-RRH-

I read a speculation circulating by email, that we are somehow at risk from comet NEAT, discovered a few months ago. The author is concerned about electromagnetic interaction between the comet and the sun, and described the comet as "twice the size of jupiter".

Are there some astronomy buffs here who can give me solid info on said comet? Is it all that different from other comets?

Non-praying Mantis

Twice the size of Jupiter?!?

What that would mean is the solar system has another planet, or perhaps, if you prefer, another sun!

Certainly an object of that size would cause massive perturbations in the orbits of planets as it approached. It would actually have a gravitational effect on the sun!

Speculation by circulating email. Hmmm...you shouldn't put too much emphasis on rumors...

NPM

Friar Bellows

A comet is, for the most part, a highly diffuse, highly extended object, at least when it gets close to the Sun. If you include the dust and plasma tails, or the surrounding neutral hydrogen envelope, then it definitely can be larger than Jupiter. But if you're talking about the nucleus, no way dude! The nucleus is usually less than 10km.

I'm hankering for a really bright comet, like the great comets of 1843 and 1882.

avalanche:ix

i read the article too about it being twice the size of jupiter, which needlessly to say is absurd. i did some research but found no mention of it's actual size anywhere. the author does point at connections to the whole nibiru/planet-x conspiracy, which is funny.

Shadowy Man

As Friar said, being twice the size of Jupiter is not absurd. Being twice the mass would be!

The extended hydrogen corona around a comet can be huge. Also, the tail of a comet can be extremely long - read up on how the Ulysses probe flew through Hyakutake's tail millions of miles away from the nucleus.

I don't know what was in the message referred to by RRH, but i still doubt we are in danger from Comet NEAT.

-RRH-

Well, let's say that I already had a feeling this guy wasn't an authority on such matters. But neither am I.

So I haven't been able to find anything definite on the size of the comet, but it's pretty clear he was confusing the length of the tail with the size of comet itself.

And the electromagnetic interaction thing. Is there some genuine phenomenon that inspired him, and what did he not take into account?

Mageth

Not an anstronomer, but a quick web search reveals a ton of info about Comet NEAT (C/2002 V1).

Great images from at our about perihelion

Note the coronal mass ejection (obviously not caused by the comet, but interesting to study in how it might affect the comet).

Good technical info, with some more good images.

From the site, pertinent info:

"After more positions became available, the perihelion date was firmly established as February 18.30, the perihelion distance was given as 0.0993 AU, and the orbital period was about 37 thousand years. The orbit indicates the comet passed closest to Earth on December 24 (0.80 AU) and will be situated 5.7° from the sun around the time of perihelion."

"Using observations obtained by the German comet section up to December 26, Andreas Kammerer analyzed the brightness trend of this comet and has stated that the rapid increase in brightness "is typical of a small nucleus." "

I don't think we need be concerned about the EM interaction between the comet and the sun; perihelion was over a week ago. Further, while a nice, relatively bright, comet, it's not of spectacular size. I'm pretty sure we'd have all noticed something twice the size (mass) of Jupiter in the night sky. More than likely this was in reference to the length of the tail.