CCNet 87/2001 - 16 July 2001

"From July 16 through July 22, 1994, pieces of an object designated
as Comet P/Shoemaker- Levy 9 collided with Jupiter. This [was] the first
collision of two solar system bodies ever to be observed, and the effects
of the comet impacts on Jupiter's atmosphere have been simply spectacular
and beyond expectations. Comet Shoemaker-Levy 9 consisted of at least 21
discernable fragments with diameters estimated at up to 2 kilometers."

"On the other hand, life could simply have arrived here in a
meteorite from Mars. This idea is "highly plausible -- always supposing
there was life on Mars in the first place", says Professor Paul
Davies. It's estimated about half a billion Martian rocks suitable for
carrying living microbes have reached Earth. Some would have burnt up. But
many would have landed safely, says Davies."
--Deborah Smith, Sydney Morning Herald, 14 July 2001

"Everyone is so busy discovering planets they don't feel ready to
sit down in committees and decide what to call them," laments Helene
Dickel, who chairs the nomenclature committee of the International
Astronomical Union, the international body that, among other things,
assigns official names to celestial bodies. Last August, at an IAU meeting
in Manchester, delegates failed to agree on how to name extrasolar planets.
The relevant subcommittees are now trying to hammer out an agreement in
time for the union's next big meeting, in Sydney in 2003. The planet
hunters have proposed a simple solution: giving the planets proper
--Tom Standage, The Guardian, 12 July 2001

    Andrew Yee <>

    Andrew Yee <>

    Weather News for July, Friday the 13th

    Ron Baalke <>

    Ron Baalke <>

DAY, TOO, 15 July 2001

    Goddard Space Flight Center, 12 July 2001

    Matthew Genge <>

    Andy Smith <>

     Kuiper Belt Electronic Newsletter, no. 18, July 2001


From Andrew Yee <>

Sydney Morning Herald, 14 July 2001
[ ]

Saturday, July 14, 2001

Here's looking at you, Earthling

Light and microbes offer new clues in the search for other life in the
universe, writes Deborah Smith.

The day we discover we are not alone in the universe, it could be thanks to
the research of a young Australian scientist, Dr Vikki Meadows. Some
researchers are convinced microbes will be found living on Mars in the
not-too-distant future. Others wait patiently at their telescopes and
computers for a much more intelligent ET to call Earth.

But Meadows believes the first sign of life elsewhere could simply be the
patterns of light emanating from a faraway planet.

Water and a hospitable atmosphere -- and even the existence of lowly
creatures such as bacteria -- should show up as tell-tale "biosignatures" in
the planet's radiation, she says.

Meadows heads a team at NASA's Jet Propulsion Laboratory in California that
has just received an $18million grant to create computer simulations of a
range of planets and life forms.

"Our theoretical studies will drive the design of the instruments that will
ultimately look for signs of life," says Meadows, who spoke at a conference
in Sydney this week to mark the establishment of the Australian Centre for
Astrobiology, at Macquarie University.

First, however, astronomers will have to locate Earth-like planets. More
than 60 planets outside our solar system have been discovered in the past
five years but they are all "hot giants" -- Jupiter-sized gas planets that
sit close to their suns and which are unlikely to sustain life.

Professor Malcolm Walter, director of the new NASA-affiliated astrobiology
centre, says Australia is a perfect place to study how life evolved on
Earth, and the kind of creatures that could exist elsewhere.

"We have an abundance of very ancient rocks that preserve the history of
microbial life on Earth, and we have a number of extreme modern environments
where we can sample microbes adapted to very different conditions," he says.

Tiny inanimate organisms may be nowhere near as exciting as little green
men. But just one discovery of life nearby, "be it only microbial life",
would resolve the age-old question of whether we are the result of a rare
chance event, says Dr Jeremy Bailey, of the Anglo-Australian Observatory, an
organiser of the conference.

"It would show that life forms easily, given a suitable planet, and would
indicate that we live in a universe teeming with life."

Life on Earth probably sprang up between 4 billion and 3.8 billion years
ago. The oldest fossil evidence of early life was found in
3.5-billion-year-old rocks in the Pilbara region of Western Australia in
1999. The fossilised egg-carton-shaped structures, called stromatolites,
were built by ancient bacteria.

Rocks from the same region which were 2.7 billion years old also revealed
the earliest known existence of organisms from the family to which we belong
-- the eukaryotes, whose cells have a nucleus. (The other two families are
bacteria and archaea.)

Last week, Walter added to Australia's notoriety with his team's discovery
of the world's oldest ecosystem -- 1.5-billion-year-old fossils of 10 new
species of primitive organisms that floated in a shallow sea once covering
the Northern Territory.

