Hi, my name is David Morrison,
I'm a NASA space scientist
and I'd like to talk
to you briefly
about comet Elenin.
Now this little comet
is nothing special
except that you probably know,
on the internet,
there's all kinds
of wild stories
saying that it's
going to hurt us
or it threatens us,
or you should be afraid
of Comet Elenin.
I think you'll realize that that is not true
if I take a moment to tell you what a comet is.
A comet is a member of the solar system,
a very small member,
only a mile or two across generally,
that spends most of its time far from the Sun,
in the deep freeze of outer space.
But its orbit occasionally brings it in close to the Sun.
When it gets close to the Sun
the heat out gasses, material, water vapor,
carbon dioxide, dust
and produces a huge, very tenuous cloud.
So that you can't even see the little nucleus inside.
And this leads to all sorts of misunderstandings that somehow
it's growing in size. Well,
the gas cloud is but not the comet.
There're also strange stories about it's orbit.
People say it's changing it's orbit,
it's changing it's speed,
it's changing it's direction.
Well it stays exactly on it's orbit.
But in following the orbit around the Sun
under the gravitation of the Sun
of course it's constantly changing
it's speed and direction.
It's doing just what it should do.
Now consider this little nucleus
only a mile or two across.
We've not had a good look at the nucleus of comet Elenin.
But we have sent spacecraft to comets in the past.
The biggest was comet Halley
photographed here by the European Joto spacecraft.
That's about ten miles across.
One of the smallest is called Hartley
photographed by a NASA spacecraft a year ago.
That's only a little over a mile across.
These are interesting to astronomers,
but they pose no danger to any of us.
The most strange claim,
and one that's gotten
a lot of attention
is that somehow, comet Elenin,
was responsible
for the big earthquake
in Japan last March.
There's no way a comet could cause an earthquake,
in fact there's no way any celestial object
could trigger an earthquake.
The Japan earthquake was slippage on a major fault
a boundary between plates that make up the Earth's crust.
That releases a lot of energy and this happens repeatedly
in fact that fault is one of the most active faults on Earth.
Although this earthquake was exceptionally large.
I can assure you the comet had nothing to do with it.
Some people say "Well, this isn't even a comet"
it's something massive,
a brown dwarf perhaps which would be a small star
with a hundred times the mass of Jupiter.
Well that's simply impossible.
First the very fact that it is has
this extended atmosphere and tail,
shows that it has low gravity.
If it were a massive high gravity object
the gas couldn't escape
and we wouldn't see any of that.
If it were a massive object
it would really be screwing around
with the orbits of the planets
as it came through the inner solar system
but there's been no change in the orbit of Mars
no change in the orbit of the Earth,
no influence at all.
These are just manufactured fears.
Comet Elenin is just the most recent in this phenomenon
of peoples fear of the cosmos.
They're afraid of things that are happening.
Of course the big story is their afraid of
this fictional planet Nibiru, that doesn't exist.
That's supposed to do damage to us
in December of 2012.
There's a whole mythology here
and none of it is based on fact, it's all fantasy.
It's all wild speculation
and it's a shame that people are afraid of it.
Let me just conclude by mentioning
the issue of credibility.
Some websites say that you can't believe
the government or NASA,
that we are hiding objects like Nibiru,
or the brown dwarf with Elenin.
And this is just really crazy to a scientist
because we know that the science
comes from the academic community
there are very few scientists who work for the government.
Most of the telescopes are operated by universities.
Even NASA's Hubble telescope is operated by a university team.
It's the other way around,
the scientists provide the information to NASA,
not the reverse
and if you can imagine trying to
silence a hundred thousand astronomers,
who with their telescopes,
could be tracking Nibiru or Elenin
or any of these fictitious objects.
I can tell you, you couldn't keep six astronomers quiet
with an order from the government
let alone a hundred thousand.
There's no conspiracy here,
there's no danger from comet Elenin.
There's no danger in 2012.
I'm sorry that people get upset by it,
but believe me,
while there are plenty of real problems on the Earth
they don't come from the sky.
Thanks for listening.
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