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(meteorobs) Excerpts from "CCNet DIGEST, 22 January 1999"


------- Forwarded Message

From: Benny J Peiser <b.j.peiser@livjm.acdot uk>
To: cambridge-conference@livjm.acdot uk
Subject: CCNet DIGEST, 22/01/99
Date: Fri, 22 Jan 1999 11:17:54 -0500 (EST)

CCNet DIGEST, 22 January 1999
-----------------------------
...

(2) POSSIBLE METEORITE IMPACT IN MINNESOTA
    John Kalina <jkalina@uswestdot net>=20

(3) NEAR EROTIC MOVIE=20
    Ron Baalke <BAALKE@kelvin.jpl.nasadot gov>=20
...

(6) REMOTE AGENT: TO BOLDLY GO WHERE NO AI SYSTEM HAS GONE BEFORE
    N. Muscettola et al., NASA, AMES RES CTR
...

-------------------------------------------------------------------

(2) POSSIBLE METEORITE IMPACT IN MINNESOTA

>From John Kalina <jkalina@uswestdot net> [as posted on the meteorite-list]
=20
I caught the tail end of a local TV news cast of a possible fall in=20
west central Minnesota. Seems it landed on a lake, or lakes smashing  a =

hole (2-4 ft.dia) through the ice in at least one area. It happened on=20
atwater and foot lake near the town of Willmar. More information can be =

had at www.startribune.com or www.pioneerplanet.com  Maybe another=20
false alarm.

- ------------------

>From PIONEER PLANET, 21 January 1999
http://www.pioneerplanet.com/docs/0121mystery.htm
=20
Roar, hole through ice leaves Atwater residents wondering about=20
meteorite
=20
ATWATER, Minn. (AP) -- An unusual hole in the ice of a lake,=20
discovered after an early dawn roar in the sky, is leaving=20
authorities in this west-central Minnesota town wondering if it was=20
caused by a meteorite.
=20
A woman reported that after the roar rattled windows in her senior =20
citizen apartment complex Sunday, she stumbled out of bed, peered out=20
the window and noticed a dark hole in the ice of Tadd Lake.
=20
Atwater Police Chief Reed Schmidt said the woman was reluctant to=20
report the incident and insisted on remaining anonymous lest her=20
friends found out and questioned her sensibilities (sic).
=20
Schmidt thinks the 2- to 3-foot hole was caused by an object that=20
plummeted from the sky and has called a geologist for advice.
=20
He said it doesn't appear the object was a piece from an airplane. He=20
said the object must have been very hot when it landed because it left=20
no crash impact on the ice but made an "unusual imprint."
=20
He said the level area of open water in the small lake has a "beautiful =

star-shaped pattern" around the edges.
=20
Atwater Fire Chief Greg Tauer said he was not very curious about the=20
mystery object until he saw the hole in the ice.
=20
"Something from the sky made it," he said. "How did it get there? What=20
caused it? We want to find out what it is."
=20
Tauer said unless somebody objects, divers from the Atwater Fire=20
Department are scheduled to dive into the hole at 1 p.m. Saturday.
=20
"It's driving me crazy wondering what's there and not be able to see=20
it," Schmidt said. "But if it's something that's valuable for them=20
(geologists), I don't want to mess up their possibilities of finding=20
it."
=20
Copyright 1999, AP

-------------------------------------------------------------------
(3) NEAR EROTIC MOVIE=20

>From Ron Baalke <BAALKE@kelvin.jpl.nasadot gov>=20
=20
NEAR's Eros Flyby Movie
MPEG Movie (2.3 MB)
http://near.jhuapldot edu/iod/000/index.html=20
=20
This movie shows the asteroid Eros as seen from the Near Earth=20
Asteroid Rendezvous (NEAR) spacecraft on December 23, 1998, when NEAR=20
flew within 2320 miles (3830 kilometers) of the asteroid. Eros, a=20
very elongated, cratered object about 18 by 8 miles (30 by 14
kilometers) across, is seen rotating with a period of just over 5=20
hours.
=20
The movie shows about two-thirds of a rotation of Eros. The first=20
view, taken at 10:44 AM EST from a range of 7150 miles (11,890 km),=20
shows about half of the dayside of Eros (phase angle 87=B0). The movie=20
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=B0). During the =

movie, the spacecraft's view of the asteroid changed dramatically. As=20
is the case with most asteroids, Eros is rotating uniformly about a=20
fixed axis, and is not tumbling randomly through space.
=20
A firing of NEAR's main engine at 5 PM EST December 20, designed to=20
match the spacecraft's velocity with Eros's for insertion into orbit=20
around the asteroid, was aborted by the spacecraft. Contact with=20
ground controllers was temporarily lost, but was regained at 8
PM EST December 21 when autonomous spacecraft safety protocols took=20
over and transmitted a signal to the ground. All spacecraft systems=20
were determined to be healthy and operational. Within hours, a flyby
observation sequence was developed and uploaded to the spacecraft.=20
1026 images were acquired by the multispectral imager, to determine=20
the size, shape, morphology, rotational state, and color properties=20
of Eros, and to search for small moons. The infrared spectrometer=20
measured spectral properties of the asteroid to determine what=20
minerals are present, and the magnetometer searched for a natural=20
magnetic field. Analysis of the spacecraft radio signal during the=20
flyby yields bounds on the asteroid's mass and density.
=20
The main engine was fired successfully on January 3, 1999, placing=20
NEAR on-course for a February 2000 rendezvous. Eros is NEAR's second=20
asteroid encountered. On June 27, 1997, NEAR flew by the main-belt=20
asteroid Mathilde at a range of 1212 kilometers (750 miles).

-------------------------------------------------------------------
(6) REMOTE AGENT: TO BOLDLY GO WHERE NO AI SYSTEM HAS GONE BEFORE
 =20
N. Muscettola*), P.P. Nayak, B. Pell, B.C. Williams: Remote Agent: to=20
boldly go where no AI system has gone before. ARTIFICIAL INTELLIGENCE,=20
1998, Vol.103, No.1-2, pp.5-47
=20
*) NASA,AMES RES CTR,MS 269-2,MOFFETT FIELD,CA,94035
 =20
Renewed motives for space exploration have inspired NASA to work=20
toward the goal of establishing a virtual presence in space, through=20
heterogeneous fleets of robotic explorers. Information technology,=20
and Artificial Intelligence in particular, will play a central role=20
in this endeavor by endowing these explorers with a form of=20
computational intelligence that we call remote agents. In this paper=20
we describe the Remote Agent, a specific autonomous agent=20
architecture based on the principles of model-based programming,=20
on-board deduction and search, and goal-directed closed-loop=20
commanding, that takes a significant step toward enabling this=20
future. This architecture addresses the unique characteristics of the=20
spacecraft domain that require highly reliable autonomous operations=20
over long periods of time with tight deadlines, resource constraints,=20
and concurrent activity among tightly coupled subsystems. The Remote=20
Agent integrates constraint-based temporal planning and scheduling,=20
robust multi-threaded execution, and model-based mode identification=20
and reconfiguration. The demonstration of the integrated system as an=20
on-board controller for Deep Space One, NASA's first New Millennium=20
mission, is scheduled for a period of a week in mid 1999. The=20
development of the Remote Agent also provided the opportunity to=20
reassess some of Al's conventional wisdom about the challenges of=20
implementing embedded systems, tractable reasoning, and knowledge=20
representation. We discuss these issues, and our often contrary=20
experiences, throughout the paper. (C) 1998 Published by Elsevier=20
Science B.V.

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