2000 Apr 2
NEAR Shoemaker Moving In for a Better Look at Eros
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 fired its thrusters for 36 seconds and began 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 the new orbit will yield sharper images of the asteroid's abundant geological features, and more information about its 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 readings were similar to those detected during a solar flare on March 2 -- from four times the instrument's designed operating distance.
"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 134 million miles (215 million kilometers) from Earth, moving just under 3 miles per hour around Eros. The spacecraft is six weeks into its historic, yearlong mission to study the asteroid.