Walter is helping advise NASA on the best sites on Mars for seeking fossils
of the microbial life that could also have been abundant there three to four
billion years ago.

Deposits on the red planet associated with ancient hot springs would be
leading contenders, because geologists already are good at detecting these
mineral bodies.

The first extra-terrestrial life forms to be found are likely to be
"extremophiles", organisms which can withstand extreme environments, says Dr
Rick Cavicchioli of the University of NSW. He describes the many varieties
of extremophile bacteria and archaea on Earth as the "bungy jumpers" of the
microbial world.

"They thrive in ice, boiling water, acid, the water core of nuclear
reactors, salt crystals, toxic benzene and under pressure equivalent to two
elephants standing on a 10 cent piece."

Last year's discovery in Western Australia of 3.2-billion-year-old fossils
of microbes that survived in scalding temperatures on the ocean floor added
weight to a leading theory that the first life forms on Earth were
heat-loving extremophiles.

"Rather than a warm little pond, the cradle of life may have been a
sulfurous, subterranean inferno, not unlike a medieval vision of hell," the
discoverer, Dr Birger Rasmussen of the University of Western Australia, said
at the time.

All life on Earth is based on DNA, so there must have been one original
organism -- dubbed the Last Universal Common Ancestor, LUCA -- from whom we
are all descended.

Some genetic analysis places the heat-loving bacteria and archaea very close
to the beginning of this tree of life. New Zealand scientists, however, are
leading the challenge to this idea.
They are interested in RNA, rather than DNA -- a single strand of genetic
code found in all our cells, which DNA uses to makes proteins. Evidence is
growing that before DNA evolved on Earth, there was an RNA world, with
organisms that depended on this molecule to reproduce themselves.

Dr Anthony Poole, of Massey University, a speaker at the astrobiology
conference, says it is possible to reconstruct this world by looking at the
RNA "relics" found in today's creatures.

The vast amount of relics are found in our family, the eukaryotes, which
suggests that this line is the oldest.

Bacteria and archaea evolved later, possibly in order to survive in high
temperatures, Poole's research shows. His conclusion: "LUCA was not a
thermophile [heat-lover]".

On the other hand, life could simply have arrived here in a meteorite from
Mars. This idea is "highly plausible -- always supposing there was life on
Mars in the first place", says Professor Paul Davies, who gave a public
lecture to launch the centre.

It's estimated about half a billion Martian rocks suitable for carrying
living microbes have reached Earth. Some would have burnt up. But many would
have landed safely, says Davies.

Astrobiology had its beginnings in 1996 when NASA scientists including Dr
Everett Gibson made the momentous announcement that they had found evidence
of past life on Mars, in a small Martian rock discovered in Antarctica in

The finding has been under scientific attack ever since, which is as
expected, says Walter, because extraordinary claims require compelling

Gibson, a key speaker at the conference, presented research showing that two
more Martian meteorites contained similar evidence.

"Our hypothesis of possible early life on Mars was presented five years ago
and today we believe that it stands stronger than when we originally
presented," he says. "To date, no fatal strikes have been made on any of the
original lines of evidence."

A major problem for the meteorite find has been that no organisms small
enough to be responsible for the micro-fossils in it were known on Earth.
This changed three years ago when Dr Philippa Uwins, of the University of
Queensland, found microscopic, nanometre-sized organisms living in sandstone
from five kilometres under the West Australian seabed.

Dubbed nanobes, they are a similar size to the nanobacteria associated with
the Mars rocks. Uwins's team has succeeded in extracting DNA from the
controversial nanobes, a major step in eventually determining what kind of
creatures they are.

NASA has missions planned to search for life on Mars and on Europa,
Jupiter's icy moon. It is also planning space telescopes that will be able
to detect Earth-like planets. Maybe we should hope the instruments Meadows
helps design only detect microbes.

Dr Charles Lineweaver at the University of NSW has calculated that
terrestrial planets in the universe would be, on average, 1.8 billion years
older than Earth. Some life could have as much as a seven-billion-year head
start, he says.

discovery of nanobes, below, underlines the theory that life on Earth first
came from Mars, top. Main photograph taken by the Hubble Space Telescope on
June 26. Nanobe image: University of Queensland.

Copyright © 2001 Sydney Morning Herald. All rights reserved.


