This montage of the asteroid Eros was assembled from
images acquired by the Near Earth Asteroid Rendezvous
(NEAR) spacecraft on Dec. 23, as the spacecraft flew by
the asteroid at a distance of 2,500 miles (4,100
kilometers) at 1:43 p.m. EST.
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Asteroid Eros
Taken By NEAR Spacecraft
December 23, 1998
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This montage shows the
first nine of 28 views of Eros that were obtained during
the flyby. The images were taken between 10:44 AM and
12:44 PM EST as the spacecraft range closed from 7300
miles (11,100) km to 3300 miles (5300 kilometers).
During that time, the asteroid completed nearly half of
a rotation. The smallest resolved detail is
approximately 1650 feet (500 meters) across.
A firing of the main engine at 5 PM EST December 20,
designed to slow the spacecraft for insertion into orbit
around the asteroid, was aborted by the spacecraft.
Contact with ground controllers was temporarily lost,
but was regained at 8 PM EST December 21 when autonomous
spacecraft safety protocols took over and transmitted a
signal to the ground. All spacecraft systems appear
healthy and operational. Within hours, a flyby
observation sequence was developed and uploaded to the
spacecraft. Over 1100 images were acquired by the
multispectral imager, to determine the size, shape,
morphology, rotational state, and color properties of
Eros, and to search for small moons. The infrared
spectrometer measured spectral properties of the
asteroid to determine what minerals are present, and the
magnetometer searched for a natural magnetic field.
Analysis of the spacecraft radio signal will yield
bounds on the asteroid's mass and density.
Options for rescheduling firing of the main spacecraft
engine are currently being examined, and could lead to
Eros rendezvous and orbit insertion as early as mid-1999
or as late as May 2000. Eros is NEAR's second asteroid
encountered. On June 27, 1997, NEAR flew by the
main-belt asteroid Mathilde at a range of 1212
kilometers (750 miles).
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.
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