Can anyone help me on this?

onceamarine · 7th October 2003, 08:49 AM

I'm trying to find out the exact orbital paths of all the planets...

More specifically I am trying to find out at which point, in it's orbit, each planets elipse is closest to the sun, and wether or not this happens on roughly the same side of the sun or not for all the planets.

Not sure if I have been able to state clearly what I am looking for or not, but any help would be greatly appreciated, I see a possible flaw in a widely recognized theory and I would like to investigate it further to test it out. I could be completely wrong, but you never know...

Thanks again,

Once A Marine

ceptimus · 7th October 2003, 08:56 AM

You want to know where the perihelions (closest approaches of the planets to the sun) are?

You realise they change over time? All the perihelions precess. Mercury's perihelion precession is the most famous, as it was used as a demonstration of the correctness of Einstein's theory, but all the planets do it, albeit more slowly.

See this site

and this one

onceamarine · 7th October 2003, 09:27 AM

Appreciate the help and links ceptimus, I did not realize that the planets perihelions precess...as a matter of fact, i did not realize that the word "Perihelion" existed.

With the exception of Mercury, which from what I gathered seems to precess quicker than the other planets, are all the perihelions roughly on the same side of the sun at the same time, or close to it?

wollery · 8th October 2003, 03:43 AM

I haven't checked, but I'm pretty certain that the fact that Mars and Earth had their closest approach in 60,000 years just last month means that Mars perihelion and the Earths perihelion are currently on opposite sides of the Sun from each other.

wollery · 8th October 2003, 12:49 PM

Okay I've now checked.
The perihelion points of the planets, measured in degrees anticlockwise from the vernal equinox point (when viewed from above the ecliptic), are;

Mercury 126
Venus 208
Earth 98
Mars 26
Jupiter 115
Saturn 207
Uranus 247
Neptune 180
Pluto 334

As you can see they're spread all over the place.
Also I was wrong about Mars and Earth having their perihelion points on opposite side of the Sun!

ps These values are accurate to about half a degree, as I used a fairly simple calculation from the basic orbital parameters - ignoring the orbital inclination which would have made the calculation a tad more complicated and taken a lot longer.

7th October 2003, 08:49 AM	#1
onceamarine Guest Join Date: Apr 2003 Posts: 8	Can anyone help me on this? I'm trying to find out the exact orbital paths of all the planets... More specifically I am trying to find out at which point, in it's orbit, each planets elipse is closest to the sun, and wether or not this happens on roughly the same side of the sun or not for all the planets. Not sure if I have been able to state clearly what I am looking for or not, but any help would be greatly appreciated, I see a possible flaw in a widely recognized theory and I would like to investigate it further to test it out. I could be completely wrong, but you never know... Thanks again, Once A Marine
onceamarine Guest Join Date: Apr 2003 Posts: 8

7th October 2003, 08:56 AM	#2
ceptimus puzzler Join Date: May 2003 Posts: 3,316	You want to know where the perihelions (closest approaches of the planets to the sun) are? You realise they change over time? All the perihelions precess. Mercury's perihelion precession is the most famous, as it was used as a demonstration of the correctness of Einstein's theory, but all the planets do it, albeit more slowly. See this site and this one
ceptimus puzzler Join Date: May 2003 Posts: 3,316	__________________

7th October 2003, 09:27 AM	#3
onceamarine Guest Join Date: Apr 2003 Posts: 8	Appreciate the help and links ceptimus, I did not realize that the planets perihelions precess...as a matter of fact, i did not realize that the word "Perihelion" existed. With the exception of Mercury, which from what I gathered seems to precess quicker than the other planets, are all the perihelions roughly on the same side of the sun at the same time, or close to it?
onceamarine Guest Join Date: Apr 2003 Posts: 8

8th October 2003, 03:43 AM	#4
wollery Protected by Samurai Hedgehogs! TLA Winner Join Date: Feb 2003 Location: Land of Eternal Hope Posts: 10,313	I haven't checked, but I'm pretty certain that the fact that Mars and Earth had their closest approach in 60,000 years just last month means that Mars perihelion and the Earths perihelion are currently on opposite sides of the Sun from each other.
	__________________ "You're a sick SOB. You know that, Wollery?" - Roadtoad "Just think how stupid the average person is, and then realize that half of them are even stupider!" --George Carlin

8th October 2003, 12:49 PM	#5
wollery Protected by Samurai Hedgehogs! TLA Winner Join Date: Feb 2003 Location: Land of Eternal Hope Posts: 10,313	Okay I've now checked. The perihelion points of the planets, measured in degrees anticlockwise from the vernal equinox point (when viewed from above the ecliptic), are; Mercury 126 Venus 208 Earth 98 Mars 26 Jupiter 115 Saturn 207 Uranus 247 Neptune 180 Pluto 334 As you can see they're spread all over the place. Also I was wrong about Mars and Earth having their perihelion points on opposite side of the Sun! ps These values are accurate to about half a degree, as I used a fairly simple calculation from the basic orbital parameters - ignoring the orbital inclination which would have made the calculation a tad more complicated and taken a lot longer.
	__________________ "You're a sick SOB. You know that, Wollery?" - Roadtoad "Just think how stupid the average person is, and then realize that half of them are even stupider!" --George Carlin