PLEASE NOTE:
*
CCNet, 057/2000 - 12 May 2000
-----------------------------
"This has been exciting to me,
because I've always been interested
in classics in astronomy. I have nothing
but the greatest respect
for those earlier astronomers. They
actually had to look through
the telescope lens to find their
objects. They didn't have
computers or CCDs. For me, when I first
saw it [719 Albert], this
was another unusual asteroid. It was
Gareth Williams of the Minor
Planet Center who made the
identification. I owe him several
beers."
-- Jeff
Larsen, Spacewatch
(1) LONG-LOST ASTEROID 719 ALBERT IS FOUND
Andrew Yee <ayee@nova.astro.utoronto.ca>
(2) IMPACT! CHANDRA IMAGES A YOUNG SUPERNOVA BLAST WAVE
NASANews@hq.nasa.gov
(3) ROYAL ASTRONOMICAL SOCIETY HONOURS PATRICK MOORE
Jacqueline Mitton <aco01@dial.pipex.com>
(4) U.S. OFFICIAL SAYS MISSILE SHIELD INEVITABLE
SpaceDaily, 11 May 2000
(5) EL NINO-LIKE CLIMATE PATTERNS DURING THE ICE AGE
University of Massachusetts at Amherst
(6) ASTEROID ALBERT WON'T COME ‘CLOSE’
Konrad Ebisch <kebisch@zycor.lgc.com>
(7) SOLAR ACTIVITY RATHER VOLATILE
Michael Martin-Smith <martin@miff.demon.co.uk>
==============
(1) LONG-LOST ASTEROID 719 ALBERT IS FOUND
From Andrew Yee <ayee@nova.astro.utoronto.ca>
News Services
University of Arizona
*** EDITORS NOTE: A joint news release from the Minor Planet
Center at
the Smithsonian Astrophysical Observatory and the Spacewatch
Project of
the Lunar and Planetary Laboratory at the University of Arizona
is
posted on the web site: CFA, http://cfa-www.harvard.edu/cfa/ps/pressinfo/Albert.html
UA contacts:
Jeff Larsen
jlaresen@lpl.arizona.edu
520-621-2824 (campus), or call him today between 7 p.m. and 4
a.m. MST
at the Spacewatch telescope (520-318-8693)
Bob McMillan
bob@lpl.arizona.edu
520-621-6968
Jim Scotti
jscotti@lpl.arizona.edu
520-621-2717
Tom Gehrels
tgehrels@lpl.arizona.edu
520-621-6970
Joe Montani
jmontani@lpl.arizona.edu
520-621-6956
(Montani can take calls in Spanish).
MPC contacts:
Gareth V. Williams
gwilliams@cfa.harvard.edu
617-495-7444
Brian G. Marsden
bmarsden@cfa.harvard.edu
617-495-7244
10 May 2000
Long-lost asteroid 719 Albert is found -- whereabouts unknown
since 1911
By Lori Stiles
TUCSON -- University of Arizona Spacewatch astronomers at Kitt
Peak,
Ariz., have rediscovered the last "lost" numbered minor
planet, the
Minor Planet Center located at the Smithsonian Astrophysical
Observatory in Cambridge, Mass., demonstrated yesterday (May 9).
Until this month, asteroid 719 Albert has long eluded
astronomers. It
was last seen by direct observation in 1911, the year it was
discovered
by astronomer Johann Palisa (1848-1925) at the Imperial
Observatory in
Vienna, a world-class observatory of the pre-World War I
Austro-Hungarian empire.
Palisa was using the observatory's prize 68-cm (27-inch)
telescope when
he discovered the new minor planet on Oct. 3, 1911. He observed
it
again on Oct. 4, as did an astronomer at Copenhagen Observatory,
which
had been notified of Palisa's find.
That was the last direct observation anyone had of 719 Albert,
named
for a baron who had donated generously to the Vienna Observatory.
Until
last week.
