A NASA scientist insists a 10th planet may be orbiting
the sun even though two space probes have not been able to find
any trace of it in the dim outer reaches of the solar system.
Dr. John Anderson, a celestial mechanics investigator
with NASA's Pioneer spacecraft
project, told reporters at Ames Research Center at Moffett Field
Tuesday that if the planet exists, it travels at nearly right
angles to the plane of the orbits of the nine known planets in a
looping ellipse so elongated it only nears the sun every 700 to
Anderson, who published his ideas last year in ''The
Galaxy and the Solar System'', called his theory ''an
important contribution to the understanding of the dynamics of
the outer solar system.''
Analysis of the trajectories of the Pioneer 10 and 11
spacecraft during the past five years shows no indication of
gravitational effects that would be expected if an unknown
planet was in a normal, circular orbit beyond Uranus, but 19th
century records indicate the orbits of the outer planets were
disturbed in a subtle manner, which Anderson suspects may
have been caused by gravitational effects associated with the
explanation for an object very likely to have been there for at
least 100 years, and then disappearing, is a planet on a greatly
that's the most likely possibility if you take all the current
data. It's a good possibility and a good working hypothesis. If
it isn't Planet X, then I throw up my hands and can't say what
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Sun have a doomsday twin?
In 1846, researchers noticed that Uranus was wobbling in a way
that confounded Newton's Law of Motion. This meant
they had two options: rewrite the most time-honored of the laws
of physics, or "invent" a new planet to account for the extra
gravitational pull. Compared to Newton's reputation, an eighth
planet seemed much less massive and Neptune was discovered.
Today scientists working in the University of Louisiana have
discovered a statistical anomaly of similar proportions.
Professors John Matese, Patrick Whitman and
Daniel Whitmire have studied the orbits of comets for 20
years, and their recent findings have led to startling theories.
Intrigued by the work of two paleontologists working for the
University of Chicago, Prof Whitmire, along with NASA
colleague Dr Al Jackson, had earlier attempted to explain
the amazing discovery that six apocalyptic events, including the
extinction of the dinosaurs, have all occurred, like clockwork,
every 26 to 30 million years. To try to explain this mass
extinction cycle, they looked to the possibility that comet
showers were to blame.
The latest effort of Matese, Whitman and Whitmire
studies 82 comets from the huge cloud of comets, called the Oort Cloud, that exists around our solar system. They
took the aphelia of these comets, the points on their orbit that
are farthest from our Sun, and plotted them on a globe.
Expecting to find an even distribution, they instead found that
a particular band of sky, about one sixth the total, contained
more than one quarter of all the comets, and that about 25 per
cent of the comets coming from this cloud have anomalous paths.
So what was affecting the orbits?
They went on to theorize that
the best explanation is the existence of a previously unknown
body - that our solar system is made up of the Sun and a shadowy
partner, either a brown dwarf or a massive planet, in a wide
binary system. In effect, the solar system had two stars, the
Sun and a dark companion, spinning around each other.
Now I know what you're thinking. Surely I'd have noticed a second
Sun in the sky? But, as Prof Whitmire explained, the
process of assumption based on statistical anomalies has always
been a cornerstone of scientific discovery.
According to their
current theory, he says,
"the companion is a brown dwarf star
or massive planet of mass between two and six times the mass of
A brown dwarf is a star too small to sustain the
nuclear fusion that powers our Sun, and so is relatively cool
(surface temperature of less than 1500C) and so also very dim,
being barely hot enough to give off light.
But it gets worse. Under their original theory, called the
Nemesis theory, this small dark star, which lurks at around
90,000 times farther away than the Earth is from the Sun, may be
on an orbit that, once every 30 million years, ploughs it into
the densely packed inner cloud. Here its immense gravitational
pull would drag out several of the Oort comets and give
them the "kick" needed to send them towards the Sun on orbits
perilously close to the Earth. This explains, in the professor's
view, the ominous mass extinction cycle, due to regular periods
of increased cometary activity every 30 million years.
However, before we head for the bomb shelters, we should take
heed of the professor's words:
"As a practical matter our
models will never be generally accepted (and shouldn't be) until
the actual object is found." However stressing that they are
"sufficiently plausible to give incentives for others to look".
