Questions about the solar system

"Jonathan Silverlight" wrote in message...
...
. . .
it gives me a chance to ask if anyone knows _why_ the planets aren't in
the plane of the Sun's equator. Most of them are closer to the ecliptic
than the equator.

'Lo Jonathan --

Here is a table that supports your last statement above...

ORBITAL
PLANET INCLINATIONS
ecliptic Sun's equator

Mercury 7.0 3.2
Venus 3.4 3.8
Earth 0 7.1
Mars 1.9 5.5
Jupiter 1.3 6.0
Saturn 2.5 5.5
Uranus 0.8 6.4
Neptune 1.8 6.4
Pluto 17.2 10.2

The figures for the angle off the Sun's equator were obtained
from a website on the study of sunspots. The only one that i
question is Mercury's... the figures for planets Venus through
Neptune all add up to around 7 or 8 (indicating that they are
all *between* the two planes). It would appear that either the
figure for Mercury is incorrect and should be more like "0.2,"
or that Mercury's orbit is a weird combination of maximum
7.0 degrees off the ecliptic and maximum 3.2 degrees off the
Sun's equator (each happening at different times in Mercury's
orbit.).

Also, the website did not give Pluto's figure for Sun-equator-
inclination, but this link...

http://www.fourmilab.ch/cgi-bin/uncgi/Solar

will show yet another site that equates heliocentric latitude
with the ecliptic and disregards the 7 degree difference
between the Sun's equator and the ecliptic. So i'm still not
certain if Pluto's actual figure is perhaps as high as 24-plus
degrees! (off the Sun's equator) My gut feeling is that the
ecliptic figure of 17.2 degrees minus the 7 degrees is
likely pretty close.

Note: You will want to set the "Heliocentric: lat." to zero
degrees to see all this more easily.

happy days and...
starry starry nights!

--
Tender is my love for thee
Oh star so close at hand,
Warming those so dear to me
As we lay on the sand...

It's so easy to believe
In all this beachin' fun,
That some day you and i will be--
Altogether one.

Paine Ellsworth

In message ,
Painius writes
"james" wrote in message
. com...

Hello everybody I have a few questions for a planetarium program that
i am writing. i hope some clever person can help me.

1 How many degrees is the earth kicked back off the ecliptic.

2 How far does the moon / mecury / venus vary off the ecliptic

3 How long exactly does the moon / mecury / venus take to do a full
rotaion of the sun / earth

'Lo James --

Some people mistake the Sun's equator as defining the
plane of the ecliptic. Since the ecliptic is actually defined
by the plane of Earth's orbit around the Sun, then the
answer to #1 above is zero degrees. And the plane of
Earth's orbit, also called the "ecliptic," is inclined about
seven degrees off the Sun's equator.

James could easily find these things for himself (homework, perhaps) but
it gives me a chance to ask if anyone knows _why_ the planets aren't in
the plane of the Sun's equator. Most of them are closer to the ecliptic
than the equator.
--
Rabbit arithmetic - 1 plus 1 equals 10
Remove spam and invalid from address to reply.

"james" wrote in message om...

Hello everybody I have a few questions for a planetarium program that
i am writing. i hope some clever person can help me.

1 How many degrees is the earth kicked back off the ecliptic.

2 How far does the moon / mecury / venus vary off the ecliptic

3 How long exactly does the moon / mecury / venus take to do a full
rotaion of the sun / earth

'Lo James --

Some people mistake the Sun's equator as defining the
plane of the ecliptic. Since the ecliptic is actually defined
by the plane of Earth's orbit around the Sun, then the
answer to #1 above is zero degrees. And the plane of
Earth's orbit, also called the "ecliptic," is inclined about
seven degrees off the Sun's equator.

The varying you ask about in #2 above is called the
"orbital inclination." The one's you ask for are...

Moon 5 degrees
Mercury 7 degrees
Venus 3.4 degrees

The Moon goes around the Sun just like a planet, always
falling toward the Sun. And it's period is the same as the
Earth's... 365.25 days. And it takes just about one month
to appear to go around the Earth (the Moon never really
goes fully around the Earth, instead making a slightly
scalloped orbital pattern around the Sun just like the Earth
does).

Mercury takes about 88 days to make one orbit around
the Sun, and Venus goes around our star in just about
225 days.

hth

happy days and...
starry starry nights!

--
A Universe of Beauty
Our Hubble often shows,
Let's not forget our duty
To pitch the way it Glows!

Paine Ellsworth