What is the angular diameter of Mars closest to Earth?
At the 2003 opposition Mars had an angular diameter of 25 arc seconds. In December last year it was about half that, as Mars was about twice as far away at that opposition. It changes each time due to the elliptic shape of both planets’ orbits, especially Mars’. Jupiter’s size at opposition varies between about 44 arc secs and just under 50 arc secs.
