In 1930, a young astronomer called Clyde Tombaugh noticed something moving across successive photographs of a starfield, and discovered Pluto.
In 2006, 30g of Tombaugh’s ashes were loaded aboard NASA’s New Horizons probe before it blasted off for Pluto.
Yesterday, New Horizons made its closest approach to Pluto. The photographs and data are still rolling in and it will take some time to analyse them, but NASA have published the images taken in the last week of its approach:
Back in April, I mentioned the mission as part of a discussion on Freeman Dyson’s speculation about life in the Kuiper Belt. The New Horizons photographs show no little green men striking a pose, but they lose none of their awe for being barren.
When New Horizons became the fastest probe to leave our planet in 2006, Pluto was considered to be the last planet to be discovered. As we’ve learned more about our solar system, Pluto has come to be recognised as the first Kuiper Belt object to have been discovered. The Kuiper Belt is a ring of rock, metal and icy planetesimals surrounding the solar system beyond the orbit of Neptune. Every planet in the solar system was formed by conglomerations of planetesimals that had ended up nearer the sun, so the Kuiper Belt could be seen as the hangout of the eternal wallflowers that missed the party.
For the science geeks among us, poor science reporting in the media is nothing new but it’s disappointing that so much coverage of the New Horizons mission has focused on Pluto having been downgraded to a dwarf planet, as though the mission is spending an undue amount of effort on someone who has been blackballed from an elusive club. What we’re seeing is not an anticlimactic look at an ex-planet but the beginning of the exploration of the Kuiper Belt, which is as close as we’re likely to get to a look at the solar system as it was before any of the planets formed.
New Horizons will continue its exploration with a close flyby of one or, fuel permitting, two Kuiper Belt objects over the next four years. It will then hurtle out of the solar system in the direction of the constellation Sagittarius.
Bon Voyage, Professor Tombaugh.