PLEASE NOTE:


*

CCNet 21/2001 - 6 February 2001: EROS SPECIAL
---------------------------------------------


"After a fling and a rendezvous, it's time for NEAR to settle down."
James, R. Asker, Aviation Now, 5 February 2001


"This is the first time we've gotten up close and personal with one
of the objects that eliminated the dinosaurs."
--Edward J. Weiler, Associate NASA Administrator for Space
Science


"A highly porous body will not be so easily deflected by an
explosion, the experts tell us. This means that deflection by an
emplaced propulsion system that uses reaction mass mined from the
body becomes the method of choice: this is technology relevant to space
mining, accessing the resources of the asteroids for humanity's use.
It implies we should be researching how to mine asteroidal regolith,
and cometary mantle material, and solar powered steamrockets, and
steam powered 'regolith rockets', and mass drivers."
--Mark Sonter, 5 February 2001


(1) SMOOTH ATTEMPT TO LAND ON EROS
    Ron Baalke <baalke@jpl.nasa.gov>

(2) CLOSE-UP PICTURES OF EROS TO SHED LIGHT ON MYSTERIOUS IMPACT CRATERS
    Ron Baalke <baalke@jpl.nasa.gov>

(3) ATTEMPTS AT HARD LANDING SET FOR ASTEROID SPACECARFT
    Andrew Yee <ayee@nova.astro.utoronto.ca>

(4) NEARING A CRASH LANDING
    Scientific American, 5 February 2001

(5) NEW MAP OF PLUTO RELEASED
    Larry Klaes <lklaes@bbn.com>

(6) DARK SIDE OF A DIFFERENT MOON
    Andrew Yee <ayee@nova.astro.utoronto.ca>

(7) PLANET EARTH ON THE MOVE
    BBC Online News, 5 February 2001

(8) IMPACT HAZARD: SOME QUESTIONS FOR RUSSIAN NEO RESEARCHERS
    Worth Crouch <doagain@jps.net>

(9) EROS' DENSITY & THE LESSONS FOR PLANETARY DEFENSE
    Mark Sonter <sonter@camtech.net.au>

(10) HOLST AND THE PLANETS
     Don Barrett <barrett1@lvcm.com >
 
(11) PLUTO ROMANTICS, AGAIN
     Joshua Kitchener <staff@dot-comet.com>

===============
(1) SMOOTH ATTEMPT TO LAND ON EROS

From Ron Baalke <baalke@jpl.nasa.gov>

http://www.news.cornell.edu/releases/Feb01/NEAR.control.bpf.html

Images from outer space: Cornell researchers turn to telemetry and geometry
to capture distant asteroid

FOR RELEASE:  Feb. 5, 2001

Cornell University News Service
Contact:  Blaine P. Friedlander, Jr.
Office:  607-255-3290
E-mail:  bpf2@cornell.edu

ITHACA, N.Y. -- Will this be the gang that could shoot straight? For the
past year, engineers and computer programmers from Johns Hopkins
University's Applied Physics Laboratory (APL), assisted by NASA's Jet
Propulsion Laboratory (JPL) and the imaging team at Cornell University, have
been figuring out how to slew a spacecraft precisely and aim its camera
perfectly for the final act of its mission: alighting on an asteroid.

On Feb. 12 the Near Earth Asteroid Rendezvous spacecraft, known as NEAR
Shoemaker, will attempt to land on Eros, an Earth-crossing asteroid about
196 million miles from Earth. In mid-descent, an onboard camera will point
toward the surface and hopefully send back the best images ever from a
small, solar-system body.  The navigational prowess of APL and JPL will be
complemented by the imaging expertise of the Cornell research team.

"It's not like this craft is landing on a sphere. It's descending on a
potato-shaped rock that is 22 miles long, and the rock has a large,
saddle-shaped hole on one side.  The rock continuously spins end-over-end.
Geometry is forcing us to land there -- where there is more motion than at
the poles -- so that NEAR's solar panels face the sun, its antenna points to
Earth and its camera faces the asteroid," says Cornell space sciences
researcher Ann Harch.  "Other than that, it's easy."