Jeff A. Larsen first detected asteroid 2000 JW8 -- now known to
be 719
Albert -- with the .9-meter (36-inch) Spacewatch telescope early
in his
May 1 observing run. Larsen, a principal research specialist who
joined
Spacewatch three years ago, has dedicated most of his time to
writing
computer software for the telescope.
"This object was very faint, almost at the limits of what
Spacewatch
can do, and it wasn't moving all that fast," Larsen said.
"But it
caught my eye because it was moving differently from its
neighbors. It
moved like a near-Earth object."
Spacewatch director Robert S. McMillan and Spacewatch astronomer
James
V. Scotti observed the asteroid again on May 3 and May 6. They
confirmed that the asteroid, officially named 2000 JW8, was an
Earth-approacher. Yesterday, May 9, Michael Hicks and Ron Fevig
of the
UA Lunar and Planetary Lab observed the asteroid once more, this
time
using the 2.1-meter (84-inch) Kitt Peak reflector.
Gareth V. Williams, associate director of the Minor Planet Center
(MPC), did the orbital calculations that showed 2000 JW8 is
long-lost
719 Albert. MPC Director Brian Marsden reviewed the calculations
and
quickly concurred that, after 89 years, asteroid Albert had been
rediscovered.
Astronomers now know the asteroid's orbit precisely. They know
that
most of the time, asteroid 719 Albert is 300 million miles or
more from
the sun, and that it makes a complete orbit around the sun every
4.28
years. It makes its closest swings by Earth every 30 years -- in
1911,
1941, 1971 and 2001.
"It's never going to hit Earth," McMillan said. The
close approaches
are between about 19 million miles and 29 million miles from
Earth, or
never closer than roughly a fifth the distance from the Earth to
the
sun.
Astronomers plan to learn more about the asteroid when it comes
within
27 million miles of Earth on Sept. 5, 2001.
Scientists don't know for sure how large the asteroid is because
they
don't know how much light is reflected by the asteroid's surface
material, McMillan added. Given its absolute magnitude, or
absolute
brightness, astronomers estimate that the asteroid is between 2
kilometers (1.24 miles) and 4 kilometers (2.5 miles) in diameter.
Astronomers have remained intrigued by the asteroid "partly
because of
the intellectual challenge of finding an object that has been
lost for
so long and comes close to Earth only once every 30 years,"
McMillan
said.
The recovery has been "satisfying for Spacewatch, too,
because we found
the object when it was quite faint, more than a year before its
closest
approach to Earth," McMillan said. Spacewatch covers a
relatively small
area of sky, but it sees very faint objects farther out into the
solar
system than do other such surveys.
"Other asteroid surveys would have found this eventually,
but finding
it now gives astronomers time to apply for telescope time on
larger
telescopes for detailed observations of the asteroid,"
McMillan said.
"This has been exciting to me, because I've always been
interested in
classics in astronomy," Larsen said. "I have nothing
but the greatest
respect for those earlier astronomers. They actually had to look
through the telescope lens to find their objects. They didn't
have
computers or CCDs.
"For me, when I first saw it, this was another unusual
asteroid," he
said. "It was Gareth Williams of the Minor Planet Center who
made the
identification. I owe him several beers."
UA Professor Tom Gehrels and McMillan founded the Spacewatch
Project in
1980. It is a survey of the whole solar system, from the vicinity
of
Earth's orbit all the way out to beyond Neptune's orbit. The
primary
goal is to explore the various populations of small objects in
the
solar system and to study the statistics of asteroids and comets
to
better understand the dynamical evolution of the solar system.
Spacewatch also finds potential targets for space missions,
provides
astrometric support for spacecraft mission planning, and finds
objects
that might present a hazard to the Earth. More information about
Spacewatch can be found on the web site: Spacewatch,
http://www.lpl.arizona.edu/spacewatch/
.
