Planetary conundra...

Myrddin

Watching to the edge of the universe last night on Nat Geo. Couple of q's before they slip my mind...

1) Its was mentioned that Saturn is so light it would float on water. Does this mean Saturn is less dense than water? Amazing considering the size of its gravitational field...

2) IO, they were saying it has lakes/rivers of liquid natural gas. But the huiygens probe (typo) had picked up signs of organic material on the surface. Apparently its too cold there for it to form anything more complex, but that it could in the futre when our sun gets hotter. How could that happen, given the enourmous pressures required to form liquid from natural gas, and the large electromagnetic field generated by Saturn...

3) Mars, why do these shows continually go on about possible future terraforming projects here with super green house gases? Havnt we established that mars has no magnetic field due to the cooling of its core...and thus any atmosphere developed here would dissipate from solar winds...

Prob more q's to follow, thats all for now

Cheers

Kevster

EnterNow wrote: »

1) Its was mentioned that Saturn is so light it would float on water. Does this mean Saturn is less dense than water? Amazing considering the size of its gravitational field...

Yeh, it's true that it's less dense than water, but I don't know why you think the magnetic field has anything to do with this. Saturn is just a big ball of gas with a [probably] liquid metallic core. It's overall density means that it'd float in water.

EnterNow wrote: »

2) IO, they were saying it has lakes/rivers of liquid natural gas. But the huiygens probe (typo) had picked up signs of organic material on the surface. Apparently its too cold there for it to form anything more complex, but that it could in the futre when our sun gets hotter. How could that happen, given the enourmous pressures required to form liquid from natural gas, and the large electromagnetic field generated by Saturn...

Despite it's distance from the Sun, Io is relatively warm. The reason is that it is continually stretched/pulled as it orbits Jupiter. This frictrion then generates heat 'inside' the moon, which allows for the formation of such molecules.

EnterNow wrote: »

3) Mars, why do these shows continually go on about possible future terraforming projects here with super green house gases? Havnt we established that mars has no magnetic field due to the cooling of its core...and thus any atmosphere developed here would dissipate from solar winds...

I'm not sure about this one, but I think that some people now believe that Mars does in fact have a liquid core, and therefore a magnetic field.

Myrddin

Cheera Kev, I guess I just find it intteresting that something less dense than water, can form a gravitational field strong enough to support a system of moons.

With regards to Io, I understand its heated via tidal effects from Jupiter...but its always mentioned about the colossal radiation in the vicinity of Jupiter which would be fatal to any human life. I guess Io could support a much simpler form though?

Interesting about Mars, I always thought it was a dead planet. I guess it just proves fundamentally even our best guesses in astronomy are just that...guesses.

Kevster

EnterNow wrote: »

Cheera Kev, I guess I just find it intteresting that something less dense than water, can form a gravitational field strong enough to support a system of moons.

With regards to Io, I understand its heated via tidal effects from Jupiter...but its always mentioned about the colossal radiation in the vicinity of Jupiter which would be fatal to any human life. I guess Io could support a much simpler form though?

Interesting about Mars, I always thought it was a dead planet. I guess it just proves fundamentally even our best guesses in astronomy are just that...guesses.

Well, Saturn has a strong magnetic field because of it's metallic core, which is like a huge dynamo (same for Jupiter). The enormous amount of gas in its (Saturn's) atmosphere just means that it's overall density is less than water though.

Regarding Jupiter itself, I'm not sure that there's actually much radiation there... ...? i'm not the greatest physicist in the world though! While saying this, there are certain bacteria that can survive enormous levels of radiation - just look up Deinococcus radiodurans. It is nicknamed: 'Conan the Bacterium' (need I say more!)

Kevin

Biro

Kevster wrote: »

I'm not sure about this one, but I think that some people now believe that Mars does in fact have a liquid core, and therefore a magnetic field.

How easy or difficult is it to detect a magnetic field on a planet? Is the only way to confirm or deny to send a probe there?

Kevster

Yeh, I imagine so. I cannot think how else it could be measured, especially given how weak Mars' one is. With larger magnetic fields though (like around Saturn or Jupiter), I imagine you could measure them from a distance by how interstellar particles are 'deflected' off it. Anyway, the device used to measure them up close is a 'magnetometer'... ...and I've no idea at all how it works!

I imagine that there are bacteria here on Earth that could survive the Martian environment. They'd need to be anaerobic (or facultative anaerobes), of course, and be able to withstand radiation like Deinococcus radiodurans. People have talked about 'seeding' Mars with such bacteria which would then transform the atmosphere into something more 'human friendly'.

Like, on Earth, our atmosphere began with Methane. This was then gradually converted into a rich-in-Carbon Dioxde atmosphere by bacteria called the Methanogens. After that, plants grew and anaerobic bacteria proliferated, converting CO2 into Oxygen which allowed for the animal kingdom to become 'alive'.


Kevin