Cav's Place

As everyone should most definitely know, NASA‘s New Horizons spacecraft successfully flew by Pluto on July 14. As such, with Dawn also at Ceres since March, 2015 is the year when humanity first explored not only its first but its first two dwarf planets, or possibly the first three if you consider Charon‘s situation. This comes 26 years after Voyager 2‘s 1989 Neptune flyby, which completed the initial exploration of the major planets and sadly, along with the same spacecraft’s 1986 Uranus flyby, remains the only time humanity got anywhere near the ice giants. Also, bar absolutely shocking breakthroughs in propulsion and space travel, this will most likely remain the only time any man-made object will be in Pluto‘s vicinity for centuries to come.
This doesn’t, however, mean we’ve already received all the information we’re going to receive about Pluto; in fact far from it. The initial “browse set” may be winding down these days, but this is merely a very small and heavily compressed selection of what was gathered, meant to give the team and public something to look at quickly in case there will be problems later. The schedule then calls for the sending of a data set that doesn’t need to be analyzed right away and which should also be of little public interest, so the team will be able to take a well-deserved vacation before a heavily compressed version of the entire data set will start being sent, starting around the middle of September. Only after this will be safely on the ground, close to the end of the year, will the spacecraft even begin to send the complete, lossless data set, an operation scheduled to be completed no earlier than next October, and that’s assuming there will be no problems or delays.

And this brings me to probably the most frequently asked questions and the most common reasons why people who are too impatient and too used to instant gratification keep posting all sorts of angry messages. Of course, there are also the usual and expected conspiracy theories and those deeply bothered by the simple fact that any money are spent on space exploration, but a lot of the time people don’t seem to understand that the spacecraft truly does communicate at a painfully slow rate and downloading each file takes a long time. And that’s now, when New Horizons actually does seem to be sending data most of the time, because during the encounter phase it only communicated when it didn’t need to make observations, as it can’t do both at the same time.
What’s interesting is that New Horizons actually sends data faster than initially estimated, as the best speed I’ve seen reported is 2.11 kbps even though the mission plan assumed only 1 kbps at Pluto. And yes, that’s bits, so divide by eight for bytes. Admittedly, the fact that Voyager 2 managed 21600 bits per second, so a good ten times better, at Neptune may make those numbers appear particularly poor, considering the time that passed and the fact that most of the difference isn’t justified by the difference in distance, but New Horizons’ components were severely limited by size, weight, available power and, perhaps most of all, funding, so the team is doing the best they can with what they have. And, of course, there’s a lot more that needs to be sent than the eye candy people want so badly.

On top of that, since I’ve been trying to help in what little way I could by answering questions on the mission’s Facebook page and on the related posts on the NASA Solar System Exploration page, I can say there have been a few issues that were brought up infuriatingly often. Whether that was done via questions or statements, including harsh ones at times, all too many people proved not merely a lack of understanding, but also a lack of willingness to do as much as a simple search, both of which are disappointing but at the same time entirely unsurprising. As such, seeing as there are many excellent sources of answers and explanations available to anyone who actually is interested, I won’t even mention those other matters here.

What I do want to mention here, however, is the whole debate regarding Pluto’s planet status. Or, more specifically, I want to state very clearly that there should be no debate whatsoever on the matter and Pluto should have stopped being considered a major planet as soon as it was discovered that Charon doesn’t orbit it, but instead they both orbit a common center of mass placed between the two, outside Pluto. I couldn’t find exactly when that was determined, so do tell me if you know at least an exact year, but it was definitely known at least since some point during the ’90s and that’s when it should have been clearly stated that, as it doesn’t even dominate its own immediate vicinity, on its own Pluto has less of a claim to the status of major planet than even Ceres, which at the time was considered nothing more than an asteroid.
Speaking of Ceres, the very fact that it was considered a planet back when it was first discovered, in 1801, and then demoted to the status of asteroid as other bodies were discovered in the same general area of the solar system proves that dominating its orbit and clearing it of other bodies of roughly comparable size has been one of the criteria for determining what is and what isn’t a planet since at least the 19th century. It may not have been part of a formal definition, but it was there in practice, plus that we didn’t exactly have a formal definition before 2006. As such, the discovery of Eris and the realization that dozens or likely even hundreds of similar bodies were waiting to be discovered in that part of the solar system gave a second, very clear, reason to demote not only Pluto, but also a potential Pluto-Charon binary.
And that’s what should actually be discussed now, whether Pluto and Charon should in fact be considered a binary dwarf planet and therefore create this category, and my stance is that they definitely should be. After all, Charon doesn’t actually orbit Pluto, so it’s not a moon, and Pluto doesn’t only orbit the Sun, so it’s not a planet, dwarf or otherwise. Taken together, however, their barycenter does orbit the Sun and they dominate their immediate vicinity, as the other moons orbit both of them. Add the fact that they didn’t clear their orbit of other bodies of roughly comparable size and what we end up with is the very clear classification of Pluto and Charon as a binary dwarf planet. It’s the only classification that makes sense, rationally, unless of course someone prefers to ignore the fact that they’re massive enough to have reached hydrostatic equilibrium and wants to call them asteroids, as it happened to Ceres for about a century and a half.
To conclude, as long as you actually analyze the facts, which has actually been done since at least the late ’90s, Pluto’s obviously not a major, or classical, planet and I stand firm by the statement that all those who claim otherwise base their stance on nothing more than emotions and habit. At the same time, the IAU did approach the issue rather wrong when they made it obvious that their primary goal in creating a clear definition for planets was to prevent the list from growing too long with the addition of the new discoveries, and missed a huge opportunity when they chose to limit themselves to creating the dwarf planet category without also allowing for binary dwarf planets. But if they finally fixed some past mistakes, maybe they’ll fix this one as well in the not too distant future.

And now, before ending this post, please allow me to return to New Horizons and congratulate the team for this outstanding achievement. I also wish to deeply thank everyone involved, from janitors to team leaders and everyone in between, for their hard work and dedication. Thank you for reminding us, or at least those of us who may still care, to look up. Thank you for inspiring humanity, for offering hope, for proving what humans can truly achieve if even a small number of bright, talented, dedicated individuals set their minds to it and are granted even a tiny fraction of the resources the world wastes on pointless or downright harmful endeavors time and time again. This, and Dawn, and Rosetta and Philae, and also a few, all too few, other projects happening down here on Earth, these are the sort of things we should care for, support and focus on far more. And by “we” I mean humanity, all of us, wherever we are and however else we define ourselves, whichever boxes we choose to put ourselves and others into.
However, and I must apologize to the team for saying so, what I can hope for now is that this won’t remain such a notable achievement for too long, because far greater ones will follow it soon enough. Sadly, with the way things are going, that’s a terribly slim hope. But then again, when isn’t hope on a diet?