Best Meteor Shower This Year

LittleRedStar writes "This Wednesday night and Thursday morning is the peak of the Geminid meteor shower. This is the typically the best meteor show of the year with up to 100 meteors per hour. This year the moon is a nuisance, but with the peak predicted for early Thursday morning it is worth getting out and watching. Since the Perseid meteor shower was washed out from the moon and the Leonids were a bust, this should be the best for 2006."

Almost extinct comet?

[MichaelSmith]

If 3200 Phaethon is truly an asteroid, with no tail, how did it produce the Geminids? "Maybe it bumped up against another asteroid," offers Cooke. "A collision could have created a cloud of dust and rock that follows Phaethon around in its orbit."

OK but what if 3200 Phaethon occasionally has outbursts when it is closest to the sun. Doing that will blow a lot of rock off the surface and create meteor showers, it can also change the orbit.

Space probes try to perform trajectory changes when deep in a gravitational field because coupling with a large mass actually helps you get more velocity change from a given impulse.

Its not going to be fun for us of this object changes course one day and collides with the Earth.

Re:

[Bastard of Subhumani]

Space probes try to perform trajectory changes when deep in a gravitational field because coupling with a large mass actually helps you get more velocity change from a given impulse.

How do you work that out? Impulse = integral (F .dt) = change of momentum, momentum = mass * velocity. Seems the same impulse gives the same velocity change, if the mass remains constant.

Re:Almost extinct comet?

[MichaelSmith]

How do you work that out? Impulse = integral (F .dt) = change of momentum, momentum = mass * velocity. Seems the same impulse gives the same velocity change, if the mass remains constant.

Think about it this way: you are the Cassini probe transiting Jupiter on your way to Saturn. Approaching Jupiter its gravity sucks you in, increasing your speed. You do a burn at closest approach and increase your speed further. As a result you spend less time inside Jupiters gravitational field on your way out, so you lose less speed than you gained on your way in.

The effect works the other way as well. Your own gravitational field pulls Jupiter a bit towards you as you approach and the tug in the other direction is slightly smaller (because of your greater speed) after the flyby. The result is that Cassini and Jupiter exchange a small amount of momentum.

Re:Almost extinct comet?

[Nuffsaid]

Are they doing THAT? Are they CRAZY?!? Shifting Jupiter from its orbit? We are here busy worrying about asteroid impacts, and when you least expect it a gas giant hurls unstoppably toward our small planet, only because years before NASA was too cheap to buy enough fuel for its probes! They must be stopped NOW! To every celestial body its own momentum, I say.

Re:

[MichaelSmith]

Shifting Jupiter from its orbit?

I think the total velocity change from all our space probes was calculated to be about 1 foot per million years, or thereabouts.

Re:Almost extinct comet?

[jrockway]

I think the total velocity change from all our space probes was calculated to be about 1 foot per million years, or thereabouts.

Unacceptable! Won't someone please think of our children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children's children?

Re:

[Barryke]

appent "clone" But on a serious note: Amazing that this coincides with the sunflare. (is due to happen this evening about 6 hours from now in europe, i guess?)

Re:

[Rob T Firefly]

Is that all before or after the symbolic journey through my own death and subsequent rebirth as a star baby?

another answer attempt

[arete]

I have the general feeling that your answer is correct but nonetheless confusing. I would explain it this way:

If you pass near a large object, you accelerate towards it. If it's gravity doesn't cause you to crash into it, at your nearest point you'll be going much faster and then you'll slow down. This is generally akin to putting your car in neutral and going down into a ravine and up the other side.

Look at that analogy from the side, and you can see that the angle you had pointing "down" is much differ

Re:

[yo303]

coupling with a large mass actually helps you get more velocity change from a given impulse.

How do you work that out? Impulse = integral (F .dt) = change of momentum, momentum = mass * velocity. Seems the same impulse gives the same velocity change, if the mass remains constant.

Yes, for a given burn you always get the same velocity change, but you gain more kinetic energy if you are deep in a gravity well because of your higher speed (since KE is proportional to the square of your speed.)