Today, their current paper has moved away from the Nemesis
theory and proposed, on the basis of comet orbits, a less
massive planet about three times the mass of Jupiter. None the
less, with an explanation for the mass extinction cycle yet to
be found, he has admitted that they may not be mutually
exclusive; and that there could be two dark stars, one a failed
partner to our own, and another one that is acting almost as an
alarm clock for doomsday.
Even so, he says:
"I'm still hopeful
that ultimately these might turn out to be the same object.".
"An original idea in science is often a gut instinct, but this
should not influence the development of the idea," says the
professor. "I always try to be my own worst critic".
scientific world remains intrigued but skeptical. However, the
recent bombardment of Jupiter is a reminder that if the team is
right, there may not be many around to hear them say:
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Comets Hints at Something Out There
Oct. 7 - Astronomers may have found hints of a massive, distant,
still unseen object at the edge of the solar system - perhaps a
10th planet, perhaps a failed companion star - that appears to
be shoving comets toward the inner solar system from an orbit 3
trillion miles away.
Two teams of scientists - one in England, one at University of
Louisiana at Lafayette - independently report this conclusion
based on the highly elliptical orbits of so-called “long-period
comets” that originate from an icy cloud of debris far,
far beyond Pluto.
“We were driven to this by rejecting
everything else we could think of,” says University of Louisiana
physicist Daniel Whitmire.
Clump of Comets
A couple years ago, Whitmire, along fellow physicists
John Matese and Patrick Whitman, noticed the farthest
points of the comets’ orbits didn’t appear random but bunched
together, tracing a path across the sky.
“We accidentally noticed they weren’t uniform,” Whitmire says.
First, they tried to explain the clumping from the gravitational
pull from a main disk of stars in the Milky Way stars.
ultimately didn’t work,” Whitmire says. “We’ve gone through
several other models trying to explain this.”
At around the same time, John Murray, a planetary
scientist at The Open University in Great Britain,
made a similar observation in similar comet data. “I started
puzzling what this might could be,” he says. The most obvious
but seemingly unlikely explanation would be a planet.
we’d better rule that out,” he says. But as he analyzed the
orbits, the farthest points appeared to fall on a circular
orbital path - “which is exactly what you would expect if there
was a planet out there.”
As the planet - estimated to have a mass between one and 10
Jupiter's - orbits, its gravitational wake disturbs the icy
debris of the outer solar system, causing some of it to plunge
toward the sun as comets, sort of like an elephant ambling
through a china shop. No one has yet directly observed a 10th planet, and there could still be another cause for
the cluster of comets. The University of Louisiana research will
be published in an upcoming issue of the journal Icarus.
Murray’s paper will appear in Oct. 11 issue of the Monthly
Notices of the Royal Astronomical Society.
What’s surprising is just how far out there this supposed planet
Both Murray and the University of Louisiana
physicists put the planet in an orbit about 3 trillion miles - or half a light-year
- from the sun. The nearest star is four
light-years away. To put this distance in perspective, consider
a miniaturized version of the solar system in which Earth is one
inch from the sun. On this scale, Pluto, the ninth planet would
be a bit more than a yard from the sun. The new planet, by
contrast, would be a half-mile distant.
At that great distance, the 10th planet would be
too dim to see by current telescopes, although there is some
hope that if it exists, the next generation of space-based
infrared telescopes might be able to pick it up. Murray
hypothesizes the planet may have been wandering through the
galaxy before being captured by the solar system’s gravity.
Whitmire suggests it is a “brown dwarf,” or a failed star, a
companion to the sun that was too small to light up. Although
suggestive, the findings are not conclusive. While Murray
and the Louisiana physicists agree how distant the new object
is, they trace out very different orbits.
Murray considers the
orbits of 13 comets with the most accurately known orbits; the
Louisiana team considers 82.
Too Early to Look for a Name
“It’s possibly suggestive,” comments
associate director for planetary sciences at the Harvard-Smithsonian Center for Astrophysics in
Cambridge, Mass. “I don’t want to bet on it. We’re certainly not
going to name it.”
Whitmire agrees it’s too early to say
definitely there’s something out there.
“Until it’s found, you
can never be overly confident,” he says. “We know in science you
can be fooled by statistics.” But he adds, “If I was betting,
it’s better than 50-50 odds that it’s there.”
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