Mars: from Conjunction to Opposition
The apparent diameter of Mars varies more than any other planet. This is because the distance between Earth and Mars changes dramatically between conjunction (on the far side of the Sun) and opposition (closest to Earth). Pressing the play button on the time control will increment time in steps of one day. The apparent diameter increases from 3.5" to 25" during a period of about a year in the animation.
I was going to say its size in the sky.
Quote "Mars increases from an angular size of 4.7 arcseconds in January to 25 arcseconds in August, as seen from Earth.
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