Hellscape

In the Star Trek episode "The Savage Curtain," the intrepid crew of the Enterprise visit the planet Excalbia.  I forget why, because the planet was completely covered by churning seas of lava, so it wasn't exactly a great site for an away mission.  But when they get there, they find that there's one spot that's hospitable, and in fact has Earth-like conditions, by which I mean the typical Star Trek landscape of sand, styrofoam rocks, and scraggly vegetation.  It turns out that the livable area was created by some superpowerful aliens to provide a spot where Captain Kirk could have a battle involving Abraham Lincoln, Genghis Khan, and various other historical and not-so-historical figures to find out whether good is actually stronger than evil.

Okay, put that way, I know the plot sounds pretty fucking ridiculous, but don't yell at me.  I didn't write the script.

In any case, I was reminded of Excalbia when I read about a new study out of Oxford University using data from the James Webb Space Telescope.  The team looked at a recently-discovered exoplanet, L 98-59 d, which orbits a red dwarf star only thirty-five light years away, and found that it's unlike any other exoplanet we've thus far studied.

It's about 1.6 times the mass of the Earth, but for a planet its size has a fairly low density, and spectroscopic data has shown an atmosphere rich in an element you usually don't find -- sulfur.  Venus's atmosphere has some sulfuric acid, but L 98-59 d had a great deal more, mostly in the form of the toxic and vile-smelling hydrogen sulfide.  This is over a surface that appears, like Excalbia, to be largely molten.

Being chemically reactive, you wouldn't expect hydrogen sulfide to be long-lived in a planet's atmosphere, and it's sufficiently lightweight that stellar activity should readily blow it out into space.  Some process, therefore, must be generating it as fast as it's consumed either by being blasted out of the atmosphere or chemically reacted and then drawn down by convection of the liquid rock surface.  Apparently, something about the mechanics of a deep, silicate-rich mantle is causing the entrapment and release of the huge amounts of sulfur we see in the atmosphere, but how that works is still a mystery.  And given how far outside the norm L 98-59 d is -- or, what our models suggested was the norm -- it makes you wonder what else might be out there.

"This discovery suggests that the categories astronomers currently use to describe small planets may be too simple," said Harrison Nicholls, who was lead author on the paper.  "While this molten planet is unlikely to support life, it reflects the wide diversity of the worlds which exist beyond the Solar System.  We may then ask: what other types of planet are waiting to be uncovered?"

And that's considering the number of strange planetary types we already had in the exoplanet zoo, which include bizarre hycean planets, hydrogen-rich water worlds; chthonian planets, the cores of what used to be "hot Jupiters" that had their atmospheres stripped by stellar wind; and tidally-locked eyeball planets, with such extreme differences in temperature between their light and dark sides that they experience continuous blistering superhurricanes at the light/dark boundary.  That the sulfurous hellscape of L 98-59 d isn't something the astrophysicists had even thought up -- well, let's just say that what Carl Sagan called the "Encyclopedia Galactica" might be a lot longer, and weirder, than we'd ever dreamed.

So that's the cool news from the astronomers for the week.

Oh, and by the way, good turned out to be stronger than evil, although while finding that out Abraham Lincoln got assassinated again, which was kind of a shame.  On the positive side, Genghis Khan and Kahless the Unforgettable and various other execrable individuals went down to ignominious and well-deserved defeat.  Captain Kirk unsurprisingly got his shirt ripped open and gained valuable opportunities to show off his chest, but despite that the superpowerful aliens decided they'd gotten their answer and let the Enterprise and its crew go.  So in case you're wondering about philosophical questions like the relative power of good and evil, Star Trek solved it all in forty-five minutes, not counting commercial breaks.

Maybe we should turn Kirk et al. loose on whether intelligence always beats stupidity, because at the moment that one seems to be an open question.

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