Use of the navigation team's telemetry, geometry and other calculations --
for this never-before-attempted maneuver -- required unique software to
point the camera, and it took more than a year to perfect.  Harch and her
Cornell research colleagues Maureen Bell and Colin Peterson and programmer
Brian Carcich worked with APL (which built the spacecraft and is managing
the mission) to develop special computer software that, with great
precision, displays the shape of Eros and how it will look from the camera's
point of view. First an exact model of the asteroid's shape had to be
determined.  This shape-model software, called POINTS, developed by
Cornell's Jonathan Joseph, programmer analyst, and Peter Thomas, senior
research associate, correlates feature in thousands of images and plots the
asteroid's trajectory and orientation.  From that information, the program
calculates a detailed three-dimensional asteroid model.

Harch, Bell and Peterson then used Orbit, a computer program developed at
Cornell by Carcich, to design pointing commands for the multispectral
imaging camera. Orbit reads input data on the asteroid's location and spin
orientation, then shows where the craft and camera will point.  The program
also displays how the asteroid will look to the camera at each instant.

This information allowed Harch, Bell and Peterson to cobble together command
sequences that were uploaded to NEAR Shoemaker throughout the mission.  The
comands take about 17 minutes for the information to be received by the
distant spacecraft and the same amount of time for the craft to send back
confirmation that the data was received.

If all goes as planned, at 10:31 a.m. Eastern time on Feb. 12, the
spacecraft will commence firing a series of burns -- firing thrusters away
from the asteroid -- to brake the craft for an anticipated 7 mph landing.
Control commands to the onboard, multispectral camera will be uploaded to
the spacecraft.  However, if NEAR goes faster or slower than anticipated,
mission controllers at APL will be able to adjust the craft's onboard clock
to delay or advance the final photo sequence.  "The spacecraft literally has
to be in the right place at the right time" for the camera to function as
planned, says Harch.

Reflecting on the five-year mission, Harch says:  "This final week has been
such an emotional one. It was an extraordinary experience working with these
people to produce such a fabulous result, and all of us feel that way."

Adds Bell, "Getting this altogether has meant many, many late nights."

=========
(2) CLOSE-UP PICTURES OF EROS TO SHED LIGHT ON MYSTERIOUS IMPACT CRATERS

From Ron Baalke <baalke@jpl.nasa.gov>

http://www.news.cornell.edu/releases/Feb01/NEAR.landing.deb.html

Cornell imaging team hopes close-up pictures from asteroid landing will
solve puzzle of never-before-seen surface features

FOR RELEASE:  Feb. 5, 2001

Cornell University News Service
Contact:  David Brand
Office:  607-255-3651
E-mail:  deb27@cornell.edu

ITHACA, N.Y. -- As NASA's Near Earth Asteroid Rendezvous spacecraft, known
as NEAR Shoemaker, closes in on asteroid 433 Eros, Cornell University
astronomers hope that surface details as small as a hand-size rock will be
captured by the camera before the spacecraft bumps down on the
boulder-strewn surface Feb. 12.

Since last October, the NEAR imaging team has been puzzling over strange
surface features of Eros seen in new, high-resolution images.  There is the
hope that the close-up images taken in the final few minutes before the
spacecraft drops onto the surface will help to answer their questions about
the geology of the 22-mile-long asteroid more than 196 million miles (316
million kilometers) from Earth.

"Since last October we have seen details of Eros at 1 meter resolution that
we haven't seen anywhere else before and don't understand," says Cornell
astronomer Joseph Veverka, who heads the imaging team.  "That's why we are
so excited about getting close to the surface."

The landing -- what NASA is calling a "controlled descent" -- is a highly
risky maneuver, involving four thruster firings over four hours intended to
slow the rate of descent to 7 mph from 20 mph. In the final 45 minutes, when
the spacecraft is about 3.5 to 4.5 miles (about 6 to 7.5 kilometers) from
its landing site at the edge of the crater Himeros, the camera will begin
taking a new image about every 30 seconds.

The final picture will be captured at just 550 yards (500 meters) from the
surface, enough to capture details as small as perhaps 4 inches (10
centimeters) across.  Mission leaders at the Applied Physics Laboratory at
Johns Hopkins University, which built the spacecraft and manages the NEAR
mission, do not expect images to be transmitted from the surface because
Eros's spin and topography will almost certainly prevent communication
between Earth and the craft.

