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. Click here for desktop ready version
Shoemaker Moves In For A Nearer Look
 Laurel - April 5, 2000 - The true nature of Eros becomes a bit clearer -- literally -- as NEAR Shoemaker moves into a lower orbit this weekend.

Shortly after 9 p.m. (EST) on Saturday, April 1, the spacecraft will fire its thrusters for about 40 seconds and begin gradually descending into position to start a 62-mile (100-kilometer) orbit on April 11.

Since March 3, NEAR Shoemaker has been in a nearly circular orbit some 127 miles (205 kilometers) from the center of Eros. NEAR team members say halving the spacecraft's distance to the rotating space rock will yield sharper images of the abundant geological features on the asteroid's surface, giving them a chance to learn more about the relationship between the many ridges, grooves and craters.

Earlier than expected, the team is also gathering information on the asteroid's elemental makeup. With the help of three solar flares on March 22 and 23, the spacecraft's X-Ray/Gamma Ray Spectrometer (XGRS) picked up additional fluorescent "signatures" of magnesium, aluminum, silicon, calcium and iron on the Eros surface.


The X-ray/Gamma-ray Spectrometer (XGRS) will develop global maps of the elemental composition of the surface of Eros. The instrument remotely senses characteristic x-ray and gamma-ray emissions to determine composition. Solar excited x-ray fluorescence in the 1 to 10 keV range will be used to measure the surface abundances of Mg, Al, Si, Ca, Ti, and Fe with spatial resolutions down to 2 km. Gamma-ray emissions in the 0.3 to 10 Mev range will be used to measure cosmic-ray excited elements O, Si, Fe, H and naturally radioactive elements K, Th, U to surface depths on the order of 10 cm.
The readings were similar to those the XGRS detected during a solar flare on March 2 -- from four times the distance the instrument is designed to operate.

"From that distance, the readings verify that the instrument has the sensitivity we need," says Dr. Jacob Trombka, XGRS instrument team leader from NASA's Goddard Space Flight Center. "They continue to show us that the calibration is on target and the instrument is working as it should."

NEAR Shoemaker is about 135 million miles (218 million kilometers) from Earth, moving 3 miles an hour around Eros. The spacecraft is six weeks into its historic, yearlong mission to study the asteroid.

NEAR NEWS
 Shoemaker Flys With Eros Nearby
 by Andrew Cheng
NEAR Project Scientist
 Laurel - March 22, 2000 - Last week the NEAR spacecraft was renamed "NEAR Shoemaker," in honor of the late Eugene M. Shoemaker, a pioneer in the study of asteroid and comet impacts on Earth and other planets.

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