433-Eros: Pictures, Facts and Legends
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20000307.jpgLooking at "The Saddle" (natural colors; credits: Lunexit)53 visiteThis image of the interior of Eros' "Saddle Area", taken at a range of 204 Km (about 127 miles), displays a paucity of craters compared to the surface on the right hand side of the image. The Saddle displays many interesting structural features. Visible on the left wall are a series of closely spaced grooves that follow the terrain downslope. Opposite, on the upper right wall, trending towards the back of the saddle is a prominent ridge. Boulders are visible throughout this image.
Features as small as 20 meters (65 feet) are discernable.
(Image 0127521108)MareKromium
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20000309.jpgOblique view of the "Large Crater" (natural colors; credits: Lunexit)53 visiteThis image, showing an oblique view of Eros' "Large (central) Crater", was taken at a resolution of about 20 meters (65 feet) per pixel. The brightness or albedo patterns on the walls of this crater are clearly visible, with the brighter materials near the tops of the walls and darker materials on the lower walls. Boulders are seen inside this crater and the smaller nearby craters. The higher density of craters to the left of the large crater implies that this region is older than the smoother area seen associated with the Saddle Region on the opposite side of the asteroid.
(Image 0127591846)MareKromium
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20000314-PCF-LXTT-IPF.jpgThe "Saddle Region" (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)102 visiteCaption NASA:"This image mosaic, showing Eros' Saddle and a shadowed feature to its left, was taken on March 3, 2000 from a distance of 204 Km (about 127 miles). In this picture features as small as 20 meters (65 feet) across are visible. This is the best view to date of this area. The Sun is coming from the North-East illuminating a shadowed feature that consists of 3 large craters situated adjacent to each other. The two largest are each about 4-5 Km (2-3 miles) across.
Because the Sun is very low with respect to these craters, even small topographic features cast long shadows, making them easier to see. As a result, several boulders on the crater walls can be distinguished, ranging from about 50 to 100 meters in diameter. The Saddle (on the right of the mosaic) is relatively smooth with few impact craters, and has several grooves running across it. At the top of the saddle are several curved grooves that are brighter than the surrounding surface. Unusual brightness patterns are also visible in the crater at the top left of the mosaic. The walls of the crater appear to be more reflective and its floor less reflective than nearby parts of the asteroid.
(Mosaic of images 0127504836, 0127504898, 0127505146, 0127505208,0127505394, 0127505456)MareKromium
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20000320.jpgThe North Polar Region of 433-Eros (natural colors; credits: Lunexit)53 visiteOn March 11, 2000, this image of Eros' North Polar Region was acquired by the imager on the NEAR Shoemaker Spacecraft, from a range of 206 Km (127 miles).
The area shown in the image is 10 Km (6,2 miles) across. Most of the North Polar Region is heavily cratered but the region to the left (part of the "Saddle") has a lower crater density, indicating that the surface has been modified since it first formed.
Eros' rotational axis lies nearly parallel to its orbital plane, much as with the planet Uranus, giving the asteroid exaggerated "seasons".
Now, it is Northern Summer and the North Pole is in continuous sunlight. The Sun will set there this June, at Eros' equivalent of Earth's Autumnal Equinox. At that time, Eros' South Pole will begin 12 months of continuous illumination while the North Pole shall remain in darkness.
(Image 0128166012)MareKromium
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20000322.jpg433-Eros in HR (True Colors; credits: NASA)53 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 1748 Km (about 1083 miles), 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 (about 175 miles) and shows much smaller details only 27 meters (89 feet) across.
The higher spatial resolution (by a factor of 6) brings out a whole class of surface details that were either invisible or at the margin of visibility in the earlier images. For example, the bright material on the wall of the large crater in the inset image is barely evident in the lower-resolution image at left, but by virtue of its limited spatial coverage the inset image lacks information on the crater's regional geologic setting. NEAR Shoemaker's imaging strategy makes use of both types of images, with lower-resolution images providing "context" for higher-resolution images that bring specific features into sharper focus.
(Product of images 0125748893, 0125748895, 0125748897, 0127229466, 0127229468, 0127229470)
MareKromium
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20000405.jpgOld Craters (natural colors; credits: Lunexit)53 visiteEros' many craters have a range of ages dating back to the last time the asteroid's surface was "wiped clean" by geologic processes. This NEAR Shoemaker image of the tip of the asteroid, taken March 6, 2000, from a range of 201 Km (about 125 miles), shows craters with a variety of shapes and sizes.
When small craters first form, they typically have sharp rims and round floors. As they age, progressively smaller craters are superimposed, rounding the rims and pitting the walls and floors until the original underlying crater becomes almost unrecognizable.
(Image 0127738155)MareKromium
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20000410.jpgDifferent Lights, Different Visions53 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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20000411.jpgEros' North Polar Region (natural colors; credits: Lunexit)53 visiteFor much of the past five weeks, imaging activities on the NEAR Shoemaker Spacecraft have focused on the high Northern Latitudes of Eros.
The point at which the Sun is directly overhead - known as the "subsolar point" - has been steadily moving from Eros' Northern Regions toward the Equator as the Asteroid's seasons progress.
As this happens, the Northern Hemisphere is illuminated less and less, and previously dark Southern Latitudes progressively come into view.
In this image, taken March 19, 2000, from a range of 205 Km (approx. 127 miles), the asteroid's North Pole is in the upper right of the frame. The whole scene is 7,4 Km (4,6 miles) across.
(Image 0128883708)MareKromium
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20000418.jpgUp-close and personal (natural colors; credits: Lunexit)53 visiteSince April 11, 2000, the NEAR Shoemaker Spacecraft has orbited Eros at an altitude of about 100 Km (approx. 62 miles) from the Asteroid's Center. Images acquired from this orbit will be used to make a HR map of the illuminated portion of the Asteroid. Each spot on the surface will be imaged under a variety of lighting and viewing conditions to bring out different features.
In this image, taken April 17, 2000, from a height of 101 Km (approx. 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.
(Image 0131288775)MareKromium
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20000428.jpgGroovy!... (natural colors; credits: Lunexit)53 visiteNEAR Shoemaker returns images that reveal not only what makes Eros distinctive, but also what it shares with other asteroids. This image, taken April 8, 2000, from an orbital height of 210 Km (about 131 miles), shows several of the linear troughs or "grooves" that mark the Asteroid's surface.
The largest one in this image, just to the right of the shadowed crater in the lower central part of the frame, is nearly 200 meters (656 feet) across. Grooves are also found on other asteroids and small asteroid-like moons, especially the Martian moon Phobos. They are thought to form when regolith - the loose surface material thrown out of impact craters - drains into subsurface cracks.
(Image 0130614349)MareKromium
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20000522.jpg"Alien Antenna" or just an ordinary-looking Outcrop? (natural colors; credits: Lunexit)65 visitenessun commentoMareKromium
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20000608.jpgThe "Saddle" (Extremely Saturated True Colors; credits: Lunar Explorer Italia)54 visitenessun commentoMareKromium
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