# Where can I find Helium 3 in our solar system?

What are the best locations within the solar system to find Helium 3 excluding the Sun? Where is Helium 3 most abundant after the Sun?

• Why do you want helium 3? Fusion with helium 3 is science fiction for now, and at least 30 years into the future before it might become science fact. According to many, it will always be 30 years into the future. – David Hammen Jan 8 '20 at 13:58

You wouldn't need to travel too far, the moon has been bombarded with large amounts of Helium3.

https://www.esa.int/Enabling_Support/Preparing_for_the_Future/Space_for_Earth/Energy/Helium-3_mining_on_the_lunar_surface

• Are there any additional locations outside of Jupiter as well? – Englishman Bob Jan 6 '20 at 23:07
• @EnglishmanBob you need something cold and relatively close to the Sun to both intercept a lot of 3He and to hang on to it for a zillion years so it can accumulate. See answers to How long does it take to refresh helium-3 on the moon? Mercury is closer but is probably so hot that the helium will not stay embedded in the regolith. Things near Jupiter will receive is $5.2^2 = 27$ times less 3He rate, but being colder and not impacted by meteors as frequently they might also be able to accumulate some. – uhoh Jan 7 '20 at 2:01
• @uhoh - You appear to be thinking the Sun creates helium-3. While it does do so, this happens in the Sun's core. For stars in the range of about one half to two solar masses, what happens in the core stays in the core while the star is on the main sequence. The helium-3 expelled by the Sun was not create by the Sun; it is (mostly) primordial. The giant planets have lots (lots and lots) of primordial gases, i.e., hydrogen and helium, and that includes helium-3. – David Hammen Jan 8 '20 at 13:23
• @DavidHammen I get all my information about 3He from Hollywood! Seriously though, I haven't discussed nor thought about how it is made. No matter how it happens, the Sun puts it a few microns down inside regolith particles of rocky bodies where, if cold enough, it can accumulate. I hadn't thought about going down into Jupiter's gravity well to get Helium, but if that's practical then whoever does it will become rich (in 3He at least, not sure about monetarily) – uhoh Jan 8 '20 at 14:12
• @EnglishmanBob Jupiter's not a great location to "mine" gases from. Its high gravity field isn't too much of an issue for an orbiting spacecraft, but its large powerful magnetic field gives it large intense Van Allen belts, which are thousands of times stronger than Earth's Van Allen belts. The radiation from these belts can damage electronics (and people), so a craft operating in the vicinity of Jupiter needs very good shielding. See en.wikipedia.org/wiki/Juno_Radiation_Vault – PM 2Ring Jan 8 '20 at 14:32

Where is Helium 3 most abundant after the Sun?

Jupiter, by mass, and Uranus and Neptune, by accessibility. This ignores that getting to and returning from Uranus and Neptune is extremely difficult.

Except for the Sun's core, the helium in the Sun is primordial in the sense that that helium was present when the Sun first formed, and mostly primordial in the sense that most of that helium was created during the Big Bang. The atmospheres of the giant planets are mostly hydrogen and helium -- i.e., mostly primordial.

Saturn's atmosphere is significantly depleted of helium compared to the Sun (and estimates of helium produced in the Big Band), and Jupiter's is slightly depleted in helium. This depletion is thought to be the result of helium somehow precipitating out of those gas giants' atmospheres. The atmospheres of Uranus and Neptune are much closer to primordial.