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Flying Over Asteroid Eros
| Title |
Flying Over Asteroid Eros |
| Explanation |
What would it look like to fly over an asteroid? Spacecraft NEAR Shoemaker [ http://near.jhuapl.edu/NEAR/Voyage/ ] in orbit around asteroid 433 Eros [ http://near.jhuapl.edu/NEAR/eros/sum.html ] found out earlier this month when it recorded its first fly-over sequence. The saddle region [ http://antwrp.gsfc.nasa.gov/apod/ap000214.html ] of the Sun-orbiting space-mountain appears to zip past the camera in this condensed hour-long time-lapse sequence [ http://near.jhuapl.edu/NEAR/iod/20000323/ ]. The spacecraft was orbiting about 200 kilometers above the asteroid [ http://www.seds.org/nineplanets/nineplanets/asteroids.html ]. Movies such as this are scientifically useful [ http://antwrp.gsfc.nasa.gov/apod/ap991108.html ] for discerning between regions that are naturally dark and regions that have their brightness dominated by shadows. The week before, a bright X-ray burst [ http://antwrp.gsfc.nasa.gov/apod/ap000327.html http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1999A%26A...347..684G ] from the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap981221.html ] allowed NEAR's X-ray spectrometer [ http://near.jhuapl.edu/NEAR/instruments/ ] to detect [ http://www.jhuapl.edu/public/pr/000313.htm ] the presence of several elements [ http://pearl1.lanl.gov/periodic/ ] on Eros' surface by their X-ray fluorescent [ http://www.scimedia.com/chem-ed/spec/atomic/afs.htm ] signatures. |
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Eros At Sunset
| Title |
Eros At Sunset |
| Explanation |
Gleaming in the rays of the setting sun, boulders litter the rugged surface of asteroid 433 Eros [ http://near.jhuapl.edu/eros/ ]. The brightest boulder, at the edge of the large, shadowy crater near this picture's bottom center, is about 30 meters (100 feet) across. In orbit around Eros since February 2000, the NEAR Shoemaker [ http://near.jhuapl.edu/NEAR/ ] spacecraft's camera recorded the dramatic view [ http://near.jhuapl.edu/NEAR/iod/20000821/index.html ] earlier this month from an altitude of about 50 kilometers. Eros itself orbits [ http://www.fwkc.com/encyclopedia/low/articles/o/ o018000416f.html ] the Sun with a perihelion [ http://imagine.gsfc.nasa.gov/docs/ dictionary.html#perihelion ] of 1.13 Astronomical Units [ http://imagine.gsfc.nasa.gov/docs/ask_astro/ answers/980122b.html ] (AU) and aphelion [ http://imagine.gsfc.nasa.gov/docs/ dictionary.html#aphelion ] of 1.78 AU. Part of a class of near-Earth asteroids [ http://neo.jpl.nasa.gov/neo.html ], it spends much of its time between the orbits of Mars (at 1.5 AU) and Earth (at 1 AU) ... but it wasn't always that way. Eros and other near-Earth asteroids [ http://neo.planetary.org/ABCsOfNEOs/index.html ] originally orbited in the main asteroid belt [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/ asteroids.html ], between Jupiter [ http://galileo.jpl.nasa.gov/jupiter/jupiter.html ] and Mars [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/ marsfact.html ]. Over time, the gravitational influence of Jupiter and other planets perturbed their orbits sending them on trajectories closer [ http://antwrp.gsfc.nasa.gov/apod/ap000226.html ] to Earth. |
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Stereo Eros
| Title |
Stereo Eros |
| Explanation |
Get out your red/blue glasses [ http://photojournal.jpl.nasa.gov/Help/VendorList.html#Glasses ] and float next to asteroid 433 Eros [ http://neo.jpl.nasa.gov/cgi-bin/db?name=433 ], now over 220 million kilometers away! Orbiting the Sun once every 1.8 earth-years, asteroid Eros is [ http://near.jhuapl.edu/eros/history/eros_useful.html ] a diminutive 40 x 14 x 14 kilometer world of undulating horizons, craters, boulders [ http://antwrp.gsfc.nasa.gov/apod/ap000721.html ] and valleys. Its unsettling scale and bizarre shape are emphasized in this picture [ http://photojournal.jpl.nasa.gov/catalog/PIA02471 ] - a mosaic of images from the NEAR Shoemaker [ http://photojournal.jpl.nasa.gov/target/ Other?subselect=Spacecraft%3ANEAR+Shoemaker%3A ] spacecraft processed to yield a stereo anaglyphic [ http://faxmentis.org/html/ana-howto.html ] view. Along with dramatic [ http://en.wikipedia.org/wiki/Chiaroscuro#Gallery ] chiaroscuro [ http://studiochalkboard.evansville.edu/s-chiaro.html ], NEAR's 3-D imaging provided important measurements of the asteroid's landforms and structures, and clues to the origin of this city-sized chunk of solar system [ http://space.jpl.nasa.gov/ ]. The smallest features visible here are about 30 meters across. After spending a year in orbit around Eros, the historic Near Shoemaker spacecraft made the first ever landing on an asteroid's surface [ http://antwrp.gsfc.nasa.gov/apod/ap010824.html ] February 12, 2001. |
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Survivor: NEAR Shoemaker On
…
| Title |
Survivor: NEAR Shoemaker On Asteroid Eros |
| Explanation |
Not part of a television game series, the NEAR Shoemaker spacecraft survived [ http://www.jhuapl.edu/public/pr/010228.htm ] its unprecedented landing on an asteroid [ http://www.nineplanets.org/asteroids.html ] last month. As suggested in the illustration inset above [ http://near.jhuapl.edu/NEAR/iod/20010209/index.html ], the car-sized probe likely rests gently on the tips of its solar panels having touched down under the influence of asteroid Eros' feeble gravity. Fortunately, the spacecraft's solar panels were bathed in sunlight and able to power NEAR's gamma-ray spectrometer [ http://near.jhuapl.edu/NEAR/instruments/ XGRS/index.html ]. Perched on the asteroid, this instrument can determine the composition of Eros to a depth of about 10 centimeters with unanticipated accuracy by measuring the gamma-ray signatures [ http://science.msfc.nasa.gov/headlines/y2001/ast27feb_2.htm ] of the atomic nuclei present. The data returned [ http://near.jhuapl.edu/NEAR/iod/20010301/ ] from the surface of Eros are plotted above and show clearly features corresponding to Iron, Oxygen, Silicon, and Potassium in the asteroid's regolith [ http://antwrp.gsfc.nasa.gov/apod/ap000829.html ]. Also briefly operating on Eros, NEAR's magnetometer [ http://near.jhuapl.edu/NEAR/instruments/MAG/index.html ] has indicated that no surface magnetic field [ http://www-spof.gsfc.nasa.gov/Education/wmfield.html ] is discernible. Now turned off [ http://near.jhuapl.edu/NEAR/Reports/WeeklyStatus/ 2001-03-02.txt ], NEAR Shoemaker could remain preserved in its present location, the vicinity of the huge, saddle-shaped feature dubbed Himeros [ http://antwrp.gsfc.nasa.gov/apod/ap001026.html ], for billions of years. But, as the asteroid orbits [ http://science.nasa.gov/headlines/y2000/ ast21jun_1_ada.htm ], the spacecraft's solar panels will be repeatedly turned toward the Sun ... offering the possibility of reawakening this survivor [ http://antwrp.gsfc.nasa.gov/apod/ap010213.html ]. |