Why does Veverka's team want to get such a close look at Eros' surface
details?  Because, says Veverka, who is professor of astronomy at Cornell,
his team is frankly puzzled by what it has seen on Eros over the past few
weeks. Last October, with much of NEAR's mission accomplished, the
spacecraft was sent into orbit just 4 miles (about 6 kilometers) or so from
the asteroid's surface. For the first time the imaging team was seeing
details as small as a yard (.9 meter) across, compared with the
approximately 5.5 yards (5 meters) resolution that had been captured by the
camera since the spacecraft went into orbit around Eros on Feb. 14, 2000.

"Suddenly, we started seeing things we didn't expect and hadn't seen on
other surfaces in the solar system," says Veverka. "It's like another door
has opened."

The biggest surprise, says Cornell researcher Peter Thomas, who has been
interpreting the geology of the asteroid's surface, "is that some small
craters and other small depressions have flat, smooth floors, unlike most
craters you see on Eros and other objects.  It looks as if fine-grain
material has slid down the craters' sides and ponded in the bottoms."
Apparently, he says, there is some mechanism "we hadn't anticipated" that
moves fine-grain material around on the surface. Although gravity on Eros is
only one one-thousandth of that on Earth -- an average person would weigh
only an ounce or two -- it is still "very effective in gathering materials
in very flat floors on the bottom of depressions."

Another surprise, says Veverka, is the discovery that some small boulders
are surrounded by material that appears to have disintegrated from the
boulders' surfaces.  "There is some process that is very gentle that somehow
disintegrates rock. We haven't seen this on the moon, and we haven't seen
this before on Eros," he says.  "But it seems to be very common."

It is just possible, says Veverka, that the final image will be taken almost
at the surface itself. He explains that the camera will remain in focus
until about 220 yards (200 meters) from the landing site.  If the spacecraft
is still on course, it is possible that the camera will take one final image
and have time to send a partial image on its way to Earth before the
spacecraft touches down.  It takes 10 milliseconds for the exposure, 1
second to read the image into the spacecraft recorder and 30 seconds for the
data to emerge from the recorder.  The data then take 17 to 18 minutes to
reach Earth tracking stations.

The imaging team now is getting even higher-resolution images of these
features.  On Jan. 24 the spacecraft entered a close flyby sequence,
including a four-day orbit that produced images from as close as 2 miles
(3.2 kilometers) above the surface.  These new images are enabling the
Cornell imaging team to accumulate data at a resolution of about 1.1 yards
(1 meter).  "The hope is that during the descent we can improve this
resolution by perhaps a factor of 10 so that we can find out more about what
is going on there," says Veverka.

Related World Wide Web sites:  The following sites provide additional
information on this news release.  Some might not be part of the Cornell
University community, and Cornell has no control over their content or
availability.

o Near Earth Asteroid Rendezvous Mission: <http://near.jhuapl.edu/>

==============
(3) ATTEMPTS AT HARD LANDING SET FOR ASTEROID SPACECARFT

From Andrew Yee <ayee@nova.astro.utoronto.ca>

[From February 5, 2001 issue of AVIATION WEEK & SPACE TECHNOLOGY,
http://www.AviationNow.com/content/publication/awst/20010205/near.htm]

Attempt at Hard Landing Set For Asteroid Spacecraft
By JAMES R. ASKER/WASHINGTON

After a fling and a rendezvous, it's time for NEAR to settle down.

The NEAR Shoemaker spacecraft has completed a successful mission orbiting
and studying Eros for a year. So why not try to bring the Near Earth
Asteroid Rendezvous spacecraft to rest on the asteroid? Indeed, that's
exactly what controllers plan to do next week.

They're calling it a "controlled descent." But labeling it an attempt to
crash-land might be more to the point, for the spacecraft is not designed to
land. Even if all goes exactly as planned, it will hit the surface of Eros
at about 5-7 mph. It could easily tumble and break. And, controllers
admit they will have to be remarkably lucky to ever again hear from the
spacecraft once it is down.

The object of trying to maneuver NEAR onto the surface of Eros is not to
perform a flying tour de force, however, although adding to the skill set of
planetary mission controllers is an important, secondary objective.

