Mercury Flyby 2 Options

[Holder of the Tw...]

It is time for this new topic.

Round Two

[Mariner9]

I was reading an article on Spacedaily, and ran across this real mathematical puzzler:

"Observations during this second Messenger flyby will almost complete the first high-resolution viewing of Mercury, adding another one-third of the planet surface to the 21% of territory not seen by Mariner 10 and first imaged by Messenger in January 2008," says Messenger Project Scientist Ralph McNutt.

I'm scratching my noggin over this one.
He appears to be saying: Mariner 10 + Messenger Flyby 1 = 21% unimaged, aka. 79% coverage.
But if you add another 33% coverage, you get 112% coverage, which can't be correct.

Or, perhaps: Mariner 10 + Messenger Flyby 1 = 79% Coverage. Of the 21% left unimaged, Flyby 2 will get 1/3 of that missing coverage, aka 7%, so the total coverage will go up to 86%.

Anyone want to chime in?