From Andrew Yee <>

From The Guardian, 12 July 2001,3858,4220071,00.html

Thursday, July 12, 2001
Planets by other names

There is more to naming a discovery than mere tradition, writes Tom Standage

By Tom Standage

On a chilly March night in 1781, an amateur astronomer called William
Herschel stood in his garden in Bath, peered into a home-made telescope, and
accidentally became the first person in recorded history to discover a new
planet. The other planets -- Mercury, Venus, Mars, Jupiter and Saturn, which
are easily visible to the naked eye -- had been known under various
mythological names since the dawn of humanity. So when it came to giving his
new planet a name, Herschel decided to break with tradition.

The mythological names favoured by the ancients, he declared, were
unsuitable "in the present more philosophical era". Instead, he proposed to
name the new planet Georgium Sidus, or George's star, in honour of his
patron, King George III. Astronomers across Europe groaned. Herschel was
brown-nosing; and, worse, it was simply wrong to refer to his discovery as a
star. Others raced to propose alternative names, including Astrea, Cybele,
Hypercronius, Minerva, Oceanus and
Neptune. Eventually the planet ended up with three names: the English stuck
with Georgium Sidus, the French opted for Herschel, and the Germans gave it
the mythological name Uranus, by which it is still known today. The first
attempt to name a planet in modern times had degenerated into farce.

But things are little better today. Since 1995, astronomers have discovered
more than 60 planets orbiting nearby sun-like stars. The planets are found
by scrutinising the stars' light for evidence of the "wobbles" caused by the
gravitational influence of orbiting planets. The discovery of these
"extrasolar" planets has become so routine that they are now announced in
batches; the latest lot, announced in April, consisted of 11 new planets,
more than there are in our own solar system. Dozens more are on the way:
planets are now being found at an average rate of more than one a month.

Yet planet hunters have been unable to decide how to name their finds.
Ironically, given Herschel's choice of name for his planet, the planets have
also been temporarily named as though they were stars. The first planet,
found orbiting a star called 51 Pegasi in 1995, has been dubbed 51 Pegasi b.
This is an extension of the scheme used to name binary and multiple stars,
in which the letter "a" is assigned to the star itself.

In some cases, stars have multiple planets. Upsilon Andromedae, for example,
has at least three planets, which are called b, c and d in order of
increasing distance from their parent star. But there problems with this
scheme. What if another planet is subsequently found orbiting between c and d?

Introducing a new d, and renaming d to e, would render meaningless any
scientific papers that refered to the planets by their old names. So a
number of alternative schemes have been proposed. One is to give the planets
roman numerals in order of discovery, as is done with the moons of Jupiter.
Another is to label the planets numerically by distance from, or time taken
to orbit, their parent stars. However, these quantities are not always known
accurately, so the names are subject to change.

"Everyone is so busy discovering planets they don't feel ready to sit down
in committees and decide what to call them," laments Helene Dickel, who
chairs the nomenclature committee of the International Astronomical Union,
the international body that, among other things, assigns official names to
celestial bodies. Last August, at an IAU meeting in Manchester, delegates
failed to agree on how to name extrasolar planets. The relevant
subcommittees are now trying to hammer out an agreement in time for the
union's next big meeting, in Sydney in 2003. The planet hunters have proposed
a simple solution: giving the planets proper names.

Michel Mayor and Didier Queloz, the Swiss astronomers who discovered 51
Pegasi b, the first extrasolar planet, have proposed naming it Epicurus,
after the Greek philosopher who first suggested that there might be a
"plurality of worlds". Geoffrey Marcy, an American astronomer whose team has
discovered more planets than any other, has suggested the mythological name
Bellerophon for the planet, after the Greek hero who tamed Pegasus, the
flying horse.

There is a certain simplicity to this approach. But, says Dr Dickel, it has
been ruled out because future space missions, such as NASA's SIM mission and
the European Space Agency's Eddington probe, are expected to find millions
of planets, and "trying to name millions of objects with individual names
isn't going to work".

This means that a general-purpose alphanumeric scheme will have to be
devised. If Herschel were still around, he would surely approve of the fact
that, in the present more philosphical era, mythological names will finally
have been abandoned. Or will they? Astronomers still seem inclined to apply
such names, at least to some planets. So in many ways, little has changed
since 1781.

[Tom Standage is the author of The Neptune File: Planet Detectives and the
Discovery of Worlds Unseen (Penguin, £6.99)]

© Guardian Newspapers Limited 2001


Space Weather News for July, Friday the 13th

Just yesterday Comet LINEAR (C/2001 A2) was fading from view as it receded
from Earth. But now the volatile comet is again a naked-eye object. It's
glowing at about 4th magnitude in the pre-dawn sky with a pair of tails you
see through binoculars or a modest telescope. Comet LINEAR has a history of
crumbling then flaring as freshly exposed ice is vaporized by sunlight. What
will the comet do in the days ahead? See for yourself! Visit for details.