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Stereo Eros
| Title |
Stereo Eros |
| Explanation |
Get out your red/blue glasses [ http://mpfwww.jpl.nasa.gov/MPF/mpf/glasses.html ] and float next to asteroid 433 Eros [ http://neo.jpl.nasa.gov/cgi-bin/db?name=433 ], 170 million kilometers away! Orbiting the Sun once every 1.8 earth-years, asteroid Eros is [ http://near.jhuapl.edu/eros/history/eros_useful.html ] a diminutive 40 x 14 x 14 kilometer world of undulating horizons, craters, boulders [ http://antwrp.gsfc.nasa.gov/apod/ap000721.html ] and valleys. Its unsettling scale and bizarre shape are emphasized in this picture [ http://near.jhuapl.edu/NEAR/iod/20000218/index.html ] - a mosaic of images from the NEAR Shoemaker spacecraft [ http://near.jhuapl.edu/NEAR/news/flash/02dec12_1.html ] processed to yield a stereo anaglyphic [ http://near.jhuapl.edu/NEAR/3_d.html ] view. Along with dramatic [ http://www.artofcolour.com/chiaroscuro/chiaroscuro-image-files/ st-matthew.jpg ] chiaroscuro [ http://www2.evansville.edu/studiochalkboard/ s-chiaro.html ], NEAR's 3-D imaging provided important measurements of the asteroid's landforms and structures, and clues to the origin [ http://near.jhuapl.edu/NEAR/Voyage/1.html ] of this city-sized chunk of solar system [ http://space.jpl.nasa.gov/ ]. The smallest features visible here are about 30 meters across. After spending a year in orbit around Eros, the historic Near Shoemaker spacecraft made the first ever landing on an asteroid's surface [ http://antwrp.gsfc.nasa.gov/apod/ap010824.html ] February 12, 2001. |
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NEAR Shoemaker's Path
| Title |
NEAR Shoemaker's Path |
| Description |
This plot shows NEAR Shoemaker's projected path from orbit to the surface of Eros on Feb. 12. Viewed from the sun, Eros is moving in a clockwise direction as it spins on its axis, while the spacecraft moves counterclockwise in a circular orbit 35 kilometers (22 miles) from the asteroid's center. The pair will be about 316 million kilometers (196 million miles) from Earth. NEAR Shoemaker will de-orbit with a short engine burn at 10:31 a.m. EST, about 4 1/2 hours before it's scheduled to reach the surface. The final leg of the controlled descent begins with the spacecraft about 5 kilometers (3 miles) above Eros, it will then execute an unprecedented series of four engine burns designed to slow its descent from about 20 mph to about 5 mph. NEAR Shoemaker is expected to touch down in an area bordering Himeros, the asteroid's distinctive saddle-shaped depression, after providing the highest-resolution images ever taken of Eros' boulder-strewn, cratered terrain. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
| Date |
02.08.2001 |
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Two Very Different Asteroids
| Title |
Two Very Different Asteroids |
| Description |
The NEAR Shoemaker spacecraft has scored two important firsts in the exploration of asteroids: it's the first to orbit an asteroid, Eros, and the first to encounter a denizen of the outer reaches of the asteroid belt, the C-type asteroid Mathilde. In a scheme that reflects how they have historically been a topic for astronomy, not geology, asteroids are classified into groups based on their colors as observed through telescopes. The two major classes of asteroids are called S-types and C-types. S-types, whose colors are consistent with "stony" or rocky compositions, prevail among asteroids that orbit closer to the Sun than the mid-point of the asteroid belt. Eros and the two asteroids encountered briefly by the Galileo spacecraft on its way to Jupiter -- Gaspra and Ida -- are all S-types. C-types like Mathilde have a dark gray color consistent with a "carbonaceous" composition, rich in carbon compounds and other dark materials. They prevail in the outer part of the asteroid belt. In this montage, Mathilde (at left) and Eros (at right) are shown at the same scale, as they were imaged by NEAR Shoemaker from about 1,800 kilometers (1,116 miles) on June 27, 1997, and February 12, 2000, respectively. Mathilde is 56 kilometers (35 miles) across, and Eros is 33 kilometers (21 miles) long and 13 kilometers (8 miles) wide. However, Mathilde's brightness is greatly exaggerated for viewing purposes -- it's actually six times darker than Eros, with about the same reflectivity as soot! Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
| Date |
03.30.2000 |
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Eros' Bland Butterscotch Col
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PIA02475
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros' Bland Butterscotch Colors |
| Original Caption Released with Image |
These color images of Eros was acquired by NEAR on February 12, 2000, at a range of 1800 kilometers (1100 miles) during the final approach imaging sequence prior to orbit insertion. A five and one-half hour long sequence of images covering visible and infrared wavelengths was taken at that time, to provide a global overview of the color and spectral properties of the asteroid. The images show approximately the color that Eros would appear to the unaided human eye. Eros' subtle butterscotch hue at visible wavelengths is nearly uniform across the surface. Two days after these images were taken, mapping by NEAR's infrared spectrometer showed that Eros exhibits a great deal more variety at longer wavelengths. These variations could be due to differences in texture or composition of the surface. Both NEAR's multispectral imager and infrared spectrometer will be used extensively during the month of March to map Eros' color and spectral properties from an altitude of 200 kilometers (120 miles). The images to be returned will show details as small as 20 meters (68 feet) across, providing a new perspective on the asteroid's many fascinating landforms discovered so far by NEAR. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros' Global Morphology
PIA02473
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros' Global Morphology |
| Original Caption Released with Image |
