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Author Topic: How long does it take a comet to form?  (Read 777 times)

Offline thedoc

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How long does it take a comet to form?
« on: 23/02/2016 16:06:57 »
Jeffrey Cobb  asked the Naked Scientists:

    I'm just wondering how long it takes for a comet to form?


What do you think?
« Last Edit: 23/02/2016 16:06:57 by _system »


Offline Space Flow

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Re: How long does it take a comet to form?
« Reply #1 on: 19/01/2016 06:12:17 »
All compact material bodies form out of clouds of dust and gas. There is no set timeframe for a compact body to form. It depends on a lot of variables. The density and composition of the cloud. The amount of Spacetime turbulence plays a big role and can be boosted by a number of ways that will go into speeding the process up.
Generally a molecular cloud will be a turbulent environment to start with. If a violent event like a Supernova goes off in relatively close proximity, then a number of processes happen to the molecular cloud that inject energy in various forms.
First a huge rush of neutrinos blasts it's way through the cloud. Although weakly interacting, there will still be a large number of collisions. These can have effects like getting microscopic dust grains spinning at phenomenal speeds. These dust grains will set up through the agency of frame dragging, small vortexes throughout the cloud that will result in the accumulation of more gas and dust in the centre of each vortex.
Next will arrive ionising radiation from the SN injecting more energy and so amplifying the chaos conditions of the cloud.
This will be followed by the main player in all this.
A shockwave front emanating from the SN is spherically propagating through Spacetime. The physical mass of the star ejected spherically outwards at supersonic speeds into the Interstellar Medium.
I believe it is this fast ejector of material that slams into the Interstellar Medium setting up a Spherical Shock Wave. This freely-expanding ejector hits an inner termination shock, where its kinetic energy is thermalised, producing a very high temperature X-ray emitting plasma. Pressures inside the bubble build which helps balance the build up of interstellar gas and dust in front of the shock and maintain the expansion speed, while at the same time the high energy X-Rays ionise the gasses of the Interstellar medium ahead of the shock front.
This is a very violent event and to top it all off, the magnetic fields associated with the shockfront also act as particle accelerators giving the molecular cloud further high energy impacts.
All of this turns what was already described as a chaotic system into a maelstrom of spacetime vortices of all sizes. Some of those will blend with others, some will orbit others, all of them to different degrees will be focal points for the accumulation of higher concentrations of dust and gas spinning with the Spacetime vortex they find themselves in. The largest of these will turn into stars. Others will turn into planets. The majority will not get that big. They will just be accumulations of matter of various shapes and sizes.
The shockwave will move on triggering this process along the way as well as sending hi energy cosmic rays to travel throughout the Universe.
But now behind it, the spacetime vortexes will keep accumulating matter according to their size. The whole process comes to a stop when the largest vortex in any vicinity starts nuclear fusion. A star is born.
When that star fires up, it immediately ionises the remaining gas in it's neighbourhood and magnetically funnel's it to two opposing polar jets.
This achieves several things and it happens quickly.
By clearing all the unused gas and other ions out of the vicinity, it stops any further build up of massive bodies (planets, moons,asteroids, comets, etc).
Because it drives +ions to one polar jet and -ions to the other, it produces propulsion that drives it out of the original cloud and on it's journey around the Galaxy. Taking with it a large chunk of it's vicinity and everything it contained.
By getting rid of all that ionised gas it now leaves the remaining solid bodies in totally unbalanced orbits. The next period for this young solar system is to find balance. Most will crash into something bigger. Some will survive.

So back to the original question;

I'm just wondering how long it takes for a comet to form?
It can be a very short time as in hundreds of years, or it can take as long as it takes to build a star.

Welcome to the flowing Space Universe.
« Last Edit: 19/01/2016 06:23:33 by Space Flow »

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Re: How long does it take a comet to form?
« Reply #1 on: 19/01/2016 06:12:17 »


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