Carl Sagan was a big promoter to have visual equipment mounted on space probe. He lost his argument with NASA to have camera mounted on the Venus probe, because others argued that camera increased weight with no value added. But since then, thanks to Carl Sagan, Viking, Voyager and Galileo missions all had camera's and produced astonishing pictures. It was also Carl Sagan who persuaded NASA engineer to turn Voyager II around on Valentine's Day in 1990, and Voyager II took a picture of the Earth while it flew away from the Solar system. It isn't so much for "scientific," but it is an effort to inspire people with the wonder of the universe.

Japan's lunar probe carries this legacy to have lunar HDTV transmission exactly just for that.