From Ron Baalke <>
July 15, 2001

One more scientific expedition has set off from Krasnoyarsk in Eastern
Siberia to the place where in its time the Tunguska meteorite fell. A
celestial body of tremendous mass and unknown origin, whose collision with
the earth happened near the Evenk village of Vanavara on June 30, 1908, is
to this day one of the main mysteries of the 20th century. Now the
expedition, made up of mostly scientists from Novosibirsk and Tomsk, is
going to study a new portion of the Tunguska virgin forest land, taiga. This
land, located nearly 20-25 kilometers away from the place seen over many
years as the epicenter, has never been seriously examined ever since. The
expedition will check the version whether or not the Tunguska meteorite was
a gigantic fragment of an ice comet.


From Ron Baalke <>,1299,DRMN_15_750375,00.html

'Canon City meteorite' goes on display

Softball-size object that hit garage in '73 to be in Springs

By Todd Hartman
Rocky Mountain News
July 14, 2001

A meteorite that slammed through the roof of a Canon City garage in 1973
will get its first prominent public display this weekend in Colorado
Springs. The sneak preview will precede by at least a year the meteorite's
permanent display in Denver.

Dubbed the "Canon City meteorite," the softball-size object hit the garage
floor of the house and exploded into pieces. It is one of only two
meteorites known to have hit a man-made structure in Colorado and one of
only 35 meteorites to have hit a structure in the United States.

Full story here:,1299,DRMN_15_750375,00.html


From, 15 July 2001

U.S. Ballistic Missile-Shield Program Passes Test; Mock Warhead Destroyed

By Jim Wolf

WASHINGTON (Reuters) - The Defense Department shot down a mock warhead over
the Pacific Ocean late on Saturday in a successful test of a controversial
anti-ballistic missile defense.

"The kill-intercept was confirmed by all our sensors," Air Force Lt. Gen.
Ronald Kadish, head of the Pentagon's Ballistic Missile Defense
Organization, told a news briefing.

But the results would take up to two months to analyze fully and "in all
probability" some of the test's objectives were unmet, he said.

Kadish termed it "one step on a journey" toward building a multilayered
shield against missiles that could be tipped with nuclear, chemical or
biological warheads.



From Goddard Space Flight Center, 12 July 2001

NASA-funded Earth Science researchers have discovered that during periods of
increased solar activity much of the United States becomes cloudier,
possibly because the jet stream in the troposphere moves northward causing
changes to regional climate patterns.

The new study supports earlier findings by suggesting there is a
relationship between increased cloud cover over the United States and the
solar maximum, the most intense stage of activity on the Sun.

Previous studies have shown that during the solar maximum, the jet stream in
the Northern Hemisphere moves northward. The jet stream guides storms and
plays an important role in cloudiness, precipitation and storm formation in
the United States.

Dr. Petra Udelhofen, a NASA-funded researcher at the Institute for
Terrestrial and Planetary Atmospheres at the State University of New York at
Stony Brook, is the lead author of a paper that discusses this topic,
appearing in the July 1 issue of Geophysical Research Letters.

"Based on these results and because the location of the jet stream
influences cloudiness," said Udelhofen, "we suggest that the jet stream
plays an important role in linking solar variability and cloud cover."

The jet stream is a ribbon of fast-moving air in the upper troposphere that
blows from west to east. Storms beneath the jet stream follow its path. A
shift in the jet stream can alter the location of clouds and precipitation
across the U.S.

The troposphere is the region of the atmosphere that extends from the
Earth's surface out to about 50,000 feet and is the focus of local, regional
and global weather research. The stratosphere extends above the troposphere
to about 150,000 feet and is the region where the ozone layer is formed.

The Sun's energy output varies over an 11-year cycle, sending more
ultraviolet radiation towards the Earth during times of increased activity.
While the Sun's total energy output only varies by about one-tenth of one
percent between periods of low and high solar activity, the ultraviolet
radiation that affects ozone production in the stratosphere can change by
more than 10 percent.

Ultraviolet radiation is absorbed in the Earth's stratosphere and creates
the protective ozone layer. When the ozone absorbs ultraviolet radiation, it
warms the stratosphere, which may affect movement of air in the troposphere
where clouds form.

Solar cycle effects of ultraviolet radiation absorption by ozone in the
stratosphere, its impact on atmospheric circulation and the location of
storm tracks have been the subject of recent Earth Science research.

