By the time this is published, New Horizons will be less than 5 days and 11 hours from its closest approach to Pluto. Last weekend, the probe stopped sending data for a while. This is now referred to as the July Fourth Anomaly. Apparently, the computer tried to do two computationally difficult tasks at once, and had a bit of a meltdown. But the autonomous autopilot noticed the problem, fixed it, and resumed communication after an hour and twenty minutes. Still, this put the unit off course, and wasted about a day because of the 9-hour communications delay between us and New Horizons.
The image there is the most recent that we’ve seen of the dwarf planet. The images from 3 July onward are the first in which we’ve been able to see some surface features. And we see in the southern hemisphere a lot of texture. What’s more, there is what looks like an enormous impact crater. Or maybe it’s a volcano. Who knows? The fact that the southern hemisphere looks more beaten than the northern hemisphere makes me think that there must be some kind of erosion process going on.
But the most obvious thing in the photo is that Pluto is kind of red. Meanwhile, it’s largest moon, Charon, is grey. So is the reddish color Pluto due to its atmosphere? It has a very small atmosphere. That could have something to do with it. Or it could be that Pluto and Charon are totally different. But they could still have once been part of the same object. This has got to be a particularly wonderful time for planetary scientists. I’m sure they are going crazy over all of the ideas that are being proposed.
Just in the last week, we’ve learned far more about Pluto than Clyde Tombaugh could ever have imagined. And the next week — not to mention over the next years as the data are analyzed — are going to be amazing. To me and probably most people, Pluto has always been just this fuzzy light in photographs. Just look at this image from Tombaugh’s original discovery:
Up to now, the dog Pluto has been more real than the planet. But now the planet is becoming real. It is coming into focus — literally. This is really going to be great.