===============
(2) IMPACT! CHANDRA IMAGES A YOUNG SUPERNOVA BLAST WAVE
From NASANews@hq.nasa.gov
Dolores Beasley
Headquarters, Washington,
DC
May 11, 2000
(Phone: 202/358-1753)
Steve Roy
Marshall Space Flight Center, Huntsville, AL
(Phone: 256/544-6535)
Dr. Wallace Tucker
Harvard-Smithsonian Center for Astrophysics, Cambridge, MA
(Phone: 617/496-7998)
RELEASE: 00-77
IMPACT! CHANDRA IMAGES A YOUNG SUPERNOVA BLAST WAVE
Two images made by NASA's Chandra X-ray
Observatory,
one in October 1999, the other in January 2000, show for
the first time the full impact of the actual blast wave
from Supernova 1987A (SN1987A). The observations are the
first time that X-rays from a shock wave have been imaged
at such an early stage of a supernova explosion..
Recent observations of SN 1987A with the
Hubble Space
Telescope revealed gradually brightening hot spots from a
ring of matter ejected by the star thousands of years
before it exploded. Chandra's X-ray images show the cause
for this brightening ring. A shock wave is smashing into
portions of the ring at a speed of 10 million miles per
hour (4,500 kilometers per second). The gas behind the
shock wave has a temperature of about ten million degrees
Celsius, and is visible only with an X-ray telescope.
"With Hubble we heard the whistle
from the oncoming
train," said David Burrows of Pennsylvania State
University, University Park, the leader of the team of
scientists involved in analyzing the Chandra data on SN
1987A. "Now, with Chandra, we can see the train."
The X-ray observations appear to confirm
the general
outlines of a model developed by team member Richard McCray
of the University of Colorado, Boulder, and others, which
holds that a shock wave has been moving out ahead of the
debris expelled by the explosion. As this shock wave
collides with material outside the ring, it heats it to
millions of degrees. "We are witnessing the birth of a
supernova remnant for the first time," McCray said.
The Chandra images clearly show the
previously unseen,
shock-heated matter just inside the optical ring.
Comparison with observations made with Chandra in October
and January, and with Hubble in February 2000, show that
the X-ray emission peaks close to the newly discovered
optical hot spots, and indicate that the wave is beginning
to hit the ring.
In the next few years, the shock wave
will light up
still more material in the ring, and an inward moving, or
reverse, shock wave will heat the material ejected in the
explosion itself. "The supernova is digging up its own
past," said McCray.
The observations were made on October 6,
1999, using
the Advanced CCD Imaging Spectrometer (ACIS) and the High
Energy Transmission Grating, and again on January 17, 2000,
using ACIS. Other members of the team were Eli Michael of
the University of Colorado; Dr. Una Hwang, Dr. Steven Holt
and Dr. Rob Petre of NASA's Goddard Space Flight Center in
Greenbelt, MD; and Professors Gordon Garmire and John
Nousek of Pennsylvania State University. The results will
be published in an upcoming issue of the Astrophysical
Journal.
The ACIS instrument was built for NASA
by the
Massachusetts Institute of Technology, Cambridge, and
Pennsylvania State University. The High Energy
Transmission Grating was built by the Massachusetts
Institute of Technology. NASA's Marshall Space Flight
Center in Huntsville, AL, manages the Chandra program. TRW,
Inc., Redondo Beach, CA, is the prime contractor for the
spacecraft. The Smithsonian's Chandra X-ray Center controls
science and flight operations from Cambridge, MA.
Images to illustrate this release and more information
on Chandra's progress can be found on the Internet at:
http://chandra.harvard.edu
and http://chandra.nasa.gov
===============
(3) ROYAL ASTRONOMICAL SOCIETY HONOURS PATRICK MOORE
From Jacqueline Mitton <aco01@dial.pipex.com>
ROYAL ASTRONOMICAL SOCIETY
PRESS NOTICE
Date: 12 May 2000
For immediate release
Ref. PN 00/10
ISSUED BY:
Dr Jacqueline Mitton
RAS Press Officer
Office & home phone: Cambridge ((0)1223) 564914
Mobile: 07770 386133
FAX: Cambridge ((0)1223) 572892
E-mail: jmitton@dial.pipex.com
RAS web: www.ras.org.uk/press/press.htm
ROYAL ASTRONOMICAL SOCIETY HONOURS PATRICK MOORE
The Council of the Royal Astronomical Society announced today
that it
is to make a special Millennial Award to Patrick Moore in
recognition
of his unique contribution to astronomy. The award will take the
form
of an inscribed commemorative gift, which will be presented at a
future
meeting of the Society.