"Our results show that cloudiness varies on average by about two percent
between years of solar maximum and minimum. In most parts of the U.S., cloud
cover is slightly greater in years of solar maximum," noted Udelhofen.

Though more investigation is needed to better understand just how changes in
the Sun's ultraviolet energy output is linked to atmospheric winds, the
study helps people identify potential large-scale mechanisms that affect
local and regional climates.

Scientists continue to investigate mechanisms that may link solar
variability with weather. These new results support the idea of a link
between stratospheric chemistry and meteorology, and support other recent
theoretical studies associated with the impact of stratospheric chemistry on
climate change and weather.

"It is important for future studies to identify and explain in detail the
link between solar variability, ozone, the atmospheric circulation and cloud
cover," Udelhofen said.

This research is part of the NASA Earth Science Enterprise program, which is
dedicated to understanding how Earth is changing and what consequences these
changes have for life on Earth.



From Matthew Genge <>

What happens when you write an article in an attempt to debunk a widely held
conspiracy theory? One thing is that your email inbox gets very full
remarkably quickly. Surprisingly most of the feedback and questions were
lucid and asked whether the Apollo samples could have been returned by an
unmanned mission similar to the Luna probes. My reply was to explain that
because the live footage shows the rocks being collected by the astronauts
NASA would have had to send two missions for every Apollo mission. The first
would have to be sent in secret to recover the rocks so the astronauts could
be filmed later collecting them. This sample return mission would need to
have a rover to collect such a variety of samples and, unlike the USSR
Lukinod rover, it would have to be robotic since it couldn't be controlled
from the ground. The rover would also have to be able to collect core
samples of the lunar regolith a task which is difficult enough today (the
Beagle II Mars lander designed by the Open University will achieve this feat
using an ingenious 'thunderbirds-like' mole). The second mission would, of
course, be the fake mission carrying the prerecorded communications to be
sent back from the Moon's surface.

Amazingly quite a few people replied to say thank you they were now
convinced. There is, however, no convincing some people. Even when we go
back to the Moon and find the flags, rovers, LEMs and the astronaut's
footprints there will be those who will firmly believe that this is just one
more twist in the conspiracy. One of these will be the person whose email
only identified them as "funky chicken" and believes that I am part of an
international conspiracy covering up everything from crop circles to
pyramids on Mars.

Finally, one further thing happens after such an article. You inexplicably
find yourself broadcasting live on radio to Australia, at 3.30 in the
morning, being interviewed by a man with the typical 'late-night radio'
voice whilst "Moon river" by Ben E King plays in the background.


Matt Genge


From Andy Smith <>

Hello Benny and CCNet,

As we remember Gene and SL-9 and all of those who have made it possible for
us to be here and to be aware of the great danger we face....while there is
still time.. and as we think of those, yet unborn, who are depending on us
to protect them from KALI;  we pray that we will have enough time to
prepare; that we will strenthen our resolve and sense of urgency; that we
will be given the governmental and public support needed, around the world,

(1) identify and track the 100,000 plus dangerous NEO, within the
next few decades (instead of centuries);
(2) to prepare a quick emergency deflection capability and
(3) to develop good civil emergency preparedness plans;

and that we will be more tolerant and respectful of one another and that we
will find ways to come together, as a single global team, to successfully
meet this great a spirit of mutual respect and love.

Here is a quick link to the SL-9 Home Page and those great pix:

May GOD Bless and Protect Us All


From the Kuiper Belt Electronic Newsletter, no. 18, July 2001

The Size and Albedo of The Kuiper-belt Object (20000) Varuna

D. Jewitt1, H. Aussel1, and A. Evans2
1 Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, Hawaii 96822, USA
2 Department of Physics and Astronomy, SUNY at Stony Brook, Stony Brook, New
York 11794-3800, USA

Observations over the last decade have revealed the existence of a large
number of bodies orbiting the Sun beyond Neptune. Known as the Kuiper-belt
objects (KBOs), they are believed to be formed in the outer reaches of the
protoplanetary disk around the young Sun, and have been little altered since
then. They are probably the source of short-period comets. The KBOs are,
however, difficult objects to study because of their distance from earth, so
even basic physical properties such as their sizes and albedos remain
unknown. Previous size estimates came from assuming an albedo with the
canonical value being 0.04. Here we report simultaneous measurements of the
thermal emission and reflected optical light of the bright KBO (20000)
Varuna, which allow us to determine independently both the size and the
albedo. Varuna has an equivalent circular diameter of D = 900+129-145 km and
a red geometric albedo of pR = 0.070+0.030-0.017. Its surface is darker than
Pluto's, suggesting that it is largely devoid of fresh ice, but brighter
than previously assumed for KBOs.