Rather, the main reason to attempt a hard landing is to gather "bonus
science" on the way down. Pictures of the surface can be taken at as high
resolution as possible with this spacecraft's camera. With 5-10 cm. (2-4
in.) resolution, they will be 5-10 times better than the finest
resolution gathered during NEAR's regular mission.

That goal has led the NEAR team to lay out a flight plan that in some
details is even higher risk than is inherent in the stunt of landing a
non-lander. But with the 160,000 images and 11 million laser returns NEAR
has racked up in orbit about the asteroid -- more than 10 times the data the
mission set out to archive -- there is no reason not to attempt to get a
handful of images that show even smaller details on Eros' surface,
scientists say.

"The only risk is in not taking one at this point in the mission," said
mission director Robert Farquhar of Johns Hopkins University's Applied
Physics Laboratory (APL).

Edward J. Weiler, the associate NASA administrator for space science, is
comfortable with the high-risk plan, since NEAR has already completed all
its science objectives in spades.

"Basically, the mission is a total success story," Weiler said, and at $233
million in program costs, "a shining example of the faster-better-cheaper
philosophy."

Launched in 1996, NEAR arrived at Eros in February 2000 and was able to
compile a detailed catalog of information on one example of what were the
building blocks of planets. Weiler added, "This is the first time we've
gotten up close and personal with one of the objects that eliminated the
dinosaurs."

The first landing on an asteroid would be a fitting finale to a string of
firsts for NEAR. It was the first in NASA's Discovery program of lower cost
planetary missions and the first mission beyond Earth that the space agency
ever entrusted to an outside organization. NEAR also was the first
spacecraft ever sent beyond Mars that drew its electrical power from solar
arrays, not
nuclear devices.

Most significantly, NEAR was the first spacecraft to go into orbit around a
small body, and made Eros only the sixth object ever orbited by an
artificial satellite. That was no mean feat since Eros, a rocky, 21-mi.-long
lump has just 1/1000th the gravity of Earth.

NEAR's flight has not been a perfect performance, however. The biggest
malfunction was the early shutdown of the bi-propellant engine when NEAR was
first attempting to rendezvous with Eros. It spoiled the attempt and sent
NEAR flying past its quarry (AW&ST Jan. 4, 1999, p. 30). But the NEAR team
was able to design a maneuver to fling it back toward the asteroid and
rendezvous a year later.

The intended landing site is on "the saddle" of the potato-shaped asteroid,
a concave area the basic shape of which is probably due to a large impact
crater, which has been named Himeros. NEAR imaging team member Mark Robinson
of Northwestern University said it was selected because it is "an exciting
area, geologically" that presents the possibility of looking in detail at
two distinct terrains.

The landing attempt is set for Feb. 12. It will begin with a 20-sec. burn at
10:31 a.m. EST to take it out of its current orbit of 35 km. (22 mi.) from
the center of Eros.

THE FINAL TIMING CORRECTION of the descent sequence will occur at 1:31 p.m.
Then, the deorbit burn will be followed by four braking maneuvers -- at 2:16
p.m., 2:31 p.m., 2:47 p.m. and 2:59 p.m., lasting 3 min., 5 min. 12 sec., 6
min. and 4 min. 14 sec., respectively.

The spacecraft will descend at a nearly vertical angle and reach Eros'
surface at 3:04 p.m. Farquhar described it as "a fairly hard landing,"
comparing the descent rate to that of a World War II parachutist's landing.

The NEAR team estimates that it needs to effect a total of 24 meters/sec.
change in velocity on the spacecraft to bring it down on the surface, and
that the spacecraft has enough hydrazine to achieve about 30 meters/sec.
change.

The spacecraft should be able to relay two or three pictures a minute back
to Earth. If it lands as hoped, NEAR will come to rest with its camera
touching the surface and its antenna up. Even if it does, its view of Earth
will be blocked for 37 min. by the edge of a crater, and with Eros some 166
million mi. away, even in the best case, confirmation of NEAR's survival
would be delayed for more than an hour.