Professor David Williams, outgoing President of the RAS said,
"Patrick
Moore has been the foremost popularizer of astronomy in the UK
for more
than 40 years, and has served as an exemplary ambassador for our
science to the British public and around the world. He was
responsible
for first sparking the interest in many of us who went on to
become
astronomers and he has always encouraged young people, giving
generously of his time and expertise. The Society was keen to
show its
admiration of Patrick's exceptional achievements in a personal
and
special way."
Patrick Moore has presented 'The Sky at Night' on BBC television
every
month since 1957, and is the author of around 70 books. He was
awarded
the Royal Astronomical Society's Jackson-Gwilt medal in 1977, and
was
made a CBE in 1988.
=================
(4) U.S. OFFICIAL SAYS MISSILE SHIELD INEVITABLE
From SpaceDaily, 11 May 2000
http://www.spacedaily.com/news/bmdo-00x.html
State Department Official Says Missile Shield Inevitable
by Matthew Lee
Washington (AFP) May 11, 2000 - A senior State Department
official said
Thursday that eventual deployment of a proposed anti-missile
defense
shield is almost inevitable despite vehement opposition from
China,
Russia and some US allies in Europe.
Even if President Bill Clinton chooses not to proceed with
national
missile defense (NMD) -- a decision he will make later this year
-- the
United States will be forced to respond to emerging missile
threats at
some point, the official said.
Intercontinental ballistic missile (ICBM) dangers from so-called
"rogue
states" -- including North Korea in the short- to
medium-term and Iran
in the longer term -- are real and no amount of protest from
China,
Russia or others will change that, he said.
"I would project that this issue isn't going to go
away," the official,
speaking on condition of anonymity, told reporters, stressing
that US
lobbying of Russia to modify the 1972 Anti-Ballistic Missile
treaty to
allow for NMD would only intensify.
"We are proceeding on the basis of the threat assessments
that the
intelligence community has laid out and developing a program that
has
been fleshed out in some detail that would respond to the North
Korean
capability at the earliest possible date."
"There is a broad consensus in the United States across the
political
spectrum that the United States needs to respond to this emerging
new
kind of ICBM threat ...
"And I think it will be important under any administration
to update
the ABM treaty to make sure that it not only preserves its
original
purposes but accounts for changes in the international
environment that
weren't contemplated when the treaty was negotiated nearly 30
years
ago."
Clinton is to travel to Moscow next month and the top item on his
agenda will be trying to convince his Russian counterpart,
Vladimir
Putin, and skeptical law and policy makers there that revising
the ABM
treaty is the only practical course to take in the new
atmosphere.
The treaty, signed by the United States and the former Soviet
Union and
aimed at preserving deterrence as the chief method of avoiding
nuclear
war by limiting defenses, forbids large-scale systems capable of
shooting down incoming missiles.
Russia is opposed to amending the pact, seeing NMD as a direct
threat
to its security and has rejected suggested modifications
submitted to it
earlier this year by US officials.
And a top Chinese official has warned that NMD deployment could
force
Beijing to strengthen its nuclear force as well as develop its
own
counter measures, creating a new wave of strategic weapons
proliferation.
But the US official said Russian fears were misplaced, noting
Washington's willingness to accede to a variety of
confidence-building
measures.
He hinted that even without ABM amendments, NMD could go ahead if
the
treaty were scrapped as some conservative US lawmakers have
suggested.