Published in: Nature, 411, 446 (2001 May 24)

For preprints, contact
or on the web at

Almost Planet X
S.C. Tegler1 and W. Romanishin2

1 Department of Physics & Astronomy, Northern Arizona University, Flagstaff,
AZ, 86011, USA
2 Department of Physics & Astronomy, University of Oklahoma, Norman, OK,
73019, USA

Optical and infrared observations of a bright object in the outer Solar
System reveal it to be surprisingly large -- almost as big as Pluto's moon.
It could be the first of many such discoveries.

Published in: Nature, 411, 423 (2001 May 24)
For preprints, contact

The Radial Distribution of the Kuiper Belt
C.A. Trujillo1 and M.E. Brown1
1 California Institute of Technology, MS 150-21, Pasadena, CA 91125, USA

We examine the radial distribution of the Kuiper Belt Objects (KBOs) using a
method that is insensitive to observational bias effects. This technique
allows the use of the discovery distances of all KBOs, independent of
orbital classification or discovery circumstance. We verify the presence of
an outer edge to the Kuiper Belt, as reported in other works, and we measure
this edge to be at  AU given any physically plausible model of the size
distribution. We confirm that this outer edge is due to the Classical KBOs,
the most numerically dominant observationally. In addition, we find that
current surveys do not preclude the presence of a second, unobserved Kuiper
Belt beyond R = 76 AU.

Published in: The Astrophysical Journal, 554, L95 (2001 June 10)
For preprints, contact
or on the web at

NICS-TNG Infrared Spectroscopy of Trans-neptunian Objects 2000 EB173 and
2000 WR106

J. Licandro1, E. Oliva1,2, and M. Di Martino3
1 Centro Galileo Galilei & Telescopio Nazionale Galileo, P.O. Box 565,
E-38700, S/C de La Palma, Tenerife, Spain
2 Osservatorio di Arcetri, Largo E. Fermi 5, I-50125 Firenze, Italy
3 Osservatorio Astronomico di Torino, I-10025 Pino Torinese, Italy

We report complete near-infrared (0.9-2.4 m) spectral observations of
trans-neptunian objects (TNOs) 2000 EB173 and 2000 WR106 collected using the
new Near Infrared Camera Spectrometer (NICS) attached to the 3.56m
Telescopio Nazionale Galileo (TNG). Both spectra are very red and with a
quite strong and broad drop extending throughout the K band. However, while
2000 EB173 does not show any evidence of narrow absorption features, the
spectrum of 2000 WR106 has quite deep water ice absorption at 1.5 and 2.0 m.
Moreover, the latter object is significantly less red than the former
indicating, therefore, that the surface of 2000 WR106 is ``cleaner'' (i.e.
less processed by particle irradiation) than that of 2000 EB173.

To appear in: Astronomy & Astrophysics
For preprints, contact
or on the web at

Analysis of Trans-Neptunian and Centaur Colours: Continuous Trend or

M.A. Barucci1, M. Fulchignoni1, M. Birlan1, A. Doressoundiram1,
J. Romon1, and H. Boehnhardt2
1 Observatoire de Paris, DESPA, 5, Place Jules Janssens, F-92190 Meudon,
2 ESO, Alonso de Cordova 3107, Santiago de Chile, Chile

We report the results of the first statistical analysis of colours (B-V,
V-R, V-I, and V-J) of the Trans-Neptunian and Centaur populations. Using the
same statistical techniques applied to define the current asteroid taxonomy,
we find a continuous spread of the objects between neutral colour to very
red. Pushing further the analysis, the TNOs may be split into four groups.
The differences in colour content are interpreted as a consequence of the
TNOs evolution (i.e. collisional history, space weathering, ...)

Published in: Astronomy and Astrophysics, 371, 1150 (2001 May)
For preprints, contact

Colors and Spectra of Kuiper Belt Objects
David Jewitt1 and Jane Luu2
1 Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, Hawaii 96822, USA
2 Sterrewacht Leiden, Postbus 9513, 2300RA Leiden, The Netherlands

