Hubble Images of Mars From 1990 to 2016, Photos at Opposition

This video shows images of Mars taken by the Hubble Telescope near the time of opposition of Mars. The photos start in 1990 and end at 2016. The meaning of the term opposition is explained. The reason the angular size of Mars changes from one opposition to the next is explained. The time period between successive oppositions is given. Astronomy Prof. Greg Clements