NEAR Entering Orbit Around Asteroid Eros

The NEAR spacecraft is about to enter orbit around the asteroid Eros on Valentine's Day -- only one rocket burn remains. This is NASA's first Discovery Mission and the first-ever mission to orbit an asteroid. NEAR stands for Near-Earth Asteroid Rendezvous. Eros is only about 11 miles across, and is considered a near-Earth asteorid because its orbit occasionally brings it closer (in astronomical terms) to Earth than most asteroids, which live in the main asteroid belt between Mars and Jupiter.

SwRI's Dr. Clark Chapman is a member of the joint imaging and IR spectrometer teams and Dr. Bill Merline is an associate team member.

SwRI's role in this mission begins early, however, as Dr. Merline leads the NEAR effort to search for small natural satellites around Eros. The most extensive satellite search will occur on Feb 10, as data are returned from the spacecraft's camera beginning at 11 am EST. We expect to be able to detect objects as small as 10 meters across.

The presence or absence of moons will help us undertand the origin and evolution of Eros in particular, and that of asteroids and the solar system in general. Our search may also alert us if there is any debris near the asteroid that could pose a danger to the spacecraft.

Also involved with the search are Dr. Chapman, Dr. William Colwell, and Dr. Peter Tamblyn, all also of the SwRI Boulder office. Drs. Chapman, Merline, and Tamblyn will study images as they are returned to the Applied Physics Lab, in Maryland, which operates the mission, while Dr. Colwell operates special software specifically developed for the search, from a SwRI Internal Research QuickLook. The search algorithms employ artificial intelligence technology and were developed in hopes that SwRI (and co-developers at JPL) will ultimately put similar algorithms aboard spacecraft for intelligent, automated decision-making, providing higher science return at lower cost.

This is not SwRI's only role, however. Dr. Chapman, an expert on asteroids and cratering, will lead the NEAR team in measuring the sizes and distributions of craters on the surface, giving us clues to the surface's history and age. Color variations on the surface and other geological features will also be of interest. Spectra of the asteroid will give an indication of the rocks and minerals composing Eros' surface. Other science teams will study the asteroid's magnetic field, its gravity field, its composition (using an X-ray and Gamma-ray spectrometer), and the detailed surface topography using a laser-ranging system.