We present new measurements of the optical colors of Kuiper Belt Objects,
principally from the Keck 10-m telescope. The measurements confirm the
existence of a wide spread in the B-V, V-R, and R-I color indices (Luu and
Jewitt 1996). Relative to the Sun, the Kuiper Belt Objects exhibit reflected
colors from nearly neutral to very red. The optical and optical-infrared
(V-J) color indices are mutually correlated, showing the presence of a
single reddening agent from m to m. On the other hand, we find no evidence
for linear correlations between the color and absolute magnitude (a proxy
for size), instantaneous heliocentric distance, semi-major axis, or with any
other orbital property. In this regard, the Kuiper Belt Objects differ from
the main-belt asteroids in which strong radial color gradients exist. We
find no statistically significant evidence for bimodal or other non-uniform
color distributions, either in our data, or in data previously reported to
show such evidence. The impact resurfacing hypothesis is re-examined in the
light of the new color data and is rejected as the primary cause of the
observed color dispersion. We also present new near-infrared reflection
spectra of 1993 SC, 1996 TS66, 1999 DE9 and 2000 EB173, taken at the Keck
and Subaru telescopes. These spectra, combined with others from the
published literature, provide independent evidence for compositional
diversity in the Kuiper Belt. Objects 2000 EB173, 1993 SC, and 1996 TS66 are
spectrally bland while 1999 DE9shows solid-state absorption bands.

To appear in: Astronomical Journal, in press
For preprints, contact
or on the web at

Photometric Study of Centaurs 10199 Chariklo (1997CU26) and 1999UG5
N. Peixinho1, P. Lacerda2, J.L. Ortiz3, A. Doressoundiram4,
M. Roos-Serote1, and P.J. Gutiérrez3
1 Centre for Astronomy and Astrophysics of the University of Lisbon/ Lisbon
Astronomical Observatory, Tapada da Ajuda, P-1349-018 Lisbon, Portugal
2 Leiden Observatory, the Netherlands
3 Instituto de Astrofísica de Andalucía, CSIC, Granada, Spain
4 Paris-Meudon Observatory, France

We present the results of visible broad band photometry of two Centaurs,
10199 Chariklo (1997CU26) and 1999UG5, from data obtained at the 1.52 meter
telescope of the National Astronomical Observatory at Calar Alto, Spain,
during 2 separate runs in April 1999 and February 2000 and at the 1.5 meter
telescope of the Sierra Nevada Observatory, Spain, in March of 1999.

For Chariklo, the absolute magnitudes determined from the February 2000 data
are found to be higher by about 0.27 magnitudes than the average in the 1999
run. This may indicate long period rotational variability and possibly a
Gparameter higher than the assumed value of 0.15. From the best sampled
R-lightcurve obtained in the February 2000 run, no short term rotational
variability was found. The V-R colours for this object in all runs are
similar to previously published values. For 1999UG5, colours were found to
be very red: ,  and . These results place this object in the group of the
reddest known bodies in the Solar System. HR and HV are found to be  and
respectively, and its diameter is estimated to be on the order of  km.

Published in: Astronomy and Astrophysics, 371, 753 (2001 May)
For preprints, contact

The Rotation Axis of the Centaur 5145 Pholus
Tony L. Farnham1
1 Department of Astronomy, University of Texas, Austin, TX 78712, USA

We present observations of the Centaur 5145 Pholus from 2000 January to 2000
August. A rotational lightcurve was assembled from both Vand R measurements,
confirming previous period determinations of 0.416 day but exhibiting an
amplitude over twice as high as previously measured. This lightcurve was
then used in conjunction with previously published lightcurves to solve for
a north pole position of ,  (prograde rotation) and a sidereal period of
0.41592560.0000016 day. As part of this analysis, the axial ratios of Pholus
were found to be a/b=1.8 and b/c=1.0. Color analyses of the data give an
average V-R color of 0.710.03, which is slightly lower than the 0.75-0.84
range previously seen. This difference, combined with the fact that we see
color variations as a function of rotation, suggest that Pholus' northern
hemisphere contains bluer features than are seen in its southern hemisphere.

To appear in: Icarus

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Short Term Variability of Centaur 1999 UG5
P.J. Gutiérrez1, J.L. Ortiz1, E. Alexandrino2,
M. Roos-Serote2, and A. Doressoundiram3
1 Instituto de Astrofísica de Andalucía. Aptd 3004, 18080 Granada. Spain
2 Lisbon Astronomical Observatory. Tapada da Ajuda, 1349-018 Lisbon,
3 Paris-Meudon Observatory, France

A lightcurve of Centaur 1999 UG5 from R-band CCD images taken at the Calar
Alto 1.52 m and La Palma 3.5 m TNG telescopes is presented. The lightcurve
shows noticeable changes in brightness. Small activity outbursts do not
appear to be the cause of the brightness changes because no coma was
detected after coadding all the images. Thus, the changes in brightness are
interpreted as being caused by rotational variability. A periodogram
analysis of the lightcurve reveals significant peaks from 13.0 h to 13.8 h,
with a confidence level exceeding 99.9%. The maximum spectral power
corresponds to 13.25 h. The overall shape of the lightcurve can be explained
by an irregular object rotating once per 26.5 h, but other possibilities
exist. Assuming an ellipsoid shape for the rotating body, the  mag amplitude
of the lightcurve implies a minimum axial ratio of 1.25. The mean absolute
magnitude in V band was found to be  assuming a typical phase parameter
G=0.15. This implies a diameter of 55.3 km for the object, provided that a
typical albedo of 0.04 is assumed. The colours of 1999 UG5were found to be ,
, and .