On 12 February, 2000, the NEAR spacecraft obtained a sequence of 780 images of Eros from a range of about 1800 km (1100 miles). This sequence covered one complete revolution of the asteroid at 0.5 degree intervals. In these views of opposite hemispheres of the asteroid, groups of images slightly apart in time were digitally processed to bring out local details. The processed data showing Eros from slightly different perspectives can then be combined as anaglyphs or stereo pairs. The processing of the data highlights the topography of small-scale features, but makes the gross shape of the asteroid appear flattened. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Inside Eros' Giant Gouge
PIA02469
Sol (our sun)
Multi-Spectral Imager
| Title |
Inside Eros' Giant Gouge |
| Original Caption Released with Image |
This picture was taken from NEAR on February 15, 2000, while the spacecraft was passing directly over the large gouge that creates Eros's characteristic peanut shape. It is a mosaic of individual images showing features as small as 120 feet (35 meters) across. Although most of the asteroid is in shadow, we are able to see inside the gouge. Many narrow parallel troughs closely follow the shape of the gouge. Although they appear curvilinear from this view, they are most likely oriented parallel to the length of the asteroid. The strong lighting contrast along the terminator (the line separating day from night on Eros) makes it easy to see that most of the surface is saturated with impact craters. Inside the gouge, however, only smaller craters are present, indicating that the area within the gouge is younger than the surface along the terminator. This implies that the event that caused the gouge must have happened more recently than the formation of the rest of the surface of Eros. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros: The first look from or
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PIA02465
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros: The first look from orbit |
| Original Caption Released with Image |
In the first hours after NEAR's insertion into Eros orbit (February 14, 2000), the spacecraft's camera took these images from a range of 210 miles (330 km) above the surface. The many craters visible serve as landmarks for navigating the spacecraft. Mission operators observe such features from different angles, and use triangulation to calculate NEAR's position relative to the surface of Eros. The changes in position over time help to plot NEAR's course in orbit. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros Image Mosaic, looking n
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PIA02472
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros Image Mosaic, looking north |
| Original Caption Released with Image |
This image mosaic of Eros was taken by the NEAR spacecraft on Feb. 18, 2000 from a range of 224 miles (361 kilometers). The smallest detail visible on the surface is about 115 feet (35 meters) across. At the time the spacecraft was over the shadowed southern hemisphere, looking north at a crescent Eros. Although this view of Eros is similar to others that have been returned, the coverage at different illumination and viewing geometries provides important information on the shapes of landforms. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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NEAR's first whole-Eros mosa
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PIA02467
Sol (our sun)
Multi-Spectral Imager
| Title |
NEAR's first whole-Eros mosaic from orbit |
| Original Caption Released with Image |
This picture of Eros, the first of an asteroid taken from an orbiting spacecraft, is a mosaic of four images obtained by NEAR on February 14, 2000, immediately after the spacecraft's insertion into orbit. We are looking down over the north pole of Eros at one of the largest craters on the surface, which measures 4 miles (6 kilometers) across. Inside the crater walls are subtle variations in brightness that hint at some layering of the rock in which the crater formed. Narrow grooves that run parallel to the long axis of Eros cut through the southeastern part of the crater rim. A house-sized boulder is present near the floor of the crater, it appears to have rolled down the bowl-shaped crater wall. A large number of boulders is also present on other parts of the asteroid's surface. The surface of the asteroid is heavily cratered, indicating that Eros is relatively old. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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NEAR Approach to Eros - 12 p
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PIA02463
Sol (our sun)
Multi-Spectral Imager
| Title |
NEAR Approach to Eros - 12 panel rotation sequence |
| Original Caption Released with Image |
On February 12, two days before NEAR's insertion into orbit around Eros, during a five-hour time span the spacecraft's Multispectral Imager recorded these pictures of the asteroid spinning on its axis. This view, looking down toward the rocky body's north pole, is generally similar to sequences taken on February 6, 10, and 11. But the spacecraft was much closer to Eros (about 1,800 kilometers or a little over 1,100 miles), so the pictures are much sharper. Features as small as a 590 feet (180 meters) wide can be seen. The most prominent, sharp-rimmed impact crater is on the opposite side of Eros from a huge, hollowed-out gouge, which may also have been caused by an impact. Between these features, and towards the ends of the "fat banana" shape of Eros, the asteroid's surface is covered with smaller craters. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Mosaic of Mathilde
PIA02477
Sol (our sun)
Multi-Spectral Imager
| Title |
Mosaic of Mathilde |
| Original Caption Released with Image |
This image mosaic of asteroid 253 Mathilde is constructed from four images acquired by the NEAR spacecraft on June 27, 1997. This was taken from a distance of 2,400 km (1,500 miles). Sunlight is coming from the upper right. The part of the asteroid shown is about 59 by 47 km (36 by 29 miles) across. Details as small as 380 meters (1,250 feet) can be discerned. The surface exhibits many large craters, including the deeply shadowed one at the center, which is estimated to be more than 10 kilometers (6 miles) deep. The shadowed, wedge-shaped feature at the lower right is another large crater viewed obliquely. The angular shape of the upper left limb of the asteroid results from the rim of a third large crater viewed edge-on. The bright mountainous feature at the far left may be the rim of a fourth large crater emerging from the shadow. The angular shape is believed to result from a violent history of impacts. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Abundance of Very Large Impa
