Will Comet Elenin Destroy the World?

David Morrison

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On Internet conspiracy sites, this comet is being blamed for the March 10 Japan earthquake and tsunami, and it is supposed to either hit the Earth or knock us off our axis in September.

Remarkably, there
are many new websites suggesting just that. For the moment, the cosmic
conspiracy theorists are pushing aside the end of the world on 12/21/12
to make room for a more urgent threat from Comet Elenin, a faint long-period
comet discovered in December. On Internet
conspiracy sites, this comet is being blamed for the
March 10 Japan earthquake and tsunami, and it is supposed to either
hit the Earth or knock us off our axis in September. Many say it is
not a comet at all but a black hole or brown dwarf star, or that it
is a precursor of Nibiru, the 2012 death planet. Following are some
questions and answers about Comet Elenin from the NASA
“Ask an Astrobiologist” website.

Question: Please tell
me about Comet Elenin; there does not seem to be much credible information.
What is its size? I have heard it is twice
the diameter of Earth. Some websites say that Elenin is 80,000

km in diameter including coma. Can you put something out there about
what NASA knows about Comet Elenin, just to smooth things over before
people get crazy? Some are claiming that the comet has disappeared or
that there is a government plot to hide it.

Answer: I will be glad to tell you what
I know about Comet Elenin. Most of the information comes from amateur
astronomers, who have made hundreds of observations; see [http://www.aerith.net/comet/catalog/2010X1/2010X1.html].
Our knowledge of its orbit is constantly improving, with updates available
from the Minor Planet Center [http://ubasti.cfa.harvard.edu/~cgi/ReturnPrepEph?d=c&o=CK10X010].
Elenin is estimated to have an orbital period of about 10,000 years.

There are many photos posted on the web,
but be careful: the great majority of the images that come up in a Google
search are not of Comet Elenin but of other comets or artist impressions
(and some are fakes). For one good example see photos from Bernhard
Hausler taken in early March [http://thewatchers.adorraeli.com/2011/03/11/new-approach-of-a-comet-with-an-asteroid-elenin/].
The comet is too faint to be seen or photographed with a small telescope;
people who say the comet has disappeared or photos are being suppressed
are lying.

To understand questions about the size
of the comet, you must distinguish between the small solid nucleus of
rock and ice and the large atmosphere (coma) and tail that develop as
a comet approaches the Sun. The nucleus has not been measured but is
probably about 4 km across. The coma was reported to be about 80,000
km across in early April, with a tail estimated at ten times that length.
These are not unusual values for a comet, and both coma and tail are
expected to grow as the comet approaches the Sun (it is still beyond
the orbit of Mars at this writing on April 15). Some comets have developed
atmospheres that can be more than a million kilometers across. But please
remember that the atmosphere (coma and tail) is extremely tenuous—far
less dense than the best vacuum that can be produced in the lab. This
thin gas and dust can have no effect on the Earth or anything else.

Question:
The photo of Comet Elenin that is usually shown is a fake image and
it is actually comet 81P/Wild [
http://www.suite101.com/view_image_articles.cfm/2683306]. NASA supposedly has limited info and no
pictures. Oh, really? Not from the WISE satellite, designed specifically
to look at low light objects (like dwarf stars) with high
sensitivity
infrared? What about the South Pole telescope which has excellent IR
detection capabilities? How about Hubble? Nothing! Is this really the
dwarf star that would end all life on earth? Why doesn
t
NASA ever
say anything about it?

Answer: I am worried about the effects
of the fear campaign about Comet Elenin that is being waged on the Internet.
We all remember the Heaven's Gate cult that became so obsessed with
Comet Hale-Bopp in 1997 that the members committed mass suicide [http://en.wikipedia.org/wiki/Heaven's_Gate_(religious_group)].
I don't want anything like that to happen again, so I will answer this
and the following questions about Comet Elenin. Perhaps I can also promote
some critical thinking about these claims.

