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Mars water surprise in Curiosity rover soil samples

bbc.co.uk

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Re: Mars water surprise in Curiosity rover soil samples

#41

Post by Coincoin »

tocomment wrote: post #38

I have questions about this. Can anyone help? How do they know the water is everywhere? How do they know it's not just in the one place they dug and nowhere else? Why hasn't the water evaporated? Isn't Mars almost a vacuum? Why didn't the water evaporate from the soil after being dug up but before being put in the oven? Could there be large underground frozen aquifers?

There is no water per say. It's just that the soil chemical composition is so that if you heat it a "few hundred degrees" a chemical reaction will produce water.

Re: Mars water surprise in Curiosity rover soil samples

#42

Post by tocomment »

Coincoin wrote: post #41
tocomment wrote: post #38

I have questions about this. Can anyone help? How do they know the water is everywhere? How do they know it's not just in the one place they dug and nowhere else? Why hasn't the water evaporated? Isn't Mars almost a vacuum? Why didn't the water evaporate from the soil after being dug up but before being put in the oven? Could there be large underground frozen aquifers?

There is no water per say. It's just that the soil chemical composition is so that if you heat it a "few hundred degrees" a chemical reaction will produce water.

Are you sure? If that's true I totally misread the article. I'll go back band check

Re: Mars water surprise in Curiosity rover soil samples

#43

Post by jccooper »

kposehn wrote: post #17
bfe wrote: post #15

Earlier quoted context omitted.

One of the central costs of a round trip to Mars is the fuel for the return flight. With enough water at Mars we can manufacture all the methane/oxygen rocket fuel we need on site. The Mars Direct mission architecture and the NASA Johnson Space Center's Design Reference Mission derived from Mars Direct both assume we send hydrogen from Earth to manufacture rocket fuel for the return trip at Mars, combining it with at…

Are there benefits to methane/oxygen outside what you referenced?

Methane, while less dense (thus requiring bigger tanks) has a higher specific energy than kerosene, and thus has a higher ISP (rocket efficiency). Methane is also less sooty and should have better cooling as its a "mild cryogenic" like liquid oxygen.

Basically, it's between LH2 (hydrogen: high ISP, very low density, very very cold) and RP-1 (kerosene: lower ISP, high density, room temp) and may be a good compromise.

And its derivable on Mars. Downside is there's very little flight heritage for a methane engine, so most of this is theoretical.

EDIT: Paper: http://thehuwaldtfamily.org/jtrl/research/Propulsion/Rocket%...

Re: Mars water surprise in Curiosity rover soil samples

#44

Post by jccooper »

tocomment wrote: post #38

I have questions about this. Can anyone help? How do they know the water is everywhere? How do they know it's not just in the one place they dug and nowhere else? Why hasn't the water evaporated? Isn't Mars almost a vacuum? Why didn't the water evaporate from the soil after being dug up but before being put in the oven? Could there be large underground frozen aquifers?

"How do they know the water is everywhere? How do they know it's not just in the one place they dug and nowhere else?"

Mars is believed to have a global soil layer, due to massive windblown dust storms. The area sampled is specifically chosen to be this dust and not local soil.

"Why hasn't the water evaporated? Isn't Mars almost a vacuum? Why didn't the water evaporate from the soil after being dug up but before being put in the oven?"

Air pressure is very low, though not close to vacuum. The water detected is probably bound in various chemical bonds, and is not ice, which indeed would sublimate quickly if exposed.

"Could there be large underground frozen aquifers?"

These are indeed conjectured. Large parts of Mars could be water glacier with a thin coating of dust.

Re: Mars water surprise in Curiosity rover soil samples

#45

Post by menubar »

sanxiyn wrote: post #40
gexla wrote: post #39

> . This striking block was dubbed Jake Matijevic, in honour of a recently deceased Nasa engineer. They are naming rocks. They haven't even stepped foot on Mars yet and they are already going space mad. And what's so special about getting a rock named after you? I'm sure there are enough rocks out there that everyone can have their own rock. Why not name a canyon or mountain after him?

There is a bureaucracy involved. To name a feature, you need approval from International Astronomical Union Working Gruop for Planetary System Nomenclature. No, I am not kidding. http://planetarynames.wr.usgs.gov/

Ah yes, the IAUWGFPSN. You don't mess with those guys. I think they have Gary Coleman on staff. He's a real hard case. Ironically, he killed a man for using the word "ironic" incorrectly.

Re: Mars water surprise in Curiosity rover soil samples

#46

Post by PeterisP »

gexla wrote: post #39

> . This striking block was dubbed Jake Matijevic, in honour of a recently deceased Nasa engineer. They are naming rocks. They haven't even stepped foot on Mars yet and they are already going space mad. And what's so special about getting a rock named after you? I'm sure there are enough rocks out there that everyone can have their own rock. Why not name a canyon or mountain after him?

If you are working for months with a bunch of rocks (as the NASA rover team is), then you need a way to distinguish rocks from each other, and to accurately reference which exact rock you mean in both documents and conversation.

Names are more memorable than numbers, and names with some meaning to you are more memorable than random words - that's it.

Re: Mars water surprise in Curiosity rover soil samples

#47

Post by ricardobeat »

abduhl wrote: post #18

For a comparison, typical values for water content on Earth are in the 15 to 50% range for the inhabited world. This is kind of an awkward way to present this data. They are talking about water content (which is by weight) and then translating to volumes which is not straight-forward in all cases. I don't know how revolutionary this is. A cubic foot of soil is, in my experience, quite a bit larger than most laymen th…

> A cubic foot of soil is, in my experience, quite a bit larger than most laymen think

Larger than a cubic foot?

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