[Oct.07.99] A Mystery Revolves Around The Sun
White Male Conservative
http://www.msnbc.com/news/320182.asp
Researchers suggest that huge unseen object orbits on
fringe of solar system...
This diagram, <http://www.msnbc.com/news/457711.jpg>
produced by NASA's Jet Propulsion Laboratory, shows
the nine planets as a small inset within the much
larger Oort Cloud, extending trillions of miles out
from the sun. The hypothetical planet or brown dwarf
would lie about halfway out from the center of the cloud.
http://www.msnbc.com/news/320182.asp
By Alan Boyle
MSNBC
[October 07, 1999] --- Two teams of researchers have
proposed the existence of an unseen planet or a failed
star circling the sun at a distance of more than
2 trillion miles, far beyond the orbits of the nine
known planets. The theory, which seeks to explain
patterns in comets' paths, has been put forward in
research accepted for publication in two separate
journals.
SPECULATION ABOUT the existence of unseen
celestial companions dates back far before the discovery
of Pluto in 1929 --- and even figures in more recent fringe
phenomena such as the 1997 "Heaven's Gate" tragedy and
talk of a new "Planet X." This latest hypothesis, however,
is aimed at answering nagging scientific questions about how
particular types of comets make their way into the inner
solar system.
Some comets, like Halley's Comet, follow relatively
short-period orbits --- circling the sun in less than two
hundred years. These comets are thought to originate in the
Kuiper Belt, a disk of cosmic debris that lies beyond
Neptune's orbit.
The best way to think of the distances involved is in
terms of Astronomical Units. One AU is the distance from
Earth to the sun (93 million miles or 149.6 million
kilometers). Pluto, the most distant of the planets, is at
39 AU. The Kuiper Belt extends from 30 AU to perhaps
1,000 AU.
Even further out is the Oort Cloud, a spherical haze of
comets surrounding the solar system at distances between
10,000 AU and more than 50,000 AU. That's where
long-period comets such as Hale-Bopp are thought to come
from. For some time, astronomers have noticed that the
directional patterns of these comets are not completely
random. And after years of study, some researchers are
reporting that the patterns hint at something big out there
perturbing the cometary paths.
WHAT COULD IT BE?
http://www.msnbc.com/news/320182.asp
No telescope has yet detected this object. But on the
basis of its gravitational effect, John B. Murray, a planetary
scientist at Britain's Open University, speculates that the
object could be a planet larger than Jupiter, the biggest of
the solar system's known planets. Murray puts the object's
orbit at 32,000 AU, or 2.98 trillion miles from the sun. His
proposal appears in the Oct. 11 issue of the Monthly
Notices of the Royal Astronomical Society.
Meanwhile, researchers at the University of Louisiana
at Lafayette say the object could be a planet or brown
dwarf --- that is, a dark, failed star --- roughly three times
the size of Jupiter and orbiting at 25,000 AU. The
researchers, led by physicist John Matese, say their paper is
to be published by the journal Icarus.
Both studies acknowledge that other factors could
influence the pattern seen in long-period comets: for
example, the Milky Way's gravitational tidal effects. But the
Louisiana researchers say the cometary patterns are best
explained by the existence of "a perturber, acting in concert
with the galactic tide."
Matese said the proposed object should make one
orbit around the sun every 4 million to 5 million years.
Murray said the object he had in mind would make one
orbit every 6 million years, circling the sun in a direction
counter to that followed by the nine traditional planets.
The two researchers said they were familiar with each
other's work but hadn't taken a close look at each other's
studies. They acknowledged that their estimates for the
mass and orbit of a mysterious object were similar, but
couldn't say whether they were talking about the same
object.
MORE QUESTIONS
How could such a massive object exist so far from the
sun? The researchers say a planet or dark star could have
coalesced during the formation of the solar system billions of
years ago, but more probably would be a passing celestial
body that was captured by the sun's subtle gravitational
pull.
Another question: Why hasn't such an object been
seen? Murray says that even a Jupiter-scale planet could
not be observed at the immense distances involved. Matese
and his colleagues say that their hypothetical brown dwarf
wouldn't have been detected even by the Infrared
Astronomical Satellite, which surveyed the heavens in 1983
--- but that the yet-to-be-launched Space Infrared
Telescope Facility just might be able to pick it up.
All this may sound like science fiction, but an expert in
the field notes that the hypothesis has been a subject of
serious speculation for years.
"We've all wondered whether there was something out
there," said Brian Marsden, who heads the International
Astronomical Union's Central Bureau for Astronomical
Telegrams as well as the Minor Planet Center at the
Smithsonian Astrophysical Observatory.
However, Marsden also expressed some skepticism
about the evidence behind the latest research.