Published in: Astronomy and Astrophysics, 371, L1 (2001 May)
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Search for CO Gas in Pluto, Centaurs and Kuiper Belt Objects
at Radio Wavelengths
D. Bockelée-Morvan1, E. Lellouch1, N. Biver1,
G. Paubert2, J. Bauer3, P. Colom1, and D.C. Lis4
1 Observatoire de Paris, 5 place Jules Janssen, F-92195, Meudon Cedex,
2 Instituto de Radioastronomía Millimétrica, Avenida Divina Pastora 7,
Núcleo Central, 18012 Granada, Spain
3 Institute for Astronomy, University of Hawaii, 2680 Woodlawn Dr.,
Honolulu, HI 96822, USA
4 Division of Physics, Mathematics and Astronomy, California Institute of
Technology, MS 320-47, Pasadena, CA 91125, USA

We have searched for several rotational lines of CO in the Pluto-Charon
system, Centaurs (Chiron, Pholus, Nessus, Asbolus, Chariklo and 1998 SG35)
and Kuiper Belt objects (1994 TB, 1996 TL66, 1996 TO66, 1996 TP66 and 1998
WH4). The observations were performed with the 30 m telescope of the
Institut de Radioastronomie Millimétrique for Pluto/Charon, and with the
James Clerk Maxwell Telescope and Caltech Submillimeter Observatory for
Centaurs and Kuiper Belt objects. A tentative 4.5- J(2-1) CO line is present
in the Pluto/Charon spectrum, which requires further confirmation. Assuming
that Charon does not contribute to the CO emission, an upper limit of 1.2%
and 7% is obtained for the CO/N2 mixing ratio in Pluto's atmosphere, using
the atmospheric thermal structure derived from the Stansberry et al. (1994,
Icarus 111, 503) and Strobel et al. (1996, Icarus 120, 266) models,
respectively. These upper limits are more constraining (by more than a
factor of 6) than the upper limits reported by Young et al. (2001, Icarus,
in press) from near-IR spectroscopy. None of the Centaurs or Kuiper Belt
objects (KBO) were detected in CO. The CO production rate upper limit
obtained for Chiron (3-5  mol s-1) over 1998-2000 years is a factor of 10
lower than the CO production rate derived from the marginal CO detection
obtained in June 1995 by Womack & Stern (1999, Astron. Vestnik 33, 216),
using same modelling of CO emission. Upper limits obtained for other
Centaurs are typically  1028 mol s-1

To appear in: Astronomy & Astrophysics
For preprints, contact

Discovery of Water Vapor Around IRC+10216 as Evidence for Comets Orbiting
Another Star
Gary J. Melnick1, David A. Neufeld2, K.E. Saavik Ford2,
David J. Hollenbach3, and Matthew L.N. Ashby1

1 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge,
Massachusetts 02138, USA
2 Department of Physics & Astronomy, The Johns Hopkins University, 3400 N.
Charles Street, Baltimore, Maryland 21218, USA
3 NASA/Ames Research Center, Moffett Field, California 94035, USA

Since 1995, planets with masses comparable to that of Jupiter have been
discovered around approximately 60 stars. These planets have not been seen
directly, but their presence has been inferred from the small reflex motions
that they gravitationally induce on the star they orbit; these motions
result in small periodic wavelength shifts in the stellar spectrum. The
presence of analogues of the smaller bodies in our Solar System cannot,
however, be determined using this technique, because the induced reflex
motions are too small-so an alternative approach is needed. Here we report
the observation of circumstellar water vapour around the ageing carbon star
IRC+10216; water is not expected in measurable quantities around such a
star. The only plausible explanation for this water is that the recent
evolution of IRC+10216, which has been accompanied by a prodigious increase
in its luminosity, is causing the vaporization of a collection of orbiting
icy bodies-a process considered in an earlier theoretical study.

Published in: Nature, 412, 160 (2001 July 12)
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