And today is the anniversary of another planetary exploration first
I remember the "discovery" of the moon of Mercury as Mariner 10 approached the planet.
It made front page news in the newspapers. I did not recall about the ultraviolet detection,
just that they had seen a star that was mistaken for a moon for a while.
And as MESSENGER sweeps past that little world today, note that this is also the third
anniversary of the first landing on Saturn's moon Titan by the Huygens probe.
http://www.esa.int/SPECIALS/Cassini-Huygens/index.html