NEAR controllers have biased their plans toward getting good pictures, not
making the difficult landing. For example, the spacecraft will fire its
mono-propellant system four times, even though it will not be able to update
parameters of successive burns with information on how well the previous one
did. Theoretically, the spacecraft could do the burns with feedback from the
previous firing, but that could be tricky and therefore would put the
science objective at higher risk.

Alternatively, given the "open loop" nature of each burn, it would be more
conservative to employ a single firing. But Farquhar said the safer approach
was ruled out because four would allow for NEAR to spend more time at lower
altitudes.

There is no chance of gathering science data on the surface, Farquhar said.
He said, "The most we can hope for is a beacon from NEAR Shoemaker that says
it's still operating." He put the odds of the spacecraft landing in working
order and a signal from its omnidirectional antenna being picked up by
NASA's Deep Space Network at 1%.

"We'll look for a couple of days," Farquhar said, but no heroic efforts are
planned if NEAR Shoemaker does not "phone home."

Copyright 2001 AviationNow.com All Rights Reserved.

============
(4) NEARING A CRASH LANDING

From Scientific American, 5 February 2001

http://www.sciam.com/news/020501/2.html

Exactly one week from today on February 12th, the Near Earth Asteroid
Rendezvous (NEAR) Shoemaker spacecraft will end its five-year,
two-billion-mile mission, making what scientists hope will be a soft landing
on the asteroid 433 Eros (see animation). The spacecraft, which began
orbiting Eros on Valentine's Day last year, has collected 10 times more data
than originally planned, including about 160,000 images. "We have answered
the questions we had when the orbit began," says project scientist Andrew
Cheng from the Applied Physics Laboratory (APL). "But we also found many
other things we didn't expect to see and have questions we didn't know to
ask at the start of the mission. Scientists will be looking at these data
for years."

Many researchers are anxiously awaiting the last few photos NEAR Shoemaker
will snap next Monday, which will provide them with the closest look yet at
a small celestial body. They estimate these pictures could show surface
features as small as four inches across. The scientists are also eager to
attempt the craft's controlled decent onto Eros' 6-mile wide "saddle" area.
"With the spacecraft just about out of fuel and our science objectives met,
this is a great way to end a successful mission," says NEAR Mission Director
Robert Farquhar of APL. "It's all bonus science. It's never been tried
before and it certainly is a complicated set of maneuvers, but at this point
the only real risk is not taking one."

The plan is to begin moving NEAR Shoemaker out of its current orbit at about
10:31 a.m., Eastern Standard Time (EST). A series of thruster firings will
then slow the spacecraft down from a speed of about 20 miles per hour to 5
miles per hour. It should drift to the surface on its side, aiming its
telescopic camera towards the landing site. The estimated arrival time is
just after 3 p.m. EST. Mission operators intend to use blurring photos,
altitude data from the spacecraft itself, Doppler tracking and eventually,
the loss of a signal, to determine when NEAR Shoemaker actually lands.

"The whole sequence of engine burns has to go right, or it might not be a
very soft touchdown," Farquhar says. "The unknown nature of the surface
makes it hard to predict what will happen to the spacecraft, especially
since it wasn't designed to land. The most we can hope for is a beacon from
NEAR Shoemaker that says it's still operating." --Kristin Leutwyler

Copyright 2001, Scientific American

===========
(5) NEW MAP OF PLUTO RELEASED

From Larry Klaes <lklaes@bbn.com>

Astronomers from the Southwest Research Institute have produced a new map of
the surface of Pluto that shows a mysterious dark streak just above the
equator. The map was produced by watching the shadow of Pluto's moon Charon
as it passed across the surface of the planet. Each time Charon passed in
front, the astronomers were able to measure the variations in light on the
planet's surface. We won't know if the map is accurate until Pluto is
visited by spacecraft - this isn't expected to happen any earlier than 2015.


