Yesterday would have been Clyde Tombaugh’s 109th birthday. He’s the astronomer who, patiently looking at plates of the approximate position of a predicted ninth planet, first spotted Pluto back in 1930. It didn’t turn out to be the massive ninth planet that people had been looking for (the calculations had included an observational error in the motion of Neptune, which suggested a phantom ninth planet that turned out not to exist at all), and in fact wasn’t even in a circular ecliptic orbit, but it was the most distant planet known when it was found.
Tombaugh died in 1997, before the IAU decided to define Pluto as a “dwarf planet” (along with Ceres, which had gone through a similar demotion long before, except that it was demoted all the way to “asteroid — the IAU promoted it into the new category of dwarf planet), but a piece of him is getting to participate in this mission — a portion of his ashes are on the New Horizons spacecraft. And yesterday, New Horizons returned two pictures to honor his birthday, showing the motion of Pluto’s large moon Charon, and finally resolving both bodies as more than just points of light:
In a few more months, New Horizons’s images of Pluto will exceed the quality of images from the Hubble Space Telescope, and in July it will get the best possible during a close flyby of the system. We’ll get to see the best of those photos within a day or so, but the bulk of the images will trickle down for a few months since New Horizons is so small and so far away that the bandwidth is very limited.
Pluto, here we come!