Once considered the furthest planet from the Sun, Pluto went from being the runt of the litter to being the first among the dwarf planets, the King of the Kuiper Belt. For some – particularly American nationalists who seem to take it personally that the only planet discovered by an American has since been demoted – this is seen as a horrible tragedy. However, going from being that weird little kid that no one really got along with to being the largest of many others weird little kids that everyone is fascinated with hardly seems like a demotion. Instead of trying to fit Pluto into a category that it really did not match well with, the International Astronomical Union created a new category for Pluto, Charon, newly-discovered dwarf planets in the Kuiper Belt, and vindicated little Ceres, who is the Princess of the Asteroid Belt between Mars and Jupiter. [Incidentally, if anyone should complain about a loss of status, it would be Ceres, who was considered a planet between 1801 and 1854. Demoted to “asteroid”, Ceres got to reclaim some dignity as a “dwarf planet”.]
On July 14, 2015, the New Horizons space probe conducted a flyby of Pluto, its companion moon Charon, and its four smaller moons. It sent back beautiful, detailed photographs of the dwarf planet – such that my first reaction was that God has an amazing marble collection.
What was once considered to be a dark, desolate ball of ice is now a vibrant, dynamic, colourful ice-world, with its own geological features and quirks. Instead of mere blobs in space, Pluto and Charon are distinct entities, just teeming with more secrets to explore.
Not long ago, Pluto was considered the back of beyond as far as the Solar System was concerned. Within only a couple of decades, we have discovered more smaller planetary bodies that orbit the Sun beyond Pluto, among them Eris, and an even stranger contender for dwarf planet status – Sedna, whose orbit is erratic and so distant from the Sun that it would hardly fit on a twentieth-century map. Plus, we have further observed the satellites of Jupiter and Saturn – moons that would be planets in their own right (or at least dwarf planets) if they orbited the Sun itself.
Nonetheless, we are discovering just how little we understand and know about even our own sun’s system, let alone the rest of the universe. We have barely explored our own planetary neighbours – the New Horizons mission is rather like climbing a mountain to visit those stranger neighbours that we often see but have never met, only to find that there are more people living further up the mountain.
There are many arguments for and against space exploration. Chief among the negative arguments is cost – equipment is expensive, fragile, non-reusable, and slow. Our own planet needs a lot of care and attention. Sending humans to colonize other planets, dwarf planets, or moons is a long way off. Even as we admire the beautiful photos of Pluto, we are nowhere closer to having a home anywhere other than Earth.
But that is not the only reason we explore space. We are slowly learning more about the universe that we inhabit. We are discovering exoplanets light-years away – what are they to us? Only windows into our own past and future. By studying how various planets orbit their stars (or orbited them at the time that the light reaching us left them, which in some cases was hundreds of years ago), we can make better educated guesses as to how our planet and solar system formed and what will happen to them as our sun continues its lifecycle. Learning about the planets in our own solar system is as much about ourselves and our own planet as it is about Pluto, Ceres, Titan, or Europa.
However, there is a hint of sadness in how we are taking more ownership in our solar system. For millions of years, Pluto was minding its own business, orbiting the Sun with Charon and their baby moons in a little family at the edge of the Kuiper Belt. Now, we have met them, and their isolation may be coming to an end as we send out more probes to the outer solar system. As for the inner solar system, we are looking to find resources on asteroids and satellites. We are looking to find life on Europa, Enceladus, Ganymede, and Titan, among others. We are looking to colonize Mars. Even if these are dreams still centuries out of reach, it is scary to think as to what could happen. Oceans may exist under the ice of Europa, but seeing as 95% of the North American people, fauna, and flora disappeared when a few explorers simply crossed an ocean on our own planet, what could happen to the Europan oceans without our even knowing?
And yet, the dark world of the Kuiper Belt has become a bit more inviting, a bit more familiar, because after decades of seeing our neighbours further up the mountain, we finally got to meet them.
And they were surprisingly friendly!