Original Source:
http://www.boulder.swri.edu/recent/pluto_map.html

Internet Coverage:
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1150000/1150197.stm
http://www.cosmiverse.com/space02050102.html

Similar Stories:
http://www.universetoday.com/html/topics/pluto.html

Related Sites:
http://www.universetoday.com/html/directory/astronomy.html

Related Books:
http://www.universetoday.com/html/books/pluto.html

============
(6) DARK SIDE OF A DIFFERENT MOON

From Andrew Yee <ayee@nova.astro.utoronto.ca>

[http://www.nature.com/nsu/010208/010208-4.html]

Monday, 5 February 2001

Dark side of a different moon
By PHILIP BALL

When the Genoese astronomer Giovanni Domenico Cassini discovered two new
moons orbiting Saturn in 1671, he noticed something curious about one of
them, now called Iapetus. "One part of [its] surface," he said, "is not so
capable of reflecting to us the light of the Sun which maketh it visible, as
the other part is".

He was right. A dark blotch disfigures Iapetus on its leading side. New
research suggests this mysterious black eye may be a debris from one of
Saturn's other moons, Titan [1].

Titan is the one of the most captivating of the 30 or so moons identified
around Saturn so far. It is slightly bigger than the planet Mercury and has
an atmosphere thicker than the Earth's -- composed of nitrogen and
hydrocarbons such as methane. Its surface is far colder than the Earth's,
but warm enough to perhaps support lakes and rivers of ethane -- a kind of
gasoline planet.

In comparison, Iapetus, a smaller world just 700 kilometres across, is a
bleak and barren place, with virtually no atmosphere and a rocky, cratered
surface similar to that on our own moon. Except, that is, for the dark
plains covering most of one hemisphere. What is this stuff, and where did it
come from?

Some astronomers think it formed from reactions between methane and ammonia,
released from Iapetus's rocky guts by volcanic eruptions. Others suggest
that the moon swept up the dark dust from space. After studying light
reflected from it, Tobias Owen of the University of Hawaii and his
colleagues now offer a fresh explanation.

The murky deposit absorbs much of the sunlight falling on it, but enough
reflects to carry a potential fingerprint of the material's identity. Just
as plant chlorophyll has its own distinctive green that identifies it in the
light reflected from a leaf, so the light spectra from Iapetus's dark patch
can reveal what chemical substances it contains.

From such observations, researchers have previously concluded that the
material is largely organic: made from carbon-containing compounds. One of
their favourite chemical candidates is a kind of polymer formed from
hydrogen cyanide, called poly-HCN.

But to pin down exactly what Iapetus's dark stain is made from, astronomers
need measurements of the light spectra at longer, infrared wavelengths.
Owen's team obtained such spectra using the UK Infrared Telescope on Hawaii,
and then searched for a plausible mixture of ingredients that could be
behind them, like mixing pigments to match paint to a particular colour.

The best match, they say, comes from a blend of ice, 'amorphous carbon'
(basically like soot) and a solid substance called tholin -- a mixture of
organic molecules formed by passing electrical sparks through nitrogen and
methane gases. Both Titan and Neptune's moon Triton are believed to harbour
tholin on their surfaces.

A massive meteorite impact on Titan, the researchers say, could have sprayed
the organic matter into orbit around Saturn, staining Iapetus as the moon
passed through the debris. Perhaps, they add, the tiny, reddish moon
Hyperion, which orbits between Iapetus and Titan, is a relic of this impact.

1. Owen, T., C. et al. Decoding the Domino: the dark side of Iapetus. Icarus
149, 160-172 (2001).

Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE

===========
(7) PLANET EARTH ON THE MOVE

From BBC Online News, 5 February 2001
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1154000/1154784.stm

By BBC News Online science editor Dr David Whitehouse

Mankind will soon have the ability to move the Earth into a new orbit, say a
team of astronomers. The planetary manoeuvre may more than double the time
life can survive on our planet, they believe.

Our initial analysis shows that the general problem of long-term planetary
engineering is almost alarmingly feasible

Our Sun will increase its brightness in the next billion years or so, and if
the Earth stays in its present orbit it will be fried and all life
eliminated.

Using the well-understood "gravitational sling shot" technique that has been
employed to send space probes to the outer planets, the researchers now
think a large asteroid could be used to reposition the Earth to maintain a
benign global climate.

It is an "alarmingly simple" technique, the astronomers say. It could ensure
humanity's survival and even allow our descendants to alter our Solar System
to move moons and planets to make new Earths.

The astonishing idea has been put forward by Don Korycansky, of the
University of California, along with Gregory Laughlin, of the US space
Agency Nasa, and Fred Adams, of the University of Michigan.