"I'm not convinced it is not due to chance," he told
MSNBC in an e-mail message. "In any case, the data may
not be as good as one would like."
SPECULATIVE SCENARIO
If the research holds up, it could open the door for
renewed speculation on even spookier questions: Some
theorists have proposed that the gravitational effect of a
massive unseen object in a distant orbit --- nicknamed
"Nemesis" or the "Death Star" --- could set off periodic
cometary storms, which would increase the chances of a
catastrophic impact with Earth. Indeed, physicist Daniel
Whitmire, a colleague of Matese's who is a co-author of the
new research, laid out just such a scenario in 1985 to
explain mass extinctions on Earth, such as the demise of the
dinosaurs.
Matese also speculated back then about such an effect,
but he emphasized that the newly detected object didn't fit
the doomsday profile.
"This object is not a Nemesis," he told MSNBC. "It
does not create comet storms."
He said his proposed object appeared to have an
influence on about 25 percent of the long-period comets
coming in from the Oort Cloud.
Matese noted that theories proposing a
correlation between extinctions on Earth and
celestial orbits had fallen out of scientific favor in
recent years. But he said there could be a "much
more gentle" effect thatlinks periodic changes in
cratering to the solar system's oscillating motion through the
galactic plane.
As the solar system moves around the Milky Way's
center, it bobs slowly up and down through the galactic
disk, Matese explained. The gravitational effects could
cause changes in the number of comets sent into the inner
solar system, he said.
"We don't know the precise period of that motion"
through the plane of the galaxy, he said. "If we discover that
it's closer to a 35-million-year period, then a case can be
made that it causes periodic changes in cratering."
http://www.msnbc.com/news/320182.asp
Discuss the theories on the Space News Bulletin Board ...
http://www.msnbc.com/bbs/space.asp
... And discuss the cosmic implications on the Mysteries BBS
http://bbs.msnbc.com/bbs/msnbc-mysteries/index.asp
The Nine Planets: Theoretical Planets
http://seds.lpl.arizona.edu/billa/tnp/hypo.html
The Nemesis Hypothesis
http://www2.aae.uiuc.edu/~mjmorgan/nemesis.html
University of Louisiana at Lafayette: John Matese
http://www.ucs.usl.edu/~jjm9638/matese.html
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Doktor Caligari
The Nemesis Hypothesis
by Mike Morgan http://www2.aae.uiuc.edu/~mjmorgan/nemesis.html
I. Introduction: The theory of our Sun's binary star,
the Death Star
1) Mass Extinction on Earth: Fossil Records
2) Oort Cloud
3) Nemesis Hypothesis
II. Nemesis: Proposed in 1985 by Whitmire & Matese to fit mass
extinction evidence
1) Orbit
2) Luminosity
3) Results
III. Problems: The theory isn't without flaws
1) No direct observation of Nemesis
2) Computer Models Don't Support
3) Scientists Disagree on Periodic Extinction
IV. Alternate Theories: There are other forms of mass extinction...
1) Planet X
2) Galactic Plane Oscillations
3) Terrestrial Reasons: Change in Earth's Magnetic Field,
Falling Sea Level
V. Application to Extraterrestrial Life
1) The Influence of Comets on Life
2) Common to Other Star/Planetary Systems?
james...@my-deja.com
Doktor Caligari <Cali...@zoomkino.de> wrote:
> White Male Conservative wrote:
> >
> > A mystery revolves around the sun
> > http://www.msnbc.com/news/320182.asp
> >
> > Researchers suggest that huge unseen object orbits on
> > fringe of solar system...
> > This diagram, <http://www.msnbc.com/news/457711.jpg>
> > produced by NASA's Jet Propulsion Laboratory, shows
> > the nine planets as a small inset within the much
> > larger Oort Cloud, extending trillions of miles out
> > from the sun. The hypothetical planet or brown dwarf
> > would lie about halfway out from the center of the cloud.
> > http://www.msnbc.com/news/320182.asp
> >
Another interesting mass extinction model that is being
looked at deals with the proper motion of the stars.
If we look at the data on the star system Gliese 710,
pay attention to the radial velocity, then look at it's
traverse velocity. Combine that with it's parallax
and you'll see that it's the nearest star in the galaxy
heading in our direction. Currently 63 light years
out, it is expected to close within a light year of the
Sun in approx. 1 million years. This article you
reference states that the Oort cloud may extend as far
out as 50,000 AUs. Although Gliese 710 is a lower
mass object, it could well have an Oort cloud of it's
own. When we consider that a ly is ~63,272 AUs, it
would not be altogether unreasonable to suppose that
there could be some fireworks in our future as the
clouds cross and the gravitational influence of these
two stars stir things up a bit.
I'll refrain from making any predictions ;)
Jim Smith
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