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| Risultati della ricerca nelle immagini - "views" |
006-Ceres.jpg1-Ceres (natural colors, from HST - credits: NASA/ESA et al.)53 visiteThe Hubble image of Ceres on the reveals bright and dark regions on the asteroid's surface that could be topographic features, such as craters, and/or areas containing different surface material. Large impacts may have caused some of these features and potentially added new material to the landscape. The Texas-sized asteroid holds about 30 to 40% of the mass in the Asteroid Belt.
Ceres' round shape suggests that its interior is layered like those of terrestrial planets such as Earth. The asteroid may have a rocky inner core, an icy mantle, and a thin, dusty outer crust. The asteroid may even have water locked beneath its surface. It is approx. 590 miles (950 Km) across and was the first asteroid discovered in 1801.
The observation was made in visible and ultraviolet light between December 2003 and January 2004 with the HST Advanced Camera for Surveys. The color variations in the image show either a difference in texture or composition on Ceres' surface.
Astronomers need the close-up views of the Dawn spacecraft to determine the characteristics of these regional differences.
MareKromium
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016-Mars_Altitudes.jpgMars "Ups and Downs"...56 visiteTo complement the MOLA Laser Altimeter Mercator maps of Mars' elevations and topography, the MOLA Team also produced views of selected hemispheres.
These views emphasize specific interesting areas or angles. These maps show altitude data coded into colors - blue is low and red/white are high.
These two hemispheres are centered on the Tharsis Plateau (including the Valles Marineris and the large volcanos) and on the Isidis Impact Basin (with the Hellas Basin to the South).MareKromium
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017-The Moon from Clem-NearSide-PIA00302.jpg003 - The Near-Side of the Moon55 visiteAbout 50.000 Clem images were processed to produce the 4 orthographic views of the Moon. Images PIA00302, PIA00303, PIA00304 and PIA00305 show albedo variations (normalized brightness or reflectivity) of the surface at a wavelength of 750 nm (just longward of visible red). The Lunar Near-Side is a contrast between dark and light albedo surfaces that has been fancied as the "Man in the Moon". Lunar terrain types are still designated by their 17th century name and that is:
1. Maria (dark albedo features also known as basins) and
2. Terra (brighter albedo features also known as uplands or highlands).
The Maria constitutes about 16% while the Terra 84% of the Lunar Surface. The nearside is composed of about 30 percent maria. Extensive bright ray systems surround craters Copernicus (upper left center) and Tycho (near bottom).
Studies have shown that two major processes, impact and basaltic volcanism have shaped the major physical features of the Lunar Surface.
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018-Vesta-6-PIA13428.jpgSome of the "Faces" of 4-Vesta, from Hubble Space Telescope95 visiteNASA's Hubble Space Telescope snapped these images of the Asteroid 4-Vesta in preparation for the Dawn Spacecraft's visit in 2011. Each of the 4 Hubble images captures views of Vesta during its 5,34-hour rotation period. Hubble's sharp "eye" can see features as small as about 40 Km (24,84 miles) across in these images. Vesta was 211 MKM (approx. 131 MMs) from Earth when Hubble made the observations.
The images show the difference in brightness and color on the Asteroid's Surface. These characteristics hint at the large-scale features that the Dawn Spacecraft will see when it visits the potato-shaped asteroid.
Astronomers used the images, taken with Hubble's Wide Field Camera 3, to better determine 4-Vesta's Spin Axis. Based on the HST observations, astronomers calculated a slightly different, and more precise, Rotation Axis for Vesta. The new calculation will change the pattern of sunlight expected to illuminate the Asteroid when Dawn arrives.
Determining a more accurate Spin Axis for 4-Vesta will also help scientists refine the Dawn Spacecraft's orbit around the Asteroid. Dawn will orbit the rocky object for a year, beginning in July 2011. The Spacecraft will then travel to the "Dwarf Planet" 1-Ceres, arriving in 2015.