FULL STORY at
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1154000/1154784.stm

============================
* LETTERS TO THE MODERATOR *
============================

(8) IMPACT HAZARD: SOME QUESTIONS FOR RUSSIAN NEO RESEARCHERS

From Worth Crouch <doagain@jps.net>

Dear Dr. Peiser:

Russian scientists were quoted in CCNet, 5 February 2001 as saying things
about asteroids, or any danger from space, that seem to conflict with views
and data from both NASA and the January 2001 issue of SPACE UK, as it was
reported in CCNet. The following Russian statements seem to need greater
explanation as I indicate by my comments after each statement:

1) Professor Mikhail Smirnov of Russia's Institute of Astronomy was quoted
as saying, "The flight paths of all asteroids expected near Earth's orbit
between now and 2176 have been mapped, and none of them foresee a collision
with the Earth, though longer-term forecasting is not possible without more
powerful computers." According to the Near Earth Object Task Force Chairman
Harry Atkinson, as he referred to NASA, not all of the NEO's which I assume
includes NEAs have been discovered. If this is the case how could a more
powerful computer be if assistance in predicting unknown asteroids and their
unknown orbits?

2) Also using the same unknown asteroid reasoning why is the Professor so
sure when he elaborated, "He added that intermittent rumours an asteroid was
going to collide with the planet were "fiction or a sign of incompetence." I
sight NASA's data bank and surprised scientists, "One of the most recent
close calls occurred on March 23, 1989, when an asteroid 0.25-mile (0.4-
kilometer) wide came within 400,000 miles (640,000 kilometers) of Earth.
Surprised scientists estimated that Earth and the asteroid -- weighing 50
million tons and traveling at 46,000 miles/hour (74,000 kilometers/hour) --
had passed the same point in space just six hours apart."

3) In his conclusion Professor Smirnov believes that a real asteroid threat
does not exist when he states, "If a real asteroid threat does appear in the
future, humankind will undoubtedly find a way to prevent it." However,
hasn't it been determined by most in the scientific community that, "On June
30, 1908, a small asteroid 330 feet (100 meters) in diameter exploded over
the remote region of Tunguska in Siberia, devastating more than half a
million acres of forest." If the 1908 asteroid had exploded over Moscow I
think Professor Smirnov must conclude that it had been a real threat. Again
according to the Near Earth Object Task Force Chairman Harry Atkinson, " . .
. 300 metre asteroids are much more numerous and can cause great damage on a
regional scale. If a 300 metre object hit the sea - the most likely place,
as water covers two-thirds of the Earth's surface - the large tsunami (tidal
wave) created would have very serious consequences on the coastlines of
countries many thousands of miles away." Professor Smirnov did, however, to
his credit acknowledge the threat of smaller unknown asteroids, but not as
a, "...real asteroid threat ..."

4) Furthermore, Vadim Simonenko of Russia's Federal Nuclear Centre at
Snezhinsk (Chelyabinsk-70) said, " . . technology would be able to cope with
any danger by finding the hazardous object in space and by adopting measures
able to prevent its impact with Earth." However, since we currently don't
know how many asteroids pose a potential threat to the Earth, and since
comets can progressively change their orbits by the jet action of their
warming gas, the mathematics currently available to determine their orbits
is a chaotic estimate at best. Moreover, how would Vadim Simonenko handle a
comet like Shoemaker-Levy 9 if it were on a collision course with the Earth?

5) Finally, Vadim Simonenko expresses his belief by saying, "But global
catastrophes occurred only once every 100,000 to one million years, with
consequences ranging from degradation of the human race to its total
elimination, . . ." However, the scientific community only recently deduced
that the 1908 Tunguska explosion resulted from as asteroid impact and
scientists were on that sight almost immediately. Furthermore, only in that
last 30 years has the credibility of global catastrophes such as
asteroid/comet impacts and massive volcanic eruptions been accepted in the
scientific community as worthwhile theories for ecosystem changes.
Therefore, I find it rather presumptuous to assign credibility to
prehistoric data that at best only approximated fractionally what may have
actually occurred. Furthermore, when was the Earth's last great asteroid
collision? I don't think Vadim Simonenko or anyone has the data to enable
them to forecast an asteroid or comet Earth collision with any certenty. In
fact because of the mathematical concept of chaos, even rainy weather
forecasting is imperfect. All that is certain is that it will happen.

