| Piú viste - Asteroids and Comets |
Tempel1-ZZ-ZL-PIA02132_fig1.jpgThe "Sunny Side" of Comet Tempel-157 visiteCaption originale:"This image composite shows comet Tempel 1 in visible (left) and infrared (right) light. The infrared picture highlights the warm, or sunlit, side of the comet, exactly where NASA's Deep Impact probe hit. These data were acquired about six minutes before impact.
The visible image was taken by the medium-resolution camera on the mission's flyby spacecraft, and the infrared data were acquired by the flyby craft's infrared spectrometer".
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Comets-Schwassmann_Wachmann_1-06.jpgComet Schwassmann-Wachmann 3 and M 5757 visiteMoving rapidly through planet Earth's night sky, Fragment "C" of crumbling comet 73P/Schwassmann-Wachmann 3 passed almost directly in front of M 57 - the "Ring Nebula" - and faint spiral galaxy IC 1296 on May 8, 2006. In fact, in this gorgeous view, the bright head of mentioned Fragment "C" is separated by only about 0,1° from M 57, with the tail apparently engulfing nebula and galaxy.
Recorded from Elizabeth, Illinois, USA, this picture corresponds to the cosmic scene only 30 minutes after yesterday's picture of the approaching alignment. The relative motion of the comet against the background stars and nebulae is easy to see when comparing the two images. This comet's fragments will be near their closest approach in the coming days, about 10 MKM away, and none pose any danger to our fair planet.
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Comets-Schwassmann_Wachmann_1-08.jpgComet Schwassmann-Wachmann 3: the whole "crumbling" Comet (2)57 visitenessun commento
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Asteroids-Asteroid_2002JF56-PIA09230-00.jpgUnknown Asteroid57 visiteUn'immagine non particolarmente suggestiva, ma comunque importante, molto importante: ci arriva dalla Sonda New Horizons che sta calibrando le proprie fotocamere, in attesa (una LUNGA attesa...) di giungere nello Spazio di Plutone e quindi nella Fascia di Kuiper, tra il 2015 ed il 2020...
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![Comets-Halley-Giotto-86hc145[1].jpg](albums/userpics/10008/small_Comets-Halley-Giotto-86hc145%5B1%5D.jpg "Nome del file=Comets-Halley-Giotto-86hc145[1].jpg
Dimensione del file=634KiB
Dimensioni=1756x1788
Aggiunta il=Set 17, 2006")
Comets-Halley-Giotto-86hc145[1].jpgThe "Halley Comet", from Giotto57 visitenessun commento
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McNaught-03.jpgComet McNaught (4)57 visiteCaption NASA:"This past weekend Comet McNaught peaked at a brightness that surpassed even Venus. Fascinated sky enthusiasts in the Earth's Northern Hemisphere were treated to an instantly visible comet head and a faint elongated tail near sunrise and sunset. Recent brightness estimates had Comet McNaught brighter than magnitude - 5 (minus five) over this past weekend, making it the brightest comet since Comet Ikeya-Seki in 1965, which was recorded at - 7 (minus seven). The Great Comet of 2007 reached its brightest as it rounded the Sun well inside the orbit of Mercury. Over the next week Comet McNaught will begin to fade as it moves south and away from the Sun. The unexpectedly bright comet should remain visible to observers in the Southern Hemisphere with unaided eyes for the rest of January.
The above image, vertically compressed, was taken at sunset last Friday from mountains above Catalonia, Spain".
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McNaught-02.jpgComet McNaught (3)57 visiteCaption NASA:" Bright Comet McNaught (C/2006 P1) graced the twilight this week, seen by many and often described with superlatives. Watching the skies over Krakow, Poland, Andrzej Sawow recorded this view on Wednesday - with an ordinary handheld digital camera. He notes that "... astronomy is really for everyone who loves to look at the night sky. And fortunately (sometimes) the sky generously rewards its observer". Now very close to the Sun, Comet McNaught (along with Mercury) is visible in realtime images from the SOHO spacecraft. Otherwise, skywatchers will find the comet hard to see this weekend. But southern hemisphere observers could be rewarded next week as Comet McNaught begins to climb higher in southern skies".
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McNaught-01.jpgComet McNaught (2)57 visiteCaption NASA:"The brightest comet in decades is unexpectedly now visible. The most optimistic predictions have Comet McNaught (C/2006 P1) shortly becoming one of the brightest comets of the past century. For the next few days, its short tail and bright coma can be spotted with the unaided eye close to the Sun and near the horizon in both evening and morning skies. This dramatic picture of the comet shining through cloudy skies was taken near sunset on January 7, 2007, from Bad Mergentheim, Germany".
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McNaught-07.jpgComet McNaught (8)57 visiteCaption NASA:"Comets grow bright when they're close to the Sun, basking in the intense solar radiation. Of course, they're also usually impossible to see against the overwhelming scattered Sunlight. But surprising Comet McNaught - whose January 12, 2007, closest approach to the Sun (perihelion passage) was well inside the orbit of Mercury - gave an enjoyable performance in bright blue daytime skies. In fact, comet expert David Levy captured this remarkable inset (upper left) telescopic view of McNaught within an hour of perihelion, with the comet in broad daylight only about 7° away from the Sun's position.
Stefan Seip's wider daytime view of the comet and fluffy clouds was recorded approximately a day later. Seip used a polarizing filter and a telescope/camera set up near Stuttgart, Germany.
No longer visible in broad daylight, Comet McNaught is now touring twilight Southern Skies".
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McNaught-9.jpgComet McNaught (10)57 visiteCaption NASA:"By January 19/20, 2007, Comet McNaught's magnificent dust tail stretched for about 150 MKM (~1 AU), requiring images from both Southern and Northern Hemispheres of planet Earth to take it all in. Two such views - from Cerro Paranal in Chile (left) and the Carnic Alps in Italy - are combined in this unique graphic that also outlines a perspective view of the Comet's orbit (dotted line) and relative position of the Sun. Driven by solar radiation pressure the dust tail initially points away from the Sun, but also trails outside the comet's orbit. Astronomers try to account for the complex structure along the tail, including the pronounced striations, by considering forces acting on the dust (e.g. gravity, solar wind and radiation) as well as the release time and size of the dust grains. In the diagram, the modeled location of dust grains released at approximately the same time relative to perihelion passage, synchrones, are shown as dashed lines. The location of grains of similar size, syndynes, are shown as solid lines".
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Comets-Comet_Holmes.jpgComet 17-P-Holmes57 visiteCaption NASA, da "NASA - Picture of the Day" del 26 Ottobre 2007:"Comet 17 P-Holmes stunned comet watchers across planet Earth earlier this week.
On October 24th, 2007, it increased in brightness over half a million times in a matter of hours. The outburst transformed it from an obscure and faint comet quietly orbiting the Sun with a period of about 7 years to a naked-eye comet rivaling the brighter stars in the constellation of Perseus. Recorded on that date, this view from Teheran, Iran, highlights the comet's (enhanced and circled) dramatic new visibility in urban skies.
The inset (left) is a telescopic image from a backyard in Buffalo, New York showing the comet's greatly expanded coma, but apparent lack of a tail. Holmes' outburst could be due to a sudden exposure of fresh cometary ice or even the breakup of the comet nucleus. The comet may well remain bright in the coming days".MareKromium
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LLO-Itokawa-ST_2563511720_v.jpgThe unbelievable surface of 25143-Itokawa (HR5 - possible natural colors; elab. Lunexit)57 visitenessun commentoMareKromium
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