Distance between Earth and Mars by year

On Oct 28, 11:41*pm, "Greg D. Moore \(Strider\)"
wrote:
"Rand Simberg" wrote in message

...

On Tue, 28 Oct 2008 19:32:27 -0700 (PDT), in a place far, far away,
Skybearer made the phosphor on my monitor glow
in such a way as to indicate that:

Is there a table somewhere of the distance between Earth and Mars by
year? I'm looking for the distance in 2030.

When in 2030? *Don't you understand that planets are always on the
move?

Obviously he does, otherwise he wouldn't have bothered specifying a year.


Actually Rand has a point. I believe a better question is based upon
position of the planets. Something like when, near the epoch of 2030,
will Mars and Earth be at opposition, or superior conjunction, etc. By
asking for a distance from an entire year when the Earth/Mars synodic
period is 780 days this leaves a huge margin in the context of 365
days.

Anyway from Heavens Above website on the Solar System:

Mars distance from Earth on 1/1/2030 is 2.08AU
Mars distance from Earth on 4/1/2030 is 2.39AU
Mars distance from Earth on 7/1/2030 is 2.54AU
Mars distance from Earth on 10/1/2030 is 2.30AU
Mars distance from Earth on 12/31/2030 is 1.57AU

So there is no opposition between the planets in the calendar year of
2030 but there is a superior conjunction in the summer around 7/1 as
the 2.54AU indicates.