I would welcome any explanations for the Russian ideas and projections on
asteroid impacts that could clear up my questions on their rational.

Sincerely,

Worth F. Crouch
(Talako)

=================
(9) EROS' DENSITY & THE LESSONS FOR PLANETARY DEFENSE

From Mark Sonter <sonter@camtech.net.au>

Dear Benny,

Following on from Andrew Yee's posting of the report by McKie:

NEAR data now appears to suggest that Eros' density is "too low", implying
macroscopic or microscopic voids, a highly porous body. This was found also
with Mathilde.

A highly porous body will not be so easily deflected by an explosion, the
experts tell us.

This means that deflection by an emplaced propulsion system that uses
reaction mass mined from the body becomes the method of choice: this is
technology relevant to space mining, accessing the resources of the
asteroids for humanity's use. It implies we should be researching how to
mine asteroidal regolith, and cometary mantle material, and solar powered
steamrockets, and steam powered 'regolith rockets', and mass drivers.

Mark Sonter

==========
(10) HOLST AND THE PLANETS
 
From Don Barrett <barrett1@lvcm.com >
 
Dear Phil Plait:

I know Kent's MO, and the actual story regarding Holst and Pluto is
incorrect.   In fact, Holst started working on Pluto.  Partially completed
he suffered a  stroke and attempted to do what Delius did, that is dictate
the remainder to  one of his students.  Holst found this unsatisfactory and
decided not to  finish.  The quote attributed to him came from somewhere but
not Gustav.  This information comes from rather good authority.  While a
student at Oxford, I studied under Holst's best friend, Sir Adrian Boult.
In addition, I was fortunate enough to meet Imogen Holst, the composer's
wife.  The info re Pluto came from these two sources.  Kent is something of
a showman, and I take real exception to his interpretation of the work,
which he is claiming as his own (as a conductor).  Adrian Boult conducted
the first performance with the composer present.  I have to believe his
interpretation to be the most authentic.  Kent takes major liberties with
tempo especially in Uranus and Jupiter.  As far as I'm concerned, my Pluto
is as good as his and who is to say what Holst would have written had he be
able to complete the work. Incidentally, the remarks about Mahler are also
incorrect.  The tenth   symphony was never finished, nor was the last
movement even sketched.  The   symphony was completed under a commission by
the New York Philharmonic by  Derek Cook using what he believed to be
Mahlerian themes.

If the science world wishes to declare Pluto a non-planet then I think the
same case can be made for Jupiter and Saturn.  After all, they are really
failed stars without sufficient mass to initiate nuclear fusion.
 
Don Barrett is a producer-director working in High Definition
Television/Film Production. He has  recently produced a long form music
video documentary entitled, "Patrick Stewart narrates 'The Planets"
(http://www.don-barrett.com).

========
(11) PLUTO ROMANTICS, AGAIN

From Joshua Kitchener <staff@dot-comet.com>

Dear Benny,

Mr. Atkinson affirms in his letter to you that he is concerned about "...the
opinions of non-astronomers in all this, the men and women and children 'in
the street'."

And that deplanetizing Pluto is tantamount: "not just (to) re-writing
science textbooks, it's re-writing history, and it's re-writing it with
cold, perhaps even arrogant disregard for the image non-astronomers have of
Pluto."

Most shockingly, Mr Atkinson also urges that scientists to care not to
offend "...the people who buy astronomy books, watch Discovery Channel
programs - and buy planetarium tickets".

These statements epitomize the position of the Pluto Romantics, who seem to
have mistaken Astronomy for Astrology.

Ever notice how religious zealots try to convert others to their faith? This
compulsion is usually a reflection of their own lack of faith in what they
are preaching. I'm always a little suspicious of astronomy clubs that
actively "reach out" for new members.

Mr. Atkinson, please do not worry that the truth about Pluto will render
Astronomy unattractive to the layperson. There have always been people
interested in Astronomy, and there always will be.

Quite sincerely,
Joshua Kitchener
Publisher, NearEarth.net Magazine
http://NearEarth.net


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