|
|
EROS-G-TouchDown.jpg433 Eros: 4 years after the "touch-down"!64 visiteCaption da "NASA - Picture of the Day" del 12.02.2005:"On 12 February, 2001, the NEAR-Shoemaker spacecraft gently touched-down on the the surface of Eros - the first ever landing on an asteroid. During the descent, the spacecraft's camera recorded successive images of the diminutive world's surface, revealing fractured boulders, dust filled craters, and a mysterious collapsed channel. The last frame, seen in the above montage at the far left, was taken at a range of 128 meters. Expanded in the inset, it shows surface features a few centimeters across. Stereo experimenter Patrick Vantuyne, constructed this montage from the final images in the landing sequence, carefully identifying the overlapping areas in successive frames. Frames which overlap were taken by the spacecraft from slightly different viewpoints, allowing Vantuyne to construct close-up stereo images of the surface of asteroid 433 Eros".
|
|
EROS-GIFMovie-049.gifRolling and Floating: 433-Eros (GIF-Movie; credits: Dr G. Barca)64 visitenessun commentoMareKromium
|
|
EROS-GIFMovie-050_frame02.gifRolling and Floating: 433-Eros (GIF-Movie; credits: Dr G. Barca)65 visitenessun commentoMareKromium
|
|
EROS-GIFMovie-051.gif433-Eros: features in motion! (GIF-Movie; credits: Dr G. Barca)67 visitenessun commentoMareKromium
|
|
EROS-PIA02492.jpgEros in true colors96 visiteAs the NEAR Shoemaker spacecraft descends into lower orbits around Eros, it continually returns higher spatial resolution images of the asteroid. The true color image at left was taken February 12, 2000, from a range of 1.748 Km and shows details only as small as 180 meters (590 feet) across. It was taken two days before orbit insertion, as part of an image sequence designed to provide moderate-resolution color mapping of Eros at a near-constant viewing geometry. The true color image inset at right was taken February 29 from a range of 283 Km and shows much smaller details only 27 meters (89 feet) across.
|
|
EROS-PIA02493_modest.jpgSunset on Eros67 visiteEros' irregular shape gives rise to some stunning vistas at the time of sunrise or sunset. On March 6, 2000, the imager on the NEAR Shoemaker spacecraft caught this view of a stunning sunset. In the pitch black foreground the Sun has already set, but just over the horizon another part of the asteroid remains lit. Eros' rotation period is just 5 hours, 16 minutes, so in the course one 24-hour Earth day an observer on Eros would be treated to four full cycles of sunrises and sunsets.
|
|
EROS-PIA02901_modest.jpgCraters on the limb of Eros64 visiteIn this image, taken April 17, 2000, from a height of 101 Km (63 miles), the shadows highlight small-scale surface features. The surface is pockmarked with craters ranging in size up to the 2,8 Km (1,74 mile) diameter crater in the center of the image. The smallest craters which can be resolved are about 20 meters (65 feet) across. In lower right corner of the image, 20-meter boulders can be seen that were not evident in images from higher altitudes.
|
|
EROS-PIA02905-0.jpgEros (the BIG Pseudo-Anomaly)162 visiteThis image of Eros, taken from the NEAR Shoemaker spacecraft on May 1, 2000, is among the first to be returned from "low orbit." Between May and August, the spacecraft orbited at altitudes near 50 Km or less. This will be the prime period of activity for some of the spacecraft's science instruments. The X-ray / gamma-ray spectrometer will build up maps of chemical abundances, while the laser rangefinder measures the shape of Eros to within meters (a few feet). At the same time the magnetometer will watch for indications of Eros' magnetic field and the near-infrared spectrometer will map rock types. The imager will take pictures of the entire surface of Eros that capture features as small as 4 meters (13 feet) across. This particular image, taken from an orbital altitude of 53 Km, shows a scene about 1.8 Km across. Numerous craters and boulders as small as 8 meters (26 feet) across dot the landscape. The large, rectangular boulder at the upper right is about 45 meters across.
|
|
EROS-PIA02905-1.jpgEros (Position of the BIG Pseudo-Anomaly)68 visitenessun commentoMareKromium
|
|
EROS-PIA02906_modest.jpgHorizon view79 visiteThis image of Eros, taken from the NEAR Shoemaker spacecraft on May 2, 2000, from an orbital altitude of 52 kilometers (32 miles), shows a view toward Eros' horizon. The section shown is about 1.8 kilometers (1.1 miles) across. This particular view provides a snapshot of three of the most common types of features seen on the asteroid: craters whose rims have been rounded by erosion due to smaller impacts and blanketing by the impact debris, or regolith (impact debris); variations in the brightness of material on the walls of the craters; and a scattering of boulders ranging in size from nearly 100 meters (328 feet) down to about 8 meters (26 feet).
|
|
EROS-PIA02907_modest.jpgA strange drawing made by lights and shadows...77 visiteEros' irregular shape creates interesting and beautiful scenes where the Sun shines obliquely on the surface. In the absence of an atmosphere, and hence no secondary illumination reflecting from atmospheric molecules, shade appears nearly as black as space. This image, taken from the NEAR Shoemaker spacecraft on May 2, 2000, from an orbital altitude of 50 kilometers (31 miles), shows one of the more telling and yet comical combinations of light and shadow. The entire scene is about 1.8 kilometers (1.1 miles) across. High spots near the edges of shadows, like the 35-meter (115-foot) diameter boulder just below the center of the frame, seem almost to "float" above the surface. With a little imagination, the shadow dominating the right side of the frame could be seen as a small, long-eared terrier bending over to sniff his dinner!
|
|
EROS-PIA02927.jpgEros' Boulders132 visiteNEAR Shoemaker images have shown many large boulders on Eros' surface, but seldom are the boulders as big and as close as the ones in this image taken on June 20, 2000, from an altitude of 51 Km. Nestled within the 700-meter (2300-foot) diameter crater at the center of the picture are four particularly large rocks whose tops protrude out from the shadowed crater interior and into sunlight. The center boulder, the largest, is about 100 meters (330 feet) across. The whole scene is approximately 1.9 Km across.
|
|
| 288 immagini su 24 pagina(e) |
 |
|
|
|
|
13 | |
|
|
|
|
