The idea of
an additional large planet orbiting far outside our solar system has been
around for a long time. It may well
exist. It may even be a brown dwarf that
we simply can not see.
However, I
think that a circular orbit is unlikely.
Sitchen predicted his plane X to have a long elliptical orbit that
brought the planet into the inner solar system.
We have even
better evidence that we orbit through the Sirius cluster every 200,000 years or
so. Such an event could well look like
planet orbiting us.
It would
likely produce a distorted orbit for a distant solar planet.
Meanwhile, we
have learned that disturbing a comet is not an easy trick without a big object
and that the presence of comets is confirmation of perturbation. Something(s) is out there. Yet perturbed orbits could still be artifacts
of the pass through Sirius over a 100 thousand years ago.
There may be
room for everything, but if we give credence to any of the material, I find the
pass through Sirius satisfying because it gives us a large hot object that
could meet the requirements of purported eye witness reports that Sitchen
reported.
There is
presently no obvious evidence of any recent comet disturbances which suggests
that any hypothetical planet is a long ways away for now.
Massive dark object 'lurking on edge of
solar system hurling comets at Earth'
Last updated at 8:50 AM on 8th December 2010
A
massive dark object may be lurking on the edge of our solar system, according
to scientists.
Most
comets that fly into the inner solar system seem to come from the outer region
of the Oort cloud - a region of icy dust and debris left over from the
birth of the solar system.
The
cloud starts from a point about 93 billion miles from the Sun and stretches for
around three light years and contains billions of comets, most of them small
and hidden.
A Nasa
graphic which illustrates how the Oort Cloud surrounds our solar system.
Scientists believe that an object with a huge mass may be pushing comets
towards Earth from the cloud
Now new
calculations suggest a large object that is up to four times as big as Jupiter
could be responsible for sending them in our direction.
The
scientists have analysed the comets in the Oort cloud and deduced that 25
per-cent of them would need a nudge by a body of at least Jupiter size before
they changed orbit.
Astrophysicists
John Matese and Daniel Whitmire at the University of Louisiana
They
believe that our solar system has a hidden 'companion' that has so far remained
undetected.
The
scientists have been studying the cloud using WISE, Nasa's infra-red space
telescope that is capable of detecting dark objects.
Matese
said: 'I think this whole issue will be resolved in the next five to 10 years,
because there’s surveys coming on line that will dwarf the comet sample we have
today.
'Whether
these types of asymmetries in the directions that comets are coming from
actually do exist or not will definitely be hammered out by those surveys,'
Matese added. 'We anticipate that WISE is going to falsify or verify our
conjecture.'
About
3,200 long-period comets are known, one of the most famous being Hale-Bopp
which was visible to even the naked eye during 1996 and 1997.
Halley's
Comet, which reappears about every 75 years, is a 'short-period' comet from a
different part of the Solar System called the Kuiper Belt.
A large
planet that is in orbit outside the solar system may be pushing comets towards
Earth
If it
exists the new planet is so freezing cold it is difficult to spot, researchers
said.
It could
be found up to 30,000 astronomical units from the sun. One AU is the distance
between the Earth and the sun, about 93 million miles.
Scientists
have already proposed that a hidden star, which they call 'Nemesis,' might
exist a light-year or so away from our sun.
They
suggest that during its orbit it would regularly enter the Oort cloud, jostling
the orbits of many comets there and causing some to fall toward Earth.
These
occasional comet showers could be why the mass extinctions on Earth are so
regular, some scientists believe.
The
research appeared in the online edition of the journal Icarus.
'Most
planetary scientists would not be surprised if the largest undiscovered
companion was Neptune-sized or smaller, but a Jupiter-mass object would be a
surprise,' Matese told SPACE.com
'If the
conjecture is indeed true, the important implications would relate to how it
got there — touching on the early solar environment — and how it might have
affected the subsequent distributions of comets and, to a lesser extent, the
known planets.'
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