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Old August 27th 03, 02:44 AM
Alan Moore
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Default Close encounters with Mars (Forwarded)

On Tue, 26 Aug 2003 17:08:55 -0400, John O'Brien
wrote:

I have a question about this. Opposition with Mars is on August 27. At
that point the earth is about 56 days past aphelion (July 2). Surely,
the conicidence of Mars beinng near perihelion and in inferior
conjunction with Earth which is in aphelion, has occurred with Earth
closer to earth's aphelion in less than 59619 years ?

Does anyone know ?


Almost certainly, but Mars' orbit is more eccentric than Earth's, so
the opposition being close to Mars' perihelion is more important than
Earth being close to aphelion. And since both orbits precess, finding
times when Mars is at perihelion, and that perihelion is close to
Earth's aphelion, and Earth is at aphelion, all together, are not very
frequent.

There's another occurence coming in about 275 years, however -- a
closer approach even than this one.

Al Moore