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PIA02478
Sol (our sun)
Multi-Spectral Imager
| Title |
Abundance of Very Large Impact Craters on Mathilde |
| Original Caption Released with Image |
This view of 253 Mathilde, taken from a distance of about 1,200 km (748 miles), was acquired shortly after the NEAR spacecraft's closest approach to the asteroid. In this image, the asteroid has been rotated so that the illumination appears to come from the upper left. This portion of Mathilde shows numerous impact craters, ranging from over 30 km to less than 0.5 km (18.. 0.3 miles) in diameter. Raised crater rims suggest that some of the material ejected from these craters traveled only short distances before falling back to the surface, straight sections of some crater rims indicate the influence of large faults or fractures on crater formation. The number of craters as a function of size, and the number of each size within the visible area, are similar to values seen on asteroid 243 Ida, viewed by the Galileo spacecraft in 1993. A major difference between Ida and Mathilde appears to be the abundance of very large craters: Mathilde has at least 5 craters larger than 20 km in diameter on the roughly 60% of the body viewed during the encounter. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Over Eros' Horizon
PIA02468
Sol (our sun)
Multi-Spectral Imager
| Title |
Over Eros' Horizon |
| Original Caption Released with Image |
This incredible picture of Eros, taken on February 14, 2000, shows the view looking from one end of the asteroid across the gouge on its underside and toward the opposite end. In this mosaic, constructed from two images taken after the NEAR spacecraft was inserted into orbit, features as small as 120 feet (35 meters) across can be seen. House-sized boulders are present in several places, one lies on the edge of the giant crater separating the two ends of the asteroid. A bright patch is visible on the asteroid in the top left-hand part of this image, and shallow troughs can be see just below this patch. The troughs run parallel to the asteroid's long dimension. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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NEAR Historic First Image fr
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PIA02464
Sol (our sun)
Multi-Spectral Imager
| Title |
NEAR Historic First Image from Eros Orbit |
| Original Caption Released with Image |
February 14, 2000, at 10:33 AM EST the NEAR spacecraft was successfully inserted into orbit around 433 Eros, becoming the first artificial satellite of an asteroid. Just over an hour later, NEAR pointed its camera at the asteroid and took this picture from a range of 210 miles (330 km) above the surface. Mission navigators and operators will use this image and others to be taken later to triangulate on landmarks on the asteroid's surface, precisely measuring position of the spacecraft to plot NEAR's course. Features as small as a 100 feet (30 meters) across can be seen. This view shows the 3-mile (5-kilometer) impact crater which the spacecraft has spied for over a week during its approach. The two smaller craters superimposed on its rim are each about 1.2 miles (2 kilometers) across. An enormous boulder a full 170 feet (50 meters) in size sits on the large crater's floor. Other key features of the surface are shallow subsurface layering exposed near the tops of crater walls, and shallow grooves crossing the surface and cutting the crater's rim. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
|
Eros in color
PIA02470
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros in color |
| Original Caption Released with Image |
This color image of Eros was acquired by NEAR's multispectral imager on February 12, 2000, at a range of 1100 miles (1800 kilometers). It is part of the final approach imaging sequence prior to orbit insertion and is intended to map the color properties of Eros across all of the illuminated surface. The image shows approximately the color that Eros would appear to the unaided human eye. Its subtle butterscotch hue is typical of a wide variety of minerals thought to be the major components of asteroids like Eros. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros' Eastern and Western He
…
PIA02474
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros' Eastern and Western Hemispheres |
| Original Caption Released with Image |
On February 23, 2000, the NEAR spacecraft obtained a sequence of image mosaics showing Eros' surface as the asteroid rotated under the spacecraft. At that time the range to the surface was approximately 355 kilometers (220 miles). These two mosaics, part of that sequence, show the stark beauty of the two opposite hemispheres. The smallest detail visible is 35 meters (120 feet) across. The top mosaic shows wavy brightness banding exposed in the interior walls of the saddle. In the bottom mosaic, similar banding is visible in one of the craters near the limb at left. To the right, the angle of the illumination accentuates the quasi-linear troughs near the terminator. Successful firing of NEAR's thrusters yesterday, February 24, placed the spacecraft on course for insertion into the next lower orbit, at a 200 kilometer (120 mile) altitude. Images from that orbit, commencing in early March, will have nearly twice the spatial resolution of data returned so far. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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NEAR Road to Eros
PIA02462
Sol (our sun)
Multi-Spectral Imager
| Title |
NEAR Road to Eros |
| Original Caption Released with Image |