"What we're trying to do is avoid putting the president in a
position
where he has to choose between (NMD) that he may well conclude is
necessary for the defense of the country and the ABM
treaty," the
official said.
Chinese opposition to NMD is equally misplaced, the official,
stressing
that China was not targeted by it and maintaining that Beijing's
warning about the system forcing nuclear proliferation was not
valid.
"The likelihood is that whether or not we proceed with NMD
that China's
nuclear forces would expand in a way that could make this system
less
threatening to China," the official said.
In an interview published by the New York Times Thursday, China's
top
arms negotiator, Sha Zukang, said deployment of NMD would be
countered
by Beijing.
"We'll have to do something," he told the paper.
"How can we base our
own national security on your assurances of good will?"
He said the proposed anti-missile shield would upset the
"balance of
terror" that has kept nuclear peace up to now, and would
touch off a
global arms race and possibly a "nightmare scenario" of
weapons
proliferation.
Copyright 2000, AFP
================
(5) EL NINO-LIKE CLIMATE PATTERNS DURING THE ICE AGE
From University of Massachusetts at Amherst
11 May 2000
Contact: Elizabeth Luciano
luciano@journ.umass.edu
413-545-0444
University of Massachusetts at Amherst
El Niņo-like climate patterns occurred in New England during the
Ice
Age, University of Massachusetts researchers find
The New England region underwent El Niņo-like climate changes
during
the Ice Age, a team of researchers has found. University of
Massachusetts geoscientist Julie Brigham-Grette led the research,
along with former UMass graduate student Tammy Rittenour (now a
doctoral candidate at the University of Nebraska), and
environmental
scientist Michael Mann, now at the University of Virginia. The
findings
are detailed in the May 12 issue of Science. The project was
funded by
the National Science Foundation, National Geographic Society, and
the
University of Massachusetts.
Scientists define El Niņo as a disruption of the
ocean-atmosphere
system in the tropical Pacific, having important consequences for
weather around the globe. A weakening of the tradewinds allows
unusually warm currents in the western Pacific to flow eastward
across
the equatorial Pacific to the western coast of South America.
This
exceptionally large area of warm ocean surface waters occurs
cyclically, often causing significant changes in global weather
patterns, including those affecting the northeastern United
States. The
team's findings show a strong three-to-five-year cycle of El
Niņo
activity during the later part of the last Ice Age - the same
frequency
with which El Niņo occurs today. Researchers focused on the era
when
the Laurentide Ice Sheet was slowly receding northward across New
England, leaving Glacial Lake Hitchcock in its wake. At its peak,
the
glacial lake filled much of the Connecticut Valley, including the
area
that eventually became the UMass campus.
The report offers scientists a clearer understanding of El
Niņo's
persistence at a time when climate conditions were fundamentally
different from the climate conditions of today, according to the
team.
"El Niņo-like climate change can happen under all sorts of
conditions,
even when the Northern Hemisphere is covered with large ice
sheets,"
said Brigham-Grette. "It's not just a warm-weather
phenomenon. Knowing
this will help scientists in determining what drives El
Niņos."
"It was previously thought that El Niņos were a
warm-weather phenomenon
that began only 5,000 years ago," said Rittenour. "Our
findings have
pushed the record of El Niņo activity back to 17,500 years ago.
This is
remarkable because at that time, all of Canada and most of the
northern
United States was covered by a large ice sheet."
"This glacial evidence suggests that the El Niņo phenomenon
is even
more robust than we previously imagined," added Mann.
"This provides a
new perspective on the changes in El Niņo observed in recent
decades,
and their possible relationship with global climate change."
In September 1997, Rittenour and Brigham-Grette retrieved two
sediment
cores from the western edge of campus, at a site used for civil
engineering research. One core was 105 feet (30 meters) long; the
other
was 25 feet (7.6 meters) long. Much of Brigham-Grette's work has
focused on learning about past climate by studying sediment
archives in
Arctic coastal areas and lake beds as far-off as Siberia; in
contrast
the UMass core was taken from her professional backyard. Mann
assisted
the team by applying modern statistical methods to develop a
climate
history from these records, and analyze it for insights into the
past
behavior of El Niņo.