Hubble has kept its "eye" on 4-Vesta for more than 15 years, beginning in 1994. Hubble images of 4-Vesta in 1997 helped astronomers discover the Asteroid's very large Impact crater. Astronomers combined views of 4-Vesta in Near-UltraViolet and blue light to construct these images and the images were taken on Feb. 25, 2010.MareKromium
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1-Venus_Galileo_Visible.jpgVenus136 visiteUna magnifica ricostruzione di Venere - ad opera dello "Space Artist" Don P. Mitchell - nei colori in cui un umano che fosse nello spazio la vedrebbe.
Queste le annotazioni originali dell'Artista:
Full spectral data is rarely available, and instead we must use views through color filters. Above, the Galileo probe captured Venus through a clear filter (left) and through a 410 nm violet filter, which reveals the subtle yellow and white clouds. Unfortunately, many different color images could result in the same two clear and violet signals above. Even when so-called red, green and blue filters are used, the problem is just as difficult, because the filters are not really the right red, green and blue to just plug into the channels of a color display. Theoretically, information from the two images above and from the Cassini spectrum could be combined using Bayesian decision theory, to compute the most probable color image. If colors are estimated correctly, there is a final issue of tone mapping. How bright does the image appear to the eye in a given context. The image above is the best color image of Venus I've found, showing the planet as it would likely appear to a human observer in space. It was made by Turkish astronomer A. Tayfun Oner, using the two color channels from the Galileo camera, and a third interpolated channel.
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19981223.jpgViews of 433-Eros53 visiteThis montage of images of the asteroid Eros was assembled from images acquired by the Near Earth Asteroid Rendezvous (NEAR) Spacecraft on December 23, 1998, as the Spacecraft flew by the asteroid at a distance of 2300 miles (3800 Km) at 1:43 PM EST. Shown are nine early views out of 29 that were obtained during the flyby. These images were taken between 10:44 AM and 12:44 PM EST, as the Spacecraft range closed from 7300 miles (such as abou 11.100) Km, to 3300 miles (such as approx. 5300 Km).
During that time, the Asteroid completed nearly half of a rotation. The smallest resolved detail is approximately 1650 feet (500 meters) across.
A firing of the main engine at 17:00, EST, on December 20, 1998, designed to slow the Spacecraft for insertion into orbit around the Asteroid, was aborted by the Spacecraft. Contact with ground controllers was temporarily lost, but was regained at 20:00 EST on December 21, when autonomous Spacecraft safety protocols took over and transmitted a signal to the ground. All spacecraft systems were determined to be healthy and operational.
Within hours, a flyby observation sequence was developed and uploaded to the Spacecraft.
1026 images were acquired by the Multispectral Imager, to determine the size, shape, morphology, rotational state, and color properties of Eros, and to search for small moons.
The Infrared Spectrometer measured spectral properties of the Asteroid to determine what minerals were present, and the Magnetometer searched for a natural Magnetic Field.
Analysis of the Spacecraft radio signal were also used to determine the asteroid's mass and density.
The main engine was fired successfully on January 3, 1999, placing NEAR on-course for a February 2000 rendezvous.
Eros is NEAR's second asteroid encountered. On June 27, 1997, NEAR flew by the Main-Belt Asteroid Mathilde at a range of approx. 1212 Km (750 miles).MareKromium
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19990108.jpg433-Eros52 visiteThis pair of images of the Asteroid 433-Eros was acquired by the Near Earth Asteroid Rendezvous (NEAR) Spacecraft on December 23, 1998, as the Spacecraft flew by the night side of the Asteroid at a distance of about 2300 miles (approx. 3800 Km) at 13:43 EST. These views, taken at 13:44 and 14:05 EST, as the Spacecraft range increased from 2300 miles to 2500 miles (about 4100 Km), show only a tiny portion of the day side of Eros (Phase Angle ~119).
The smallest resolved detail in this frame is approximately 1300 feet (400 meters) across. MareKromium
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20000410.jpgDifferent Lights, Different Visions52 visiteDuring the 28 days the NEAR Shoemaker Spacecraft circled Eros in a 200-Km (such as approx. 124-mile) altitude orbit, it imaged parts of the surface under a variety of lighting and viewing conditions.