This montage shows a selection of images of the asteroid 433 Eros that were acquired from the NEAR spacecraft over three weeks from January 22 through February 12, 2000, as the spacecraft's distance from its target shrank from 18,000 to 1260 miles (29,000 to 2025 km). As the spacecraft closed in on its target, the resolution of the images increased from 1.7 to 0.12 miles (2.8 to 0.19 km) per pixel. At 20x8x8 miles in size (33x13x13 kilometers), Eros is the second largest near-Earth asteroid and spins on its axis once every 5 hours, 16 minutes. During the early stages of NEAR's approach, Eros appeared as a small blob only a few pixels across. The apparent size of Eros and the resolution of the pictures increased continuously, at first only slowly and later dramatically day by day until, on February 9, the level of detail visible exceeded that during NEAR's first flyby of Eros on December 23, 1998. In the last images shown here, details of Eros's surface have become visible. Heavy cratering has pockmarked the irregular asteroid's surface. One side is dominated by a scallop-rimmed gouge, and the opposite side by a conspicuous, raised-rimmed crater. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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First NEAR image of Mathilde
PIA02476
Sol (our sun)
Multi-Spectral Imager
| Title |
First NEAR image of Mathilde |
| Original Caption Released with Image |
This first image of asteroid 253 Mathilde, returned by the NEAR spacecraft just before 10:00 AM EDT on June 27, 1997, was taken from a distance of 1800 kilometers (1120 miles). Sunlight is coming from the upper right. The part of the asteroid shown is about 59 kilometers (36 miles) across, and the scale is approximately 230 meters (780 feet) per pixel. The surface is heavily cratered, and the large shadowed area on the left may be a single impact gouge well over 10 kilometers (6 miles) deep. The angular form of the edge of the shadowed area suggests that large impacts may have spalled large pieces off the asteroid. This asteroid is very dark, reflecting only about 4% of the light falling on it, but was imaged easily by the sensitive NEAR multispectral camera Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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NEAR Approach to Eros
PIA02461
Sol (our sun)
Multi-Spectral Imager
| Title |
NEAR Approach to Eros |
| Original Caption Released with Image |
Approximately one day after its first rendezvous burn, NEAR imaged Eros every 15 degrees of rotation over a period of about 5.8 hrs. At this time the distance between the asteroid and spacecraft was approximately 4638 miles (7730 km). These images taken during approach to the asteroid are used by mission navigators and operators to make the proper corrections in the spacecraft's trajectory during the critical burns coming up on Feb. 8 and Feb. 14. As an added bonus, these "OpNav" (optical navigation) images provide an increasingly detailed view of surface features on the asteroid. The resolution has increased to about 0.5 miles (0.8 km) per pixel, revealing the presence of 3 small craters on the surface. Over the next 10 days our view of the surface will become increasingly detailed and will allow for nearly global low resolution mapping of the asteroid before NEAR goes into orbit about Eros on Valentine's Day, Feb. 14. Once in orbit, NEAR's suite of scientific instruments will allow for global mapping of the asteroid at very high resolution. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros details enhanced by com
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PIA02466
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros details enhanced by computer processing |
| Original Caption Released with Image |
The NEAR camera's ability to show details of Eros's surface is limited by the spacecraft's distance from the asteroid. That is, the closer the spacecraft is to the surface, the more that details are visible. However mission scientists regularly use computer processing to squeeze an extra measure of information from returned data. In a technique known as "superresolution", many images of the same scene acquired at very, very slightly different camera pointing are carefully overlain and processed to bright out details even smaller than would normally be visible. In this rendition constructed out of 20 image frames acquired Feb. 12, 2000, the images have first been enhanced ("high-pass filtered") to accentuate small-scale details. Superresolution was then used to bring out features below the normal ability of the camera to resolve. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros in stereo
PIA02471
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros in stereo |
| Original Caption Released with Image |
Stereo imaging will be an important tool on NEAR for geologic analysis of Eros, because it provides three-dimensional information on the asteroid's landforms and structures. This anaglyph can be viewed using red-blue glasses to show Eros in stereo. It was constructed from images taken on February 14 and 15 that showed the same part of Eros from two slightly different viewing perspectives. The smallest feature visible is 100 feet (30 meters) across. For this image the spacecraft position was not optimum for stereo, but it will improve over the next few days allowing better 3-D views. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Two Views of Mathilde
PIA02479
Sol (our sun)
Multi-Spectral Imager
| Title |
Two Views of Mathilde |
| Original Caption Released with Image |
Two different views of asteroid 253 Mathilde were obtained by the NEAR spacecraft on June 27, 1997. The image at left was obtained as the spacecraft approached Mathilde with its camera pointed near the direction of the Sun, only a few of the prominent ridges on Mathilde are illuminated. The visible area at left is 29 km (18 miles) high, and the phase angle (the angle from Sun-Mathilde spacecraft) is 136°. As the spacecraft receded from Mathilde, it observed the asteroid (about 60 km or 38 miles across) almost fully lit by the Sun at a phase angle of 43° (right image). Mathilde's irregular shape results from a long history of severe collisions with smaller asteroids. The largest visible crater is 30 km (19 miles) in diameter. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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NEAR: From Planning to Data
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PIA02489
Sol (our sun)
Near Infra-Red Spectrometer
| Title |
NEAR: From Planning to Data Analysis |
| Original Caption Released with Image |
