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Comment by wkat4242 | Hacker News Reader

It's also awash with radiation from Jupiter. If there's life, it won't be as we know it :)

Europa is enticing because life would exist under a few km of ice, more than enough to prevent radiation from causing too much problems.

The hydrothermal vents, where the main sources of energy are hypothesized to be, would be deep enough.

Water is really good at radiation shielding.

I've heard that if you swim into a nuclear reactor spent fuel containment pool, you will actually measure the least radiation somewhere in the middle of the pool, thanks to shielding from the universe.

Spent Fuel Pool

https://what-if.xkcd.com/29/

The last lines are the best...

  But just to be sure, I got in touch with a friend of mine who works at a research reactor, and asked him what he thought would happen to you if you tried to swim in their radiation containment pool.

  “In our reactor?” He thought about it for a moment. “You’d die pretty quickly, before reaching the water, from gunshot wounds.”

I know someone who worked at a medical isotope reactor and there were no guns there, at least not in the reactor area. Security tends to be much much further outside ;)

After all, remember some things in a reactor don't react well to bulletsch.

Nice, thank you!

Does Jupiter emit any noticeable radiation?

Jupiter's radiation is so intense that Europa Clipper has a _super weird_ mission profile (a bunch of fly-bys instead of an orbit) so that the spacecraft doesn't spend too much time cooking in all that.

https://europa.nasa.gov/

The current Juno probe flies in 53 day orbits where only a few hours are in heavy radiation. It has made 48 orbits. The mission has been extended 7 years to 2025. If Juno runs low on fuel or the hardware breaks down, it will be crashed into Jupiter to avoid hitting and contaminating a moon.

Yes.

https://solarsystem.nasa.gov/planets/jupiter/in-depth/

> Near the planet, the magnetic field traps swarms of charged particles and accelerates them to very high energies, creating intense radiation that bombards the innermost moons and can damage spacecraft.

So basically like our van Allen belts but supercharged.

Technically, the answer to GP's question would be no, because Jupiter doesn't emit the radiation, it just traps and accelerates the particles (mostly coming from solar wind) in its magnetic field...

A lot of the radiation is produced by a ‘breeding’ process where volcanos on Io emit vapor that gets ionized and then accelerated to make more radiation that ionizes more vapor.

Katherine de Kleer said "It's like Io is the massive polluter of the Jupiter system" on the Lex Fridman podcast #184, the Io part starts ~14mins in for the curious

Thanks!

The quick answer: Yes and from a human visitor perspective, lethally high amounts. It's the single most intense emitter of radiation in the solar system except for the sun itself. If we wanted to colonize any planet with plentiful moons, Saturn would be a much better candidate at least in this regard.

Also, though another reply here mentioned Jupiter not emitting its own radiation, this isn't quite correct. It does, almost like a small pulsar.

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