Yes, NASA, you absolutely need to go (back) to Triton

Space exploration is best interpreted, I think, as a specialised form of high-jumping. It is therefore sports, and that means we’re obligated to share our opinions about it with you, especially since 2020 is an Olympic year. I don’t make the rules here*, I just enforce them. Also, space exploration is interesting.

Anyway, NASA have just announced the finalists for the next wave of Discovery missions. Discovery is NASA’s small-scale exploration program, focusing on relatively minor missions to be launched alongside their flagship exploration projects. These four finalists will be given funding to further ‘mature’ their mission concepts, and in a year’s time as many as two could be selected for actual flight.

The four current Discovery concepts are:

  • DAVINCI+, a probe designed to analyse Venus’s atmosphere and perhaps send a lander down onto the planet’s surface.
  • VERITAS, a Venusian surface mapper.
  • IVO, an Io orbiter designed to explore the vulcanism of Jupiter’s innermost (significant) moon.
  • Trident, a flyby probe of Triton, Neptune’s largest moon.

NASA’s press release gives more details on each; rehashing them here would be silly. Instead, I’m going to do some Trident evangelism, because Trident would be some extremely cool shit and I need it to happen.

Triton is currently about 2,866,509,580 miles from Earth. It’s also the seventh largest moon in the solar system and, perhaps, the most interesting. Most major moons — ours excepted — formed from planetary accretion disks. The likes of Saturn’s Titan and the Galilaen moons of Jupiter have been planetary companions for their whole existence.

Triton definitely did not. How do we know this? For one, it orbits Neptune backwards. There’s no way for that to happen without having been captured at some point. This means that Triton began its life as an independent object minding its own business in the outer solar system before Neptune kidnapped it.

And Triton is big. Bigger than Pluto, in fact, by a hundred miles or so. Which means that Neptune has STOLEN A WHOLE-ASS DWARF PLANET. If not for it getting snatched up by a big old ice giant billions (?) of years ago, the science-fetish community probably be mourning Triton’s recent demotion from full-on planetary status.

There are other reasons to be interested in Triton beyond it being a kidnapped planet. It is somehow geologically active, appearing to respond to sunlight with nitrogen geysers and with significant cryovulcanism, as well. There’s even a thin atmosphere, probably generated by outgassing.

Triton’s unexplored, relative to the other Discovery targets: Neptune is a tricky target, and only Voyager 2 has ever visited. Our knowledge of one of the solar system’s most interesting moons largely stems from a few photographs taken in 1989. Only 40 percent of its surface was mapped during that flyby. Unsurprisingly, that has left many unanswered questions.

Venus and Io, both extremely interesting in their own right, are relatively easy targets. Admittedly, landing on Venus is somewhat less than easy, because Venus is a hell-world where it is so hot that it somehow snows metal. The Galileo and Juno probes (as well as the upcoming Jupiter Icy Moons Explorer, an SB Nation favourite), have demonstrated our ability to vex the Jovian system in something like our sleep. Trident’s task, as one of pure exploration, is vastly more ambitious and the window for arrival in 2038 is much narrower.

Obviously, I have no say in NASA’s decision making, and probably neither do you. But it’s still nice to have rooting interests, and I’m rooting hard for a Trip To The Stolen Planet. Even for a robot that would be one hell of a high jump.

*Wait, I do make the rules here.

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