The team split and examined the cores before conducting
scientific
measurements on the samples. The layers of sediment offer
scientists a
very detailed record of climate variability, scientists say.
"The
thickness of the annual sediment layers in the cores tells us
about the
amount of meltwater coming off the glacier," Brigham-Grette
explained.
"The warmth of El Niņo-like events caused faster melting of
the glacier
front and perhaps a change in precipitation. This resulted in
thicker
annual layers, or varves, during those seasons." The cores
provided not
only an annual record of climate, but seasonal records as well.
The
spring and summer season contains most of the variability. The
project
enabled researchers to place the local sediment history into the
regional geological framework and in the future will allow
comparisons
with long records of climate change in the Greenland Ice Sheet.
The team's findings bolster those made by a University of
Stockholm
researcher nearly a century ago. In 1922, Ernest Antevs produced
a
4,000 year-long, regional climate record based on layered
sediments,
(which scientists call a "varved chronology"). Antevs
physically
measured hundreds of areas of exposed sediments that dated to the
glacier's retreat. Although his work is still considered by many
to be
a gold standard in geoscience, the Antevs record had some small
gaps.
The team was able to complete one major section of the Antevs
record,
based on findings from the UMass cores.
The paper represents a portion of Rittenour's master's thesis at
UMass.
For her new research in the Mississippi River Valley, Rittenour
has
just won the J. Hoover Mackin Award for 2000 given by the
Geological
Society of America's Quaternary Division. This is the highest
award
given to a geology Ph.D. candidate in the country. Brigham-Grette
won
the same award 19 years ago.
Note: Downloadable, 300-dpi images of the researchers are
available at
http://www.umass.edu/newsoffice/archive/2000/051100iceage.html
of Brigham-Grette and Rittenour
retrieving the cores are available at: www.geo.umass.edu/projects/valley/valpics.html
=============================
* LETTERS TO THE MODERATOR *
=============================
(6) ASTEROID ALBERT WON'T COME ‘CLOSE’
From Konrad Ebisch <kebisch@zycor.lgc.com>
Dear Benny,
In your latest CCNet, I read,
(1) LOST ASTEROID DISCOVERED AFTER 89 YEARS
" ... Next year (in September 2001), asteroid
Albert will make a
close approach to the Earth when it will come as
close as 0.286 AU."
I wonder if we confuse anybody by what we call a "close
approach".
0.286 AU is a close approach if "close approach" means
a good time
to point my telescope in that direction. But if "close
approach" means
I should worry about a possible impact, or plan to go out in the
yard and watch it streak across the night sky, then even 0.01 Au
is not
all that close. When Mars makes a "close approach",
0.286 AU is halfway
to Mars. Indeed, I suspect that anything beyond the Moon (0.0026
AU)
will not be considered close by many people. After all, the moon
has
been passing that close for a long time, and we have not
experienced,
nor expect to experience, an impact. Perhaps we should call 0.286
AU an
"observation opportunity" instead of a "close
approach". Some kind of
distinction between the two concepts of "close
approach" is needed.
Konrad
==============
(7) SOLAR ACTIVITY RATHER VOLATILE
From Michael Martin-Smith <martin@miff.demon.co.uk>
RE: CCNet, 10 May 2000
"... The Sun appeared nearly featureless this
weekend as the sunspot
area dropped 10 times below its average value.
Nevertheless,
scientists say Solar Max is still on the way."
The solar activity (rather like current stock market activity!)
is very
volatile over short time scales. Late April saw several extremely
active sunspot complexes, while last weekend, as the quoted piece
says,
the solar disk in white light was almost devoid of activity.
There were
3 prominences, and two striking filaments just south of the
equator near
longitude 90-100( Carrington's system)
Michael Martin-Smith
----------------------------------------
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