The different views of the surface allow study of small-scale morphology, analysis of albedo and color variations, and construction of topographic models from stereo images.
This image, taken April 2, 2000, from a range of 199 Km (about 123 miles), shows the effects of lighting changes. At the bottom of the frame, sunlight illuminates the surface at a grazing angle. The strong shadows bring out subtle landforms like the gentle undulations in the surface, visible at the lower center.
At the top of the frame, sunlight strikes the surface at a high angle and shadows become subdued, bringing out brightness variations like those on the wall of the large, 5,5-Km (3,4-mile) diameter crater at left.
(Image 0130112939)MareKromium
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23-Farside-Luna3.jpgThe Moon from "Luna 3"55 visiteCaption NASA originale:"The Luna 3 spacecraft returned the first views ever of the far side of the Moon. The first image was taken at 03:30 UT on 7 October 1959 at a distance of 63.500 Km after Luna 3 had passed the Moon and looked back at the sunlit far side. The last image was taken 40 minutes later from 66.700 Km. A total of 29 photographs were taken, covering 70% of the far side. The photographs were very noisy and of low resolution, but many features could be recognized. This close up view taken with the narrow angle camera shows the far side has fewer maria (the dark areas) than the near side. The image is centered at 20 N, 95 E and the dark area to the left and just below center is Mare Marginus and below that Mare Smythii, just at the boundary between the near and far sides. The left half of the image shows the near side of the Moon, including the circular Mare Crisium at far left (Luna 3-26)".
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24-Farside-Luna3.jpgThe Far-Side of the Moon from "Luna 3"52 visiteCaption NASA originale:"The Luna 3 spacecraft returned the first views ever of the far side of the Moon. The first image was taken at 03:30 UT on 7 October at a distance of 63,500 km after Luna 3 had passed the Moon and looked back at the sunlit far side. The last image was taken 40 minutes later from 66,700 km. A total of 29 photographs were taken, covering 70% of the far side. The photographs were very noisy and of low resolution, but many features could be recognized. This close up view taken with the narrow angle camera shows the far side has fewer maria (the dark areas) than the near side. The image is centered at 20 N, 95 E and the dark area to the left and just below center is Mare Marginus and below that Mare Smythii, just at the boundary between the near and far sides. The left half of the image shows the near side of the Moon, including the circular Mare Crisium at far left. The Moon is 3475 km in diameter and north is up (Luna 3-27)".
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47 Ursae Majoris.jpg47 Ursae Majoris b290 visite"...Mentre lo stringevo a me, sentivo il suo cuore battere pi forte che mai: e sentivo che c'era l'energia di un intero Universo in quel cuore gonfio e pulsante; c'era energia e c'era paura.
Non potevo guardare il suo volto (anche a causa della posizione che avevo assunto per bloccarlo), ma avevo la sensazione che i suoi occhi fossero sgranati, aperti su quello che stava accadendo ed alla ricerca di risposte che - e lui lo sapeva - sarebbero anche potute non giungere mai.
Io lo tenevo e lui si lasciava tenere. Di tanto in tanto sembrava volesse tentare una fuga, ma senza averne la giusta convinzione.
Era un mondo strano, quel suo mondo: io lo stavo aiutando, ma lui sembrava aver paura del mio aiuto.
Forse aveva solo paura di me, poich sapeva da dove venivo..."
P.C. Floegers - "Memorie di Viaggio"
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55 Cancri-2.jpg55 Cancri and one of its planets260 visiteL'azione congiunta di 3 osservatori (Hobby-Eberly, Lick ed HST) ha permesso la scoperta di un nuovo pianeta che ruota attorno alla stella denominata "55 Cancri", distante solo 40 a.l. da noi. Questo pianeta (il quarto del Sistema) pare possedere la massa di Nettuno, ma ruota molto vicino alla sua stella madre, in un orbita addirittura inferiore a quella che, nel nostro Sistema, occupa Mercurio. Noi riteniamo che, da una tale situazione, dovrebbe derivare l'assoluta instabilit dell'orbita di questo pianeta e, forse, dellintero Sistema a cui esso accede.
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