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General >> Discussion >> Acrobat in our solar system : comet 39P/Oterma
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Message started by frankuitaalst on 09/17/08 at 06:46:24

Title: Acrobat in our solar system : comet 39P/Oterma
Post by frankuitaalst on 09/17/08 at 06:46:24

The work of J Ross describes the Comet 39P/Oterma orbit as being a comet which changed its orbit quite dramatically after a close encounter with Jupiter .
This happened more than 40 years ago .
Ths comet was discovered in 1942.
Now the comet orbits in a 3:2 resonance outside Jupiters orbit , but some 45 years ago it was in a 2:3 resonace orbit in the inner solar system .
It must have passed through the L1 point of Jupiter towards the L2 point , ejecting him into the outer solar system in his present 3:2 resonance.  
The animation herunder shows 16 frames , each covering 10 years . Animation goes back in time .
(rotating frame to Jupiter )
The last picture is the total path of the comet over a period of 100 years from now in top view, sun centered .
As can be seen in the last pcture the comet must have changed its orbit even twice ( if the accurancy of the simulation allows this statement ) .

Title: Re: Acrobat in our solar system : comet 39P/Oterma
Post by frankuitaalst on 09/17/08 at 08:04:28

The next frames show the comets orbit , centered on Jupiter , at the time of closed approach.
Animation is this time forward in time .
The grey orbit depicts the orbit of Jupiters outerst biggest moon Callisto .
According to the timer on the screen the closest approach must have been january 1963.
L1 must be on the left , L2 on the right of Jupiter as the comet is heading towards the outer solar system.

Title: Re: Acrobat in our solar system : comet 39P/Oterma
Post by frankuitaalst on 09/17/08 at 08:31:20

For those interested in the possiblities of orbit transfers using the Lagrangian Points  the above author S.Ross made a powerpoint presentatation which can be found here :
www.esm.vt.edu/~sdross/talks/surrey-apr22.ppt

Title: Re: Acrobat in our solar system : comet 39P/Oterma
Post by frankuitaalst on 09/17/08 at 14:29:55

From the viewpoint of the Sun the 1963 manouever must have looked as following :
Oterma approaches from  under , gets close to the L1 point ( if it was right on the L1 point it had to be just in front of Jupiter ) , gets to the L2 point and leaves to the left , meaning it moves slower than Jupiter as it is ejected in the "outer" solar solar system .
The white orbit is Callisto's orbit .  

Title: Acrobat in our solar system : comet 39P/Oterma
Post by frankuitaalst on 09/18/08 at 01:38:20

As Oterma is a comet and is currently residing between Saturn and Jupiter , where does it come from and how did it come here ? Has it taken the "highway" jumping from Neptune to Uranus to Saturn to Jupiter ...?
To find out I ran the simulations backwards and found that for a long time ( several thousands of years ) Oterma can have been in an moderate elliptical orbit between Jupiter and Saturn , its orbit crossing Jupiters and Saturn twice !
Of course such an orbit is unstable .
Some 6000 years ago Oterma meets Saturn very closely  and is ejected in a highly eccentric orbit bringing it far beyond Pluto and inside Jupiters orbit with period of about 200 years .
Of course such a simulation has the disadvantage of accumulating errors over time  but it shows a possible scenario .
Here's the evolution of its period related to Jupiters .

Title: Re: Acrobat in our solar system : comet 39P/Oterma
Post by frankuitaalst on 09/19/08 at 01:04:26

The slingshot in post #3 in anaglyph looks as following .
The comet approaches from the left , makes a 180 turn and leaves Jupiter towards the outer solar system .
Picture was generated with a PBasic postgenerator .

Title: Re: Acrobat in our solar system : comet 39P/Oterma
Post by Nexus on 09/20/08 at 14:27:02

It might have once been a Centaur.

Title: Re: Acrobat in our solar system : comet 39P/Oterma
Post by frankuitaalst on 09/21/08 at 03:18:46


Nexus wrote:
It might have once been a Centaur.

I think your statement is true .
http://en.wikipedia.org/wiki/Centaur_(planetoid)
Some centaurs are believed to have characteristics of comets.

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