Planning and acquiring observations from NEAR's Near-Infrared Spectrometer (NIS) is a complex process that requires a detailed understanding of the strange shape and the rotational state of Eros. On February 13-14, 2000, just before insertion into Eros orbit, NEAR passed between Eros and the Sun. This geometry is called a low phase angle. It is optimum for spectroscopic observations, so at that time NIS obtained some of its most valuable data. To plan these activities in the preceding months, the NEAR science team developed a series of global NIS observation sequences like the one depicted in the left image. Here, NIS was instructed to scan its mirror back and forth across Eros while the spacecraft did a slow slew from top to bottom. The image shows the predicted coverage as viewed from directly over the north pole of a computerized "shape model" of Eros. Many such observation sequences were performed flawlessly on the spacecraft during the "low phase-angle flyby," and the highest-quality spectra were combined to show the resulting NIS coverage of Eros in the map on the right. The green and red regions show areas at high northern latitudes with the best coverage by NIS. Analysis of the NIS spectra is providing clues about the mineralogy and composition of Eros, and perhaps its early history and evolution. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Impact at High Noon
PIA02499
Sol (our sun)
Multi-Spectral Imager
| Title |
Impact at High Noon |
| Original Caption Released with Image |
For people who live in mountain valleys, daylight can be a short-lived experience. Mountains to the east make the Sun rise later in the morning, while mountains to the west make the Sun set earlier in the evening. The brevity of daytime in a valley is accentuated during the shortened days of winter. The floor of the 5.5-kilometer (3.4-mile) diameter impact crater that dominates one face of Eros experiences the ultimate in short daylight hours. Three factors conspire to make this true. Firstly, Eros rotates rapidly, once every 5.27 hours. Secondly, the crater's 0.9-kilometer (0.56-mile) high walls tend to block direct sunlight from the floor, even while the outside of the crater is illuminated. Thirdly, during the current season on Eros, the Sun never makes it high in the sky in this location. This NEAR Shoemaker image, taken April 1, 2000, from a range of 209 kilometers (130 miles), caught the crater near local noon with the Sun highest in the sky. On that day, a hardy astronaut standing at the bottom of the crater would have experienced 1 hour and 45 minutes of daylight. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Interesting Structural Featu
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PIA02482
Sol (our sun)
Multi-Spectral Imager
| Title |
Interesting Structural Features on Eros |
| Original Caption Released with Image |
This image of the interior of Eros' saddle area, taken at a range of 204 km (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 in this image. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Large Crater on Eros
PIA02481
Sol (our sun)
Multi-Spectral Imager
| Title |
Large Crater on Eros |
| Original Caption Released with Image |
This image mosaic of the large crater at Eros' center was taken on March 3, 2000 during an optical navigation imaging sequence from a range of 127 miles (204 kilometers). This same area was imaged following orbit insertion at a range of approximately 210 miles (330 kilometers) on February 14th. This picture resolves features as small as 65 feet (20 meters) across compared to the resolution of 100 feet (30 meters) in the earlier image. The shadow cast by the boulder near the floor of the crater is now visible. The walls of the crater display some distinctive variations in their albedo or reflectivity. The upper part of the walls tend to be bright, while the lower portions of the walls and the crater floor show patches of darker or less reflective materials. These albedo patterns are also visible on other crater walls. To the right of the large crater, two sets of closely spaced orthogonal grooves are visible. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros Surface Morphology
PIA02491
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros Surface Morphology |
| Original Caption Released with Image |
On March 10, 2000, this image of Eros was acquired by the imager on the NEAR Shoemaker spacecraft, from a range of 206 kilometers (127 miles). The area shown in the image is 10 kilometers (6.2 miles) across, and the smallest detail visible is 20 meters (65 feet) across. Here, the spacecraft was over the shaded interior of the "saddle," looking over the north polar region to the limb. The shadowing at the upper right is due to oblique lighting. The narrowness of the illuminated part of Eros in the center of the frame results from viewing the narrow "waist" of Eros' irregular peanut-like shape. This image is from one of a large number of imaging sequences acquired during the first of two "200-kilometer" (124-mile) orbits. The second 200-kilometer orbit, in autumn 2000, will provide similar views of southern latitudes. The purpose of many of the sequences in this orbit is to view the northern and equatorial latitudes of the asteroid under conditions similar to those at the time of this image, looking straight down on a part of the surface (called a "low emission angle") while the surface is obliquely illuminated (called a "high incidence angle"). The resulting views bring out surface morphology and are crucial to making a global map of Eros. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Oblique View of Eros' Crater
PIA02484
Sol (our sun)
Multi-Spectral Imager
| Title |
Oblique View of Eros' Crater |
| Original Caption Released with Image |
This 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. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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A Trio of Craters on Eros
PIA02488
Sol (our sun)
Multi-Spectral Imager
| Title |
A Trio of Craters on Eros |
| Original Caption Released with Image |
The Near Earth Asteroid Rendezvous (NEAR) spacecraft snapped the image on the left (Image of the Day Feb. 13, 2000 B) during its approach to Eros on Feb. 11, 2000, from a range of 2590 kilometers (1,609 miles). This image shows a heart-shaped depression about 5 km (3 miles) long. The image mosaic on the right was taken from 204 km (127 miles) on March 3, 2000 and reveals that the mysterious heart-shaped feature is actually 3 separate craters. The oblique lighting conditions and low resolution of the earlier image created the illusion of a heart shape. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros'North Pole
PIA02498
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros'North Pole |
| Original Caption Released with Image |
For 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 kilometers (127 miles), the asteroid's north pole is in the upper right of the frame. The whole scene is 7.4 kilometers (4.6 miles) across. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Two Very Different Asteroids
