# B Need confirmation of planetary distances

1. Oct 21, 2016

### Porsha

Hello.
I'm wondering if my numbers on my diagram are correct. I've drawn the sun to the left of a plain piece of blank printer paper. To the right I have calculated using millimeters mm representing a million miles. 1mm=1million miles. Mercury is two dots to the right that are 36mm-57.9mm to represent the orbital ring distance from the sun based on the orbit being an oval. Each of those numbers are the closest and farthest away from the sun. Venus is to the right of the sun represented as two dots 67.2mm-108.2mm showing the closest and farthest orbiting distance paths. Earth is to the right of the sun represented as two dots 93mm-149.6mm showing the closest and farthest orbiting distances. Are these numbers absolutely correct representations of the distances of the planets Mercury, Venus, and Earth? All of the distances calculated started at the edge of the sun and not the edge of the paper.

I would like an expert only on this subject to confirm these to be accurate.

2. Oct 21, 2016

### willem2

You really need not be an expert to look up the orbital radius and the eccentricity. For Venus and the Earth, the second number is the semi-major axis, but the first number doesn't make sense. The eccentricity of both planets is quite low.
you have $$\frac {S_maj^2} {S_min^2} = 1 - e^2$$

3. Oct 21, 2016

### willem2

For small values of e you get $$\frac {S_{maj}} {S_{min}} \approx 1+e$$[/QUOTE]
where smaj is the semi-major axis and smin the semi-minor axis, and e is the eccentricity.
e = 0.016 for earth and 0.0067 for Venus.

4. Oct 21, 2016

### Porsha

I have figured out where I have made errors in my figures. Thank you very much for your input.