Let us say that at their closest approach, Mars is 55.7 million kilometers from the Earth and has an angular measurement of 25.1 arc seconds.
At their furthest distance, Mars is 401.3 million kilometers from the Earth, and has an angular measurement of 3.5 arcseconds.
If we use these two sets of values to solve for the angular diameter of Mars, and average the results together, what would we estimate the planet's diameter is?
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