If you burn

Re:

[MichaelSmith]

It's called a Gravitational Slingshot

There is a related effect most noticed when cycling in undulating terrain. You pick up speed going down hill then pour on the power going up the next hill. If you keep your speed up you get a higher average speed than you would on the flat.

Re:

[Bloke down the pub]

That's got more to do with respriation than gravitation. Or do you really belive you convert more gravitational potential energy to kinetic on the downhills than you lose on the uphill parts?

Re:

[MichaelSmith]

That's got more to do with respriation than gravitation

Imagine that I come to a complete stop on the climb and keep my feet on the pedals. I still need to do work to stay where I am but I don't gain any potential energy. The less time I spend climbing the less energy I lose while increasing my potential energy. So no, its not really the same as a gravitational slingshot. More of an analogy really.

Re:

[severoon]

Actaully...you're not doing any work if you're not moving. At least, no "work" as far as physics is concerned. Work = delta Energy = F*d*cos(theta)

We just don't know

[Silver Sloth]

The whole article reinforces just how little we know about what happens 'out there'. Most asronomy is extrapolating from very sketchy data to produce posibilities.

What I do know is that, here in the UK, there will be no point in going out to have a look unless you want to get cold and wet- all you'll see is rain and more rain.

To be honest...

[Bananatree3]

I'm not totally sure I would like a meteor shower. I mean, showers are supposed to cleanse, not kill.

Re:

[Bastard of Subhumani]

Golden showers don't cleanse.

Re:

[fatphil]

Urine is sterile though. Cut your hand on a rusty nail in a fence-post? You're better off washing the wound immediately with urine and then binding it than you are waiting 20 minutes before you get home and using some fancy schmancy medi-kit stuff.

However, I suspect the usage previously is intended to make one feel 'dirty'.

Re:

[Kazzahdrane]

+3 KazzPoints for making me chuckle before going to class. A terrible joke, but a joke nonetheless.

Re:

[Zadaz]

Meteor fire sounds very cleansing.

yay!

[oedneil]

We can all sit on blankets with our girlfriends and hold hands while we watch this.. oh wait..

Re:yay!

[RuBLed]

replace girlfrieds with Wii; replace hands with WiiMote..

there almost perfect...

Re:

[AdmiralWeirdbeard]

The funny/sad thing about this comment is that it made me realize that i have a bank of south facing windows and a wii, so i will probably end up doing jsut that....

Re:

[mano_k]

We can all sit on blankets with our girlfriends and hold hands while we watch this.. oh wait..

You saw the problem. It's much to cold this time of year! If it was summer ... oh wait...

Leonids may have been a bust

[ballpoint]

in terms of intensity; I saw only 4 common very faint streaks in 20 minutes.

However, I also was treated to a rare one that looked like a piece of shrapnel from fireworks coming down. That made it all worthwhile, certainly taking into account the unusually pleasant viewing conditions for a November night.

Finals

[aitikin]

Hmmmm. Middle of finals week. Is it really worth it? I'll do it, I might even stay up all night before that final anyway!

Re:

[denidoom]

I might be pulling an all nighter anyhow. that would be quite a treat to see a meteor shower when delirious from lack of sleep.

Re:

[Silver Sloth]

Did you know that NASA, in collusion with certain three-letter-acronym government organizations, has already developed a meteor shield?

Just keep taking the medication!

Another excellent prediction

[jfengel]

I knew that there was a meteor shower tonight as soon as I got up this morning, because it was cloudy and raining after several days of clear skies. Here in the DC area that's an infallible predictor of an astronomical event.

East Coast

[Joe U]

Remember:

If you live in the Northeast, just aim your telescope directly into the sun, the resulting blindness will be just as impressive as the shower thanks to the light polution on the eastern seaboard.

It's getting much worse too. I used to be able to see the Milky Way from about 15 miles out of NYC, now I have to drive at least 2 hours. (So, 30 miles at least, traffic sucks here too.)