusters, or along a cold front in a squall line. The high energy of these storms is associated with heavy precipitation, lightning, high wind speeds and tornadoes.
Image Credit: NASA
Star IRAS 19475+3119
This Hubble Space Telescope picture captures a brief but beautiful phase late in the life of a star. The curious cloud around this bright star is called IRAS 19475+3119. It lies in the constellation of Cygnus (the Swan) about 15 000 light-years from Earth in the plane of our Milky Way galaxy.
As stars similar to the Sun age they swell into red giant stars and when this phase ends they start to shed their atmospheres into space. The surroundings become rich in dust and the star is still relatively cool. At this point the cloud shines by reflecting the brilliant light of the central star and the warm dust gives off lots of infrared radiation. It was this infrared radiation that was detected by the IRAS satellite in 1983 and brought the object to the attention of astronomers. Jets from the star may create strange hollow lobes, and in the case of IRAS 19475+3119 two such features appear at different angles. These curious objects are rare and short-lived.
As the star continues to shed material the hotter core is gradually revealed. The intense ultraviolet radiation causes the surrounding gas to glow brilliantly and a planetary nebula is born. The objects that come before planetary nebulae, such as IRAS 19475+3119, are known as preplanetary nebulae, or protoplanetary nebulae. They have nothing to do with planets — the name planetary nebula arose as they looked rather like the outer planets Uranus and Neptune when seen through small telescopes.
This image was created from images taken using the High Resolution Channel of the Hubble Space Telescope’s Advanced Camera for Surveys. The red light was captured through a filter letting through yellow and red light (F606W) and the blue was recorded through a standard blue filter (F435W). The green layer of the image was created by combining the blue and red images. The total exposure times were 24 s and 245 s for red and blue respectively. The field of view is about twenty arcseconds across.
Image Credit: ESA/Hubble and NASA
Explanation from: https://www.spacetelescope.org/images/potw1012a/
February 13, 2017
Comet Lovejoy seen from the International Space Station
In November and December 2011, professional and amateur astronomers reveled in observing a sun-grazing comet that dove close to the Sun and survived for a return flight back to the outer solar system. Astronauts on the International Space Station (ISS) enjoyed their own surreal view of the comet as it appeared on Earth’s horizon on the day of the solstice.
ISS Commander Dan Burbank captured a series of digital photographs of Comet Lovejoy on December 21, 2011, as it rose above Earth’s limb. The ISS was passing from eastern Australia southeast toward New Zealand, between 17:35:50 to 17:43:02 Universal Time (6:35 to 6:43 a.m. local time on December 22). In an interview with WDIV-TV, Burbank described the moment as “the most amazing thing I have ever seen in space.”
Note how the tail of the comet points away from the Sun even as the comet itself is moving in the same direction, away from our star. Every comet has two tails, one of ice and dust, the other of ions, or charged particles. The heat and pressure of sunlight sloughs off the ice and dust, pushing it away from the Sun. Likewise, the solar wind strips ions off of the comet surface, though not necessarily in the same direction as the tail of debris and ice. The ion tail is not visible in this image.
The comet, officially designated C/2011 W3 (Lovejoy), was discovered by Australian amateur astronomer Terry Lovejoy on November 27, 2011. It belongs to a group of comets known as the Kreutz sungrazers, which are thought to be pieces of a much larger comet that broke up centuries ago. The comets are termed sungrazers because their orbits take them quite near—and often into—the Sun.
Comet Lovejoy is remarkable for diving through the superheated solar corona (atmosphere) to within 120,000 kilometers of the Sun’s surface and surviving the encounter. The event was recorded by five NASA and European spacecraft.
In the ISS image you can also see green and yellow airglow paralleling the Earth’s horizon line (or limb) before it is overwhelmed by the light of the rising Sun. Airglow is the emission of light by atoms and molecules in the upper atmosphere after they are excited by ultraviolet radiation.
Image Credit: NASA
Explanation from: http://visibleearth.nasa.gov/view.php?id=76853
Lenticular Galaxy NGC 4452
The NASA/ESA Hubble Space Telescope has imaged a striking galaxy called NGC 4452, which appears to lie exactly edge-on as seen from Earth. The result is an extraordinary picture of billions of stars observed from an unusual angle. The bright nucleus can be seen at the centre, along with the very thin disc that looks like a straight line from our unusual viewing position. To complete the picture, a hazy halo of stars on the periphery of the galaxy makes it seem to glow.
NGC 4452 was first seen by William Herschel in 1784 with his 47 cm telescope in England. He described the object as a bright nebula, small and very much elongated. The new Hubble image shows just how elongated this unusual object really is.
Galaxies are like star cities, and typically contain many billions of stars. The American astronomer Edwin Hubble, after whom the Hubble Space Telescope is named, was the first person to prove that there are other galaxies beyond our own by measuring their distances. This work, done in the 1920s, forever changed our view of the Universe.
Galaxies also belong to collections that are called galaxy clusters. NGC 4452 is part of the Virgo Cluster, so-called because many of its members appear in the constellation of Virgo (the Maiden). This enormous grouping is approximately 60 million light-years distant and contains around 2000 galaxies.
It is thought that the Local Group of galaxies, to which our own Milky Way belongs, is on the fringes of the Virgo Cluster, and at some point in the far future the Local Group may be pulled slowly into the Virgo Cluster by the force of gravity. Large numbers of much more remote, faint galaxies, far beyond NGC 4452 and the Virgo Cluster, appear in the background of this image.
This picture of NGC 4452 was created from images taken using the Wide Field Channel on Hubble’s Advanced Camera for Surveys. This picture was made from images through blue (F475W, coloured blue) and near-infrared (F850LP, coloured red) filters. The exposures times were 750 s and 1210 s respectively. The field of view extends over 2.6 arcminutes.
Image Credit: ESA/Hubble & NASA
Explanation from: https://www.spacetelescope.org/images/potw1029a/
