h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

You asked for a question on astronomy - here's mine. It's one of these questions that has had me thinking for a while and I can't get a satisfactory answer as yet.

Every November, the Earth enters this "fog" of meteors, commonly known as the Leonids - little particles of dust from some comet or other that passed through the vicinity some time ago.

Now, as far as I know, these meteors are caused by the solar wind blowing little bits of "cosmic dandruff" off the comets as they get close to the sun.

The solar wind blows stuff away from the sun at all points, so I would have assumed that if a comet swept majestically around the sun once upon a time, that any remnants it left around would be on its way out of the solar system at this time. Not so apparently, since we pass through the Leonids cloud (and the Geminids cloud etc) like clockwork once every year. The little bits of grit left behind from the comet do not appear to be moving. This doesn't make sense - the particles should have been either blown out by the solar wind, or if they have lost momentum they should have been sucked back into the sun. The idea of them staying in exactly the same place every year is a bit weird. What is happening here? Feel free to call me an idiot if there is something glaringly obvious that I have failed to consider!

CR

No you're not an idiot. That is a really well thought out question.

I don't know for sure, but until I find out here is what I think is happening. The solar wind is not all that powerful, so if the leonid particles are too big (and I think they are), they won't get blown away. Remember that "too big" is still freaking small. Now for the solar wind to cause a particle to spiral into the sun to things have to be considered, mass and cross section. But at any rate, it takes time to do so.

And that is what I think has happened. A comet passed by not to long ago, and the dust has not had very long to clear.

I will look it up though, and I will get back to you with the right answer

Good answer! That's esentially correct from what I know of comets.
The particles are dust-sized and bigger and take up residence in the comet's orbit much like the asteroid belt does between Mars and Jupiter (except those rocks are a lot bigger than dust).

If you've got a few moments sometime, why not check out my Observatory at http://www.h2g2.com/A222913

- Jimi X

BTW: Long-time no chat, eh? I haven't seen you around lately. The h2g2 community must be getting too big!

Me? No the community isn't too big. This semester has been horrible.

I have been far too busy to keep this site fresh. I hope to do more, but right now I'm working on a coupe of projects that might actually get me paid for my ramblings. Since I am a lowly college student, I need money like I need a hole in my head (my mouth).

Add in the fact I that I have enough extracurricular problems to choke a mule, and I have had no time to do anything that resembles fun.

I'm just happy that someone actually hangs around my site once in a while.

Well, there you are then!

I hope you didn't know anybody in that bus crash a few weeks back...

No, I didn't. Most of my friends are science/engineering majors, and they wouldn't have time for a shopping trip to New York.

It is too bad though, but what can you do?

Trust nobody and hope for the worst?

That might work, but isn't that exactly what "they" expect you to do?

Naw, 'they' expect you to trust everyone and hope for the best. Look at lines on the roadway, we 'trust' that the driver in the opposing lane will stay on their side and 'hope' that they aren't insane enough to ram us head-on.

- X