PIA02494
Sol (our sun)
Multi-Spectral Imager
| Title |
Two Very Different Asteroids |
| Original Caption Released with Image |
The NEAR Shoemaker spacecraft has scored two important firsts in the exploration of asteroids: it's the first to orbit an asteroid, Eros, and the first to encounter a denizen of the outer reaches of the asteroid belt, the C-type asteroid Mathilde. In a scheme that reflects how they have historically been a topic for astronomy, not geology, asteroids are classified into groups based on their colors as observed through telescopes. The two major classes of asteroids are called S-types and C-types. S-types, whose colors are consistent with "stony" or rocky compositions, prevail among asteroids that orbit closer to the Sun than the mid-point of the asteroid belt. Eros and the two asteroids encountered briefly by the Galileo spacecraft on its way to Jupiter -- Gaspra and Ida -- are all S-types. C-types like Mathilde have a dark gray color consistent with a "carbonaceous" composition, rich in carbon compounds and other dark materials. They prevail in the outer part of the asteroid belt. In this montage, Mathilde (at left) and Eros (at right) are shown at the same scale, as they were imaged by NEAR Shoemaker from about 1,800 kilometers (1,116 miles) on June 27, 1997, and February 12, 2000, respectively. Mathilde is 56 kilometers (35 miles) across, and Eros is 33 kilometers (21 miles) long and 13 kilometers (8 miles) wide. However, Mathilde's brightness is greatly exaggerated for viewing purposes -- it's actually six times darker than Eros, with about the same reflectivity as soot! Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Sunset on Eros
PIA02493
Sol (our sun)
Multi-Spectral Imager
| Title |
Sunset on Eros |
| Original Caption Released with Image |
Eros' 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. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros Color at Higher Resolut
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PIA02492
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros Color at Higher Resolution |
| Original Caption Released with Image |
As 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 kilometers (1,083 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 kilometers (175 miles) and shows much smaller details only 27 meters (89 feet) across. The higher spatial resolution (by a factor of six) 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. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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April Fool's Crater
PIA02495
Sol (our sun)
Multi-Spectral Imager
| Title |
April Fool's Crater |
| Original Caption Released with Image |
Lighting and viewing geometries make a huge difference in the appearance of Eros' surface features. One of the most striking examples is the 2.7-kilometer (1.68-mile) diameter crater shown in these two images. The image at left, looking at the crater nearly edge-on, was taken February 16, 2000, from a range of 341 kilometers (212 miles). The image at right was taken high over the crater on March 2, 2000, from a range of 226 kilometers (140 miles). In the first image the only visible part of the crater's interior is the far, bright wall, which at the time was well-lit. The lighting, in combination with the particular viewing angle, make the crater appear stunningly bright. In the second view, the brighter material occupies only part of the slightly-shaded interior, greatly reducing the overall brightness contrast between the crater and the surrounding terrain. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Topographic Profiles from th
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PIA02486
Sol (our sun)
Laser Rangefinder
| Title |
Topographic Profiles from the NEAR Laser Rangefinder |
| Original Caption Released with Image |
The NEAR Laser Rangefinder obtained this "staircase" altimetric profile from within the wall of the 6 kilometer (3.7 mile) diameter crater shown in the image inset. The profile represents ten minutes of data obtained from a range of 217 km (135 miles) on March 2, 2000. The purple points are a plot of radius from the center of Eros (left axis), and the blue points show the same measurements but with the overall trend removed (right axis). The laser track runs from left to right approximately in a line along the major axis of the red ellipse drawn on the image. The laser profile reveals a series of shallow depressions, about 50 to 80 meters (162 to 260 feet) wide and 5 to 10 meters (16 to 32 feet) deep, that may be a chain of pits or craters. Alternatively, the "staircase" profile may be the signature of a series of small ridges. The spatial structure and origin of the features producing the staircase will be revealed as the laser rangefinder accumulates elevation measurements during its one-year mapping mission of Eros. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Glimpses into Eros' Shadows
PIA02487
Sol (our sun)
Multi-Spectral Imager
| Title |
Glimpses into Eros' Shadows |
| Original Caption Released with Image |
This image mosaic, showing Eros' saddle and a shadowed feature to its left, was taken on March 3, 2000 from a distance of 204 kilometers (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 northeast illuminating a shadowed feature that consists of three 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. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros' North Polar Region
PIA02490
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros' North Polar Region |
| Original Caption Released with Image |
On 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 kilometers (127 miles). The area shown in the image is 10 kilometers (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 remains in darkness. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Eros' Aging Craters
PIA02497
Sol (our sun)
Multi-Spectral Imager
| Title |
Eros' Aging Craters |
| Original Caption Released with Image |
Eros' 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 kilometers (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. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Cratered Terrain on Eros
PIA02483
Sol (our sun)
Multi-Spectral Imager
| Title |
Cratered Terrain on Eros |
| Original Caption Released with Image |
