At the Solar System’s Edge: Pluto

This is from Plait’s Under Alien Skies, of course. I’m not specifically interested in Pluto, but Plait caught my attention at once when I flipped to this chapter and read:

If you peruse the internet about Pluto, you may find articles asserting that from this distant world, the Sun would look like any other star in the sky. However, this is simply not true. The brightness of an object drops as the square of your distance from it. At its farthest, Pluto is about fifty times farther from the Sun than Earth is, meaning that the Sun will look 1/2500 as bright.

This may sound like the Sun would be seriously diminished, but in fact the Sun is about 400,000 times brighter than the full Moon in our sky. That means that even from Pluto, the Sun would still appear 160 times brighter than the Moon does from Earth. That would provide plenty of light to see by, like being outside at mid-twilight on Earth. It’s bright enough that looking directly at the Sun would still make you squint.

More profoundly, the Sun would be small. When Pluto is at its farthest, the Sun would be one-fiftieth as big as it appears from Earth. As it happens, that’s below the limit of the human eye’s ability to resolve an object, to see it as anything but a point. So in that sense, yes, the Sun would look like a star – a painfully bright one, but a dot in the sky. …

Faint as it would be, though, the Sun is still bright enough to create an amazing sight on the nearly airless Pluto: a blue sky.

The blue sky is because Pluto actually has an atmosphere, which I didn’t know. It’s an extremely thin nitrogen atmosphere, but at atmosphere that goes up about a thousand miles – and it’s enough of an atmosphere that it’s not only blue, but it separates into distinctly different layers of blueness because of the differentiation in particles suspended at different heights within the atmosphere.

Then this:

The ship touches down once more, and everyone shuffles off the ramp and down onto another platform. It’s local night here, but unlike before, where everything was pitch black, there’s a glow on the ground that allows you to see where you’re walking. There are shadows too, you notice, from the other people positioning themselves on the platform to get a good view of the sky. The shadows all point to your left, so the source of light must be on the right, and you turn and look.

There, hanging low in the sky, is Charon.

You flinch involuntarily; Charon is big. Much larger than the Moon as seen from the Earth. Just 750 miles wide, but only 12,000 miles away from Pluto’s surface, Pluto’s largest moon appears 3.5 degrees across, or seven times wider than the full Moon from Earth. It’s roughly the same size as a quarter held just 15 inches from your eye. Big. It feels like you could fall into it. And, surprisingly, even this far from the Sun, it’s still pretty bright. Despite the much fainter sunlight, Charon is closer to you, appears bigger, and is about twice as reflective as the Moon.

And so on, as Plait takes us for a tour.

This part about the brightness of the Sun reminds me of a great bit from XKCD, about the brightness of a supernova.

Also, Plait sidesteps everything about the argument having to do with Pluto being a planet. Personally, I’m fine with giving Pluto status as a planet regardless of other trans-Neptunian objects because it was discovered first and it’s big compared to most known trans-Neptunian objects AND because various people are continuing to call it a planet.

ALSO, I can’t help but think of the other Pluto. No, not the cartoon dog. I mean Hades, and my favorite filksong about Hades is “Persephone” by Vixy and Tony, which you can listen to here if you wish. I wish they would put out another CD or downloadable music, whichever.

Oddly, I don’t think I’ve read any Hades/Persephone retellings. If any of you have one to recommend, I’d be interested. I’m primarily interested if Hades is not a villain, though ambiguous is fine.

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7 thoughts on “At the Solar System’s Edge: Pluto”

  1. It’s not a novel, but there’s an ongoing Webtoon series where Hades and Persephone’s relationship is very different from the traditional myth. It’s a much more lighthearted romance.

  2. I am now keeping a list of the science books with engaging prose that you’ve recommended.

    Oh, I was thinking Lore Olympus, also on Webtoon, now with a graphic novel version. I haven’t read it. It looks pretty dramatic and angsty.

    The Hades story that does come to mind for me doesn’t have Persephone. It’s a manga called Collette Decides to Die. Slice-of-life about a doctor who falls into the underworld.

  3. Not a book, but Anais Mitchell’s Hadestown is a Broadway play featuring a retelling of the Orpheus story with Persephone and Hades as secondary leads, set in a Depression-era mining town. The music is pretty amazing, as is proper for a musical featuring Orpheus. Also check out Anais’s versions of (some of) the Child Ballads.
    I just know that there was a spate of teen books featuring the Hades/Persephone myth just as I was at the age of read them, but almost all of them were way too angsty for my taste.
    Come to think of it, Clare B. Dunkle’s Hollow Kingdom trilogy was loosely inspired by that myth, except it’s goblins, humans, and elves starting in a Victorian (?) setting. I believe one of Diana Wynne Jones’s books was also inspired by Persephone, but I remember not liking it as much as most of her others.
    @ Mona,
    I love Collette Decides to Die! It’s such a fun twist on the Olympic pantheon.

  4. There is a very well regarded computer game called Hades (with a sequel on the way) whose protagonist is Zagreus, one of Hades’ sons. There is a lot of family tension (it’s the Grecian pantheon) but basically everyone loves everyone else and is trying to work through their personal issues.

  5. It’s not a Hades-Persephone retelling, but Hades shows up as a non-villain secondary character in the Dresden Files book Skin Game. It’s been some time since I read it but I remember Hades as aloof but complex and interesting. Refreshing myself on a summary of the book, Hades says that Persephone came to him willingly, but Demeter wasn’t ready for an empty nest and caused trouble.

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