Little Pluto is a little bigger than anyone imagined.
On the eve of NASA's historic flyby, scientists have announced that the New Horizons spacecraft has nailed the size of the icy world.
Measurements by the spacecraft set to sweep past Pluto today indicate the diameter of the dwarf planet is 2,370km, plus or minus 19km. That's about 80km bigger than previous estimates.
Managers said there's only one chance in 10,000 that something could go wrong, like a debilitating debris strike, this late in the game.