If you’ve been following New Horizons and its journey past Pluto, then you’ve already seen this image. On July 11th, New Horizons took a picture of Pluto’s “far side,” or the side that will be opposite New Horizons as it passes Pluto. It’s the side we won’t get clear images of. That side is always facing Charon. This is the best image we will ever get (until another probe is sent to Pluto) of Pluto’s Charon-facing side.
The dark spots at the lower part of Pluto are what’s puzzling scientists. We won’t get a clear picture of what they are, unfortunately. They’re evenly spaced, and much darker than the rest of the dwarf planet. The other side of Pluto, the side we’ll get to see clearly, also has a dark patch, called “the whale,” but it’s much larger. It’s quite likely it’s the same geological feature as these smaller spots. If they’re totally smooth, the angle at which they’re oriented toward the sun would explain why they’re so dark. However, it could also be a material that is dark or less reflective. We should be able to see with “the whale” in a couple days.
Other features we see are some impact craters, which was expected. The side we’ll see should have more impact craters, which is very useful in determining the composition of the interior of Pluto. Also, there are some features that look like channels. What could those be? Fractures on the surface? Linear geysers like on Enceladus? Could Pluto be geologically active? With its close relationship with Charon, there should be some tidal flexing, but not so much, because they always keep the same faces towards each other.
New Horizons is currently in the flyby phase of its mission, and will be closest to Pluto in about 36 hours. We should see some amazing pictures of Pluto, Charon, and one of its smaller moons, Nix, in the coming days. The other moons will be low resolution, because New Horizons doesn’t come near them.
Over the following weeks and months, high resolution images will slowly arrive back on Earth, as New Horizons doesn’t exactly have a broadband connection. We should see surprising new images often, which makes this short flyby very rewarding. It won’t be everything all at once, followed by a feeling of “is that it?” We’ll keep getting new images, so that’s great.
My biggest question is how similar will Pluto look to Neptune’s moon Triton? They’re both Kuiper Belt objects, and are similar in size. This should be interesting.
What do you think the features on Pluto are?