archive-1: SETI [ASTRO] NEAR's Eros Flyby Movie
SETI [ASTRO] NEAR's Eros Flyby Movie
Larry Klaes ( lklaes@bbn.com )
Thu, 21 Jan 1999 15:26:16 -0500
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>Date: Thu, 21 Jan 1999 18:20:20 GMT
>From: Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
>To: astro@lists.mindspring.com
>Subject: [ASTRO] NEAR's Eros Flyby Movie
>Sender: owner-astro@brickbat12.mindspring.com
>Reply-To: Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
>
>
> NEAR's Eros Flyby Movie
> MPEG Movie (2.3 MB)
> http://near.jhuapl.edu/iod/000/index.html
>
> This movie shows the asteroid Eros as seen from the Near
> Earth Asteroid Rendezvous (NEAR) spacecraft on December
> 23, 1998, when NEAR flew within 2320 miles (3830
> kilometers) of the asteroid. Eros, a very elongated,
> cratered object about 18 by 8 miles (30 by 14
> kilometers) across, is seen rotating with a period of
> just over 5 hours.
>
> The movie shows about two-thirds of a rotation of Eros.
> The first view, taken at 10:44 AM EST from a range of
> 7150 miles (11,890 km), shows about half of the dayside
> of Eros (phase angle 87°). The movie ends at 2:05 PM
> EST, just after closest approach, when only a tiny
> portion of the dayside of Eros is seen (phase angle
> 119°). During the movie, the spacecraft's view of the
> asteroid changed dramatically. As is the case with most
> asteroids, Eros is rotating uniformly about a fixed
> axis, and is not tumbling randomly through space.
>
> A firing of NEAR's main engine at 5 PM EST December 20,
> designed to match the spacecraft's velocity with Eros's
> 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 were determined to be
> healthy and operational. Within hours, a flyby
> observation sequence was developed and uploaded to the
> spacecraft. 1026 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 during the flyby
> yields bounds on the asteroid's mass and density.
>
> The main engine was fired successfully on January 3,
> 1999, placing NEAR on-course for a February 2000
> rendezvous. 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).
>
>