Friday, March 26, 2010

Pluto or Bust

Just a few days ago--almost exactly a week ago, actually--the New Horizons spacecraft crossed the orbit of Uranus on its voyage to the Pluto system.

For my money, this is about the most exciting thing NASA is doing these days. The spacecraft has been in flight since mid 2006, and won't reach Pluto until 2015. It's a really long trip. In the meantime, even the very best Hubble generated image we have of Pluto right now is a blobby, pixelated extremely low resolution mess. There's a lot to discover here. This is on par with the pioneering craft of the 50s, 60s and 70s that were really breaking entirely new frontiers in the solar system.

The Pluto system has been in the news a lot the last few years. Of course, most famously, the definition of a planet was finally established by the IAU, and that definition excluded Pluto. In less dramatic news (politically; from a scientific standpoint this was pretty exciting) Pluto was discovered to have two moons (apart from Charon, I mean. The Pluto/Charon relationship is more akin to a double planet pairing rather than Charon being a true moon of Pluto.) Nix and Hydra. The artwork provided here is a view from Nix (or Hydra) with the rest of the Pluto system in the sky.

Perhaps most importantly of all, and entire population of Pluto-like objects (called plutinos, unsurprisingly) has come to light in the last, oh, slightly less than twenty years, and an entire massive structure, the Kuiper Belt has gone from being an obscure hypothesis to being an accepted fact even more recently. The anti-Pluto was discovered (named Orcus which is appropriate... although I'd have loved to see it called Yuggoth. Oh, well. Missed opportunity for an esoteric in-joke.)

So anyway... there won't be a lot to report on about New Horizons for quite some time, obviously, but I've already eagerly been looking forward to the results of that mission for years, and I'll continue to work myself up with interest in the next few years as well until it finally starts to send in results.


Laurel Kornfeld said...

Pluto is still a planet, as are Ceres, Haumea, Makemake, and Eris. Please do not blindly accept the controversial demotion of Pluto, which was done by only four percent of the International Astronomical Union, most of whom are not planetary scientists. Their decision was immediately opposed in a formal petition by hundreds of professional astronomers led by Dr. Alan Stern, Principal Investigator of NASA’s New Horizons mission to Pluto. Stern and like-minded scientists favor a broader planet definition that includes any non-self-luminous spheroidal body in orbit around a star. The spherical part is important because objects become spherical when they attain a state known as hydrostatic equilibrium, meaning they are large enough for their own gravity to pull them into a round shape. This is a characteristic of planets and not of shapeless asteroids and Kuiper Belt Objects. Pluto meets this criterion and is therefore a planet. Using this broader definition gives our solar system 13 planets and counting: Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Haumea, Makemake, and Eris. At the very least, you should note that there is an ongoing debate rather than portraying one side as fact when it is only one interpretation of fact.

Joshua said...

Pluto is not a planet, according to the new definition. I know that the definition is controversial; please do not suppose that I am "blindly" commenting on anything. I don't need you to give me a historical or scientific recap; I know quite well what the definition is and how it was passed, thankyouverymuch.

Also, don't assume that just because it's a crusader issue for you that it's something that I, or any other blogger in the blogosphere, particularly cares about too much. None of Pluto's inate characteristics are changed by an arbitrary definition that the IAU decides to spring on it.