This mosaic of 2 images, showing a cratered region of Eros located at the end of the elongated asteroid, was taken at a resolution of about 21 meters (69 feet) per pixel. A few of the craters show brightness (albedo) patterns on their walls, where the top portions of the walls are brighter than the surrounding terrain. The floors and lower portions of the walls of these craters have patches that appear darker than the surrounding terrain. A few boulders are also visible in this region. Some shallow, subdued troughs can also be seen trending vertically down the lower part of the asteroid. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Boulders, Boulders, Boulders
PIA02496
Sol (our sun)
Multi-Spectral Imager
| Title |
Boulders, Boulders, Boulders |
| Original Caption Released with Image |
One of the most striking features in NEAR Shoemaker images of Eros' surface is the abundance of very large boulders. This image of the southwestern part of the saddle region, taken March 6, 2000, from a range of 201 kilometers (125 miles), shows a particularly boulder-rich part of the surface. Many of the huge rocks are 50 meters (164 feet) or more in diameter. They are believed to be fragments of Eros' native rock, shattered over the eons by formation of impact craters. The impacting projectiles themselves were pulverized by the impact process and survive only as fine debris mixed into the regolith. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Rim of Saddle Region on Eros
PIA02485
Sol (our sun)
Multi-Spectral Imager
| Title |
Rim of Saddle Region on Eros |
| Original Caption Released with Image |
This image of the northeast rim of the saddle region on Eros was taken after NEAR entered into its 200 kilometer orbit on March 3, 2000. The resolution of this image is 20 meters (65 feet) per pixel. On the right are bright sinuous features associated with a ridge seen in previous images of the day. Parallel, closely spaced grooves are seen in the floor of the saddle. A cluster of boulders, ubiquitous on Eros, is seen in a small crater on the rim. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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The Sculptured Surface of Er
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PIA02480
Sol (our sun)
Multi-Spectral Imager
| Title |
The Sculptured Surface of Eros |
| Original Caption Released with Image |
NEAR takes several images mosaics of Eros daily for purposes of navigating the spacecraft. The one shown here was taken February 29, 2000, from a range of 289 kilometers (180 miles). It shows features as small as 30 meters (100 feet) across. All of the mosaics show the same territory over and over, but changes in lighting plus the gradual decrease in the spacecraft's range to the surface are both constantly bringing out new details. The very oblique illumination in this mosaic is ideal for bringing out small landforms. Many parts of the asteroid have "grooves," linear troughs about 100 meters (330 feet) wide and several kilometers long. Similar features have also been observed on other asteroids such as Gaspra, and they are especially numerous on Mars' moon Phobos. Their origin isn't completely understood, but formation of the grooves probably involves fracturing of the asteroid's subsurface in some way. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Looking Down
PIA02909
Sol (our sun)
Multi-Spectral Imager
| Title |
Looking Down |
| Original Caption Released with Image |
NEAR Shoemaker photographs Eros under a variety of lighting and viewing geometries suited to different science objectives. Taken with the Sun high in the sky, images with few shadows are best for mapping the color properties of the surface. Conversely, images taken from directly above a surface with oblique illumination are best for seeing landforms, because shadowing highlights the subtle shape changes on the asteroid's surface. This image was taken at the latter geometry on May 11, 2000, from an orbital altitude of 52 kilometers (33 miles). The whole scene is about 1.8 kilometers (1.1 miles) across, and shows features as small as 4 meters (13 feet). The rounded nature of the landforms results from formation of small impact craters over the eons. Sharp topography is eroded away by this process, and the surface is blanketed and smoothed by the fragmental debris, or "regolith." The large boulders scattered throughout the scene are the largest fragments of the rocky regolith. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Down, Down, Down
PIA02904
Sol (our sun)
Multi-Spectral Imager
| Title |
Down, Down, Down |
| Original Caption Released with Image |
As the NEAR Shoemaker spacecraft continues its descent to lower orbits around Eros, smaller and smaller surface details are becoming visible. This image was taken April 29, 2000, from an orbital height of 84 kilometers (52 miles), just before the engine firing that placed NEAR in a 50-kilometer (31-mile) altitude orbit. The image shows features as small as 7 meters (23 feet) across and boulders a mere tens of meters in size. The whole scene is 3.2 kilometers (2 miles) across. Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Light and Shadow
PIA02907
Sol (our sun)
Multi-Spectral Imager
| Title |
Light and Shadow |
| Original Caption Released with Image |
Eros' 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! Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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Pretty Sharp
PIA02912
Sol (our sun)
Multi-Spectral Imager
| Title |
Pretty Sharp |
| Original Caption Released with Image |
Pictures taken during the low-orbit phase of NEAR Shoemaker's mission to Eros are revealing the true appearance of an asteroid's surface. Eros is turning out to have diverse surface types ranging from flat to hilly, smooth to rocky, and monotonously cratered to unique in character. This picture was taken for "optical navigation," that is, plotting the spacecraft's course by tracking the positions of the landmarks below. It caught a spectacular view of a horizon sculpted by worn, degraded craters and punctuated by jagged boulders. The angular boulder at the center of the frame is about 60 meters (197 feet) tall, or two-thirds the length of a football field. Angular rocks are very common in nature, the corners form as a rock is chipped out of a larger mass. This image was taken May 18, 2000, from an orbital altitude of 50 kilometers (31 miles). The whole scene is about 1.4 kilometers (0.8 miles) across, and it shows features as small as 4 meters (13 feet). Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details. |
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