Pesquisando por: "Formation of the Moon" - Fotoarena - Agência de fotojornalismo

PIX4625409 Japet, satellite of Saturn, seen by Cassini - Saturn's moon Iapetus seen by Cassini spacecraft - Comparison of the two hemispheres of Japet, a satellite of Saturn of 1471 kilometres in diameter. Its main feature is the color difference between the two hemispheres. On the left, the dark region called Cassini Regio with to the east the largest crater of Japet, named Turgis (580 km in diameter). On the right, the bright side of the satellite with Roncevaux Terra (north) and Saragossa Terra (south) housing the large impact crater Engelier (504 km in diameter). Both images were obtained by the Cassini probe on 10 September 2007 (right) and 27 December 2004 (left). These two global images of Iapetus show the extreme brightness dichotomy on the surface of this peculiar Saturnian moon. The left - hand panel shows the moon's leading hemisphere and the right - hand panel shows the moon's trailing side. While low and mid latitudes of the leading side exhibit a surface almost as dark as charcoal, broad tracts of the trailing side are almost as bright as snow. The dark terrain covers about 40 percent of the surface and is named Cassini Regio. The names of the bright terrain are Roncesvaux Terra (north) and Saragossa Terra (south). On both hemispheres, the dominant landforms are impact craters. The largest known well - preserved basin on Iapetus, called Turgis, has a diameter of about 580 kilometers (360 miles). It lies at 17 degrees north latitude, 28 degrees west longitude at the eastern edge of the dark Cassini Regio and is visible on the right side of the left - hand panel. The prominent basin on the southern trailing side (at the lower left of the right - hand panel) is Engelier. Engelier is located at 41 degrees south latitude, 265 degrees west longitude, and has a diameter of about 504 kilometers (313 miles). Its formation destroyed about half of Gerin, another large basin on Iapetus. Gerin is located at 46 degrees south latitude, 233 degrees

PIX4621545 Formation d'etoiles dans les Voiles - Star formation in Vela - Vue en infrarouge des nebuleuses Gum 22 (en haut a droite), Gum 23, IRAS 09002 - 4732 (nuage orange pres du centre), Bran 226 (vers le bas a gauche), et Gum 25 (tout en bas a gauche). Ces regions de formation d'etoiles sont situees entre 4000 et 10 000 annees - lumiere de la Terre. L'etoile verte tres brillante, vers le bas a droite de l'image, est une etoile carbonee, IRAS 08535 - 4724. Image obtenue par le telescope WISE (Wide - field Infrared Explorer). This image from NASA's Wide - field Infrared Survey Explorer, or WISE, highlights several star - forming regions. There are five distinct centers of star birth in this one image alone. Star - forming nebulae (called HII regions by astronomers) are clouds of gas and dust that have been heated up by nearby stars recently formed from the same cloud. The largest, brightest cloud, in the upper right is known as Gum 22. It's named after Colin Gum, an Australian astronomer who surveyed the southern hemisphere sky in the early 1950's looking for star - forming regions like these. He catalogued 85 new such regions, named Gum 1 to85 (Gum Crater on the moon was also named in his honor). Going counter - clockwise from Gum 22, the other catalogued nebulae in the image are Gum 23 (part of same cloud as 22), IRAS 09002 - 4732 (orange cloud near center), Bran 226 (upper cloud of the two at lower left), and finally Gum 25 at far lower left. There are also several smaller and/or more distant regions scattered throughout the image that have yet to be catalogued. Most of the regions are thought to be part of our local Orion spiral arm spur in the Milky Way galaxy. Their distances range from about 4,000 to 10,000 light - years away. Notice the very bright green star near the lower right portion of the image. You can tell it's a star because it appears to have 'spikes' sticking out of it (diffraction spikes like these are an optical effect caused by the structure of the te

PIX4565700 Galaxy cluster Abell 2667 - Galaxy cluster Abell 2667 - In this image of the galaxy cluster Abell 2667, a spiral galaxy, at the top left of the image, seems to leave a trail of gas and stars in its wake. Attracted by the high gravity of Abell 2667, this “galaxy - comete” plunges into the cluster at a speed of 3.5 million km/h, losing its gas and young stars. This phenomene may explain the presence of isolated stars in the centre of galaxy clusters. On the right, a further galaxy appears as a gravitational arc. Image obtained by the Hubble Space Telescope in October 2001. The NASA/ESA Hubble Space Telescope, in collaboration with several other ground - and space - based telescopes, has captured a galaxy being ripped apart by a galaxy cluster's gravitational field and harsh environment. The finding sheds light on the mysterious process by which gas - rich spiral - shaped galaxies might evolve into gas - poor irregular - or elliptical - shaped galaxies over billions of years. The new observations also show one mechanism to form the millions of 'homeless' stars seen scattered throughout galaxy clusters. While looking at the galaxy cluster Abell 2667, astronomers found an odd - looking spiral galaxy (shown here in the upper left hand corner of the image) that ploughs through the cluster after being accelerated to at least 3.5 million km/h by the enormous combined gravity of the cluster's dark matter, hot gas and hundreds of galaxies. As the galaxy speeds through, its gas and stars are being stripped away by the tidal forces exerted by the cluster just as the tidal forces exerted by the moon and Sun push and pull the Earth's oceans. Also contributing to this destructive process is the pressure of the cluster's hot gas plasma reaching temperatures as high as 10 - 100 million degrees. Both processes the tidal forces and the aptly named 'ram pressure stripping' resulting from the action of the hot clust

PIX4637984 Galactic Center Region - The Galactic Center - The Galactic Center Region of the center of our galaxy seen the Chandra, Spitzer and Hubble satellites. The galactic center (Sagittarius A*) is located in the white area in the middle to the right of the image. In yellow, near-infrared images obtained by the Hubble Space Telescope; in red, infrared images obtained by the Spitzer Space Telescope; in blue and purple, X-ray observations obtained by the Chandra Space Telescope. Nasa's Great Observatories - the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory - have collaborated to produce an unprecedented image of the central region of our Milky Way galaxy. In this spectacular image, observations using infrared light and X-ray light see through the obscuring dust and reveal the intense activity near the galactic core. Note that the center of the galaxy is located within the bright white region to the right of and just below the middle of the image. The entire image width covers about one-half a degree, about the same angular width as the full moon. Each telescope's contribution is presented in a different color: - Yellow represents the near-infrared observations of Hubble. These observations outline the energetic regions where stars are being born as well as reveal hundreds of thousands of stars. - Red represents the infrared observations of Spitzer. The radiation and winds from stars create glowing dust clouds that exhibit complex structures from compact, spherical globules to long, stringy filaments. - Blue and violet represent the X-ray observations of Chandra. X-rays are emitted by gas heated to millions of degrees by stellar explosions and by outflows from the supermassive black hole in the galaxy's center. The bright blue blob on the left side is emission from a double star system containing either a neutron star or a black hole. When these views are brought together, this composite image provides one of the most detailed