(1) Yes, I know that this photo (which
is not faked, just misidentified) is not of Comet Elenin. In fact, most
of the images that come up when you Google "Elenin images"
are not of Elenin. I don't know how this particular photo of Comet Wild
became associated with Elenin, except that Elenin is so faint that perhaps
some people wanted to substitute a picture of a brighter comet. (2)
The WISE (Wide-field Infrared Survey Explorer) telescope ceased operations
at about the time Elenin was discovered. This little comet, then in
the asteroid belt, was probably too faint to be picked up by WISE. (3)
I don't know much about the NSF telescopes at the South Pole, but in
the five months since the discovery of Elenin, the South Pole has mostly
been in continuous daylight. The South Pole would be one of the worst
places to go to study this comet. (4) The Hubble Space Telescope will
undoubtedly study Elenin when it is close to Earth, but I doubt that
anyone has used it yet. Most astronomers will wait to study the comet
when it is closer and brighter. (5) Do I need to remind my readers that
a brown dwarf is billions (with a B) of times more massive than a comet?
I suspect this brown dwarf rumor started when someone who is not familiar
with the sky turned a small telescope on Jupiter with its four moons.
(6) There is no reason that NASA (or the media) would be commenting
on this small faint comet. The only people observing it now are amateur
astronomers, who are tracking its orbit and its increasing brightness
as it approaches the inner solar system. There is a lot of craziness
circulating on the Internet, from people who either don't know much
about astronomy or are intentionally making up stories to frighten gullible
people. Shame on them!

Question: I read that a new calculation on Comet Elenin was posted
on the NASA Buzzroom stating
, "I've revised the 0.24
AUs down to 0.0004617 AUs on 16th Oct 2011" and that the Buzzroom
forum was taken down due to that comment. I also read that "an
inside source" from NASA is telling people that you guys are worried
about the comet knocking the ISS out of orbit, which is why the space
flights are being ended. I want to know if I am falling for the conspiracies
trap. Where are these people getting their "updated calculations,

and who is this "inside source"? I truly dislike when people
post these things in order to frighten

others.

Answer: Those are indeed weird statements
about Comet Elenin. Some of them come from an amateurish video that
was posted anonymously on the NASA Buzzroom website in late February
but is no longer available. There is no "inside source" from
NASA. That is a standard technique of conspiracy websites: make up some
story and then attribute it to a secret unnamed source so no one can
check up on the claim. I don’t know details, but you are partly correct
that the NASA Buzzroom website was taken down because of the video claiming
that the comet orbit had changed. Also, other people had posted several
offensive videos that had nothing to do with NASA or space. Because
of these inappropriate postings, the entire Buzzroom website was taken
down. I too get lots of offensive messages, but I don't post them. It
is important that you be able to trust what you read on a government
website.

NASA spaceflights are not ending, as
anyone can tell by reading newspapers or looking at NASA websites. I
am sure my readers realize that many people who are making comments
on websites don’t know what they are talking about. Some think that
the comet’s orbit will change suddenly and it may hit the Earth, whereas
in reality it cannot come much closer than 100 times the distance to
the Moon. Some question what mysterious force is pulling on it to bend
its path; they seem to forget that this comet is in orbit around the
Sun. Some think that we must know its mass to calculate its orbit; they
have apparently forgotten the simple experiment credited to Galileo,
who showed that objects of different mass behave the same way in response
to gravity (for example, cannon balls of different mass fall at the
same rate when dropped from a tower). One suggestion I saw was that
perhaps Elenin is not a comet; the individual speculated that it might
be a planet (perhaps Nibiru) or a brown dwarf or a massive black hole
masquerading as a comet. Please think about what a comet is. By definition,
a comet is a small object that sheds an extensive thin atmosphere of
gas as it approaches the Sun. If it were massive (such as a planet,
brown dwarf, or black hole), its gravity would hold on to the gas and
it could not develop a coma or tail. Finally, there are the astrologers
who seem to think that there are mysterious forces associated with alignments,
but I am confident that no readers of this article would make such foolish
errors.

David Morrison

David Morrison is a long-time NASA senior scientist and Committee for Skeptical Inquiry fellow. He now divides his time between the SETI Institute and the NASA Lunar Science Institute. He hosts the “Ask an Astrobiologist” column at NASA’s website.