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Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds

theguardian.com

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Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds

#61

Post by RandyRanderson »

at_a_remove wrote: post #48
toshk wrote: post #16

Earlier quoted context omitted.

I always wondered why we are overly focused on the conditions that created life on earth. Arguably it makes sense to see similar conditions lead to life. But do we really know enough to assume that's only way?

Numerous other ideas exist for alien life, but most of them have their shortcomings. It all boils down to chemical reactions and physics. Imagine a universe of only helium. No valence electrons would be readily available, so chances are you are not going to see helium molecules. Lithium, sure, as a metal. Continue examining various smaller (and more plentiful elements). Fluorine? Well, only one slot available, so you…

Also water has one of the highest heat capacities [0] of elements that are common so this makes a great solvent that is more resistant to freezing and boiling. For this fact and the ones above, I see it as very unlikely that complex life exists outside any region that doesn't have liquid h20 almost all the time.

[0] https://en.wikipedia.org/wiki/Heat_capacity

Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds

#62

Post by qppo »

at_a_remove wrote: post #48
toshk wrote: post #16

Earlier quoted context omitted.

I always wondered why we are overly focused on the conditions that created life on earth. Arguably it makes sense to see similar conditions lead to life. But do we really know enough to assume that's only way?

Numerous other ideas exist for alien life, but most of them have their shortcomings. It all boils down to chemical reactions and physics. Imagine a universe of only helium. No valence electrons would be readily available, so chances are you are not going to see helium molecules. Lithium, sure, as a metal. Continue examining various smaller (and more plentiful elements). Fluorine? Well, only one slot available, so you…

Are there conditions in the universe where the chemistry required for life can occur with other compounds, that don't exist on earth? For example, extreme temperature, pressure, gravity, electro-magnetic field intensity, etc.

Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds

#64

Post by frogperson »

at_a_remove wrote: post #48
toshk wrote: post #16

Earlier quoted context omitted.

I always wondered why we are overly focused on the conditions that created life on earth. Arguably it makes sense to see similar conditions lead to life. But do we really know enough to assume that's only way?

Numerous other ideas exist for alien life, but most of them have their shortcomings. It all boils down to chemical reactions and physics. Imagine a universe of only helium. No valence electrons would be readily available, so chances are you are not going to see helium molecules. Lithium, sure, as a metal. Continue examining various smaller (and more plentiful elements). Fluorine? Well, only one slot available, so you…

This is an outstanding comment. You have made my day.

Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds

#65

Post by PaulHoule »

toshk wrote: post #16
gaukes wrote: post #2

Ceres is one of the more interesting candidates for life in our solar system. Ceres is in the habitable zone for our solar system (although just barely), it's surface temperature is -30 F (eq. to winter in Greenland), and it's detected that the water on the surface is 20% carbon by mass (though that can mean a lot of things).

I always wondered why we are overly focused on the conditions that created life on earth. Arguably it makes sense to see similar conditions lead to life. But do we really know enough to assume that's only way?

If your definition of habitable is "has liquid water" probably most of the habitable places in the universe are like Ceres, the moons of Saturn, even deep inside Pluto. Between the effects of pressure, geothermal energy, and gravitational tides you find liquid water in those places more than the inner solar system where water gets evaporated and blown away.

(The trouble is that those places don't have sunlight and probably fewer energy sources overall.)

It could be the answer to why we don't meet aliens: they couldn't care less about dry places like the Earth. You could travel the stars hopping comet to comet, but after spending 10,000 years like that you might be comfortable enough in your lifestyle that you wouldn't want to stop at a star. (All contingent on solving the energy problem, either you get lucky and find a lot of uranium or you invent D-D fusion.)

Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds

#67

Post by chc »

stx wrote: post #36

Is this actually H2O water? I read the article but I am still unclear. I am often excited to hear that water was discovered on some planet or moon but its always a disappointment to learn that its liquid methane or some other liquid that is not actually H2O water.

I think you must be thinking of some other word — maybe the fact that "ice" doesn't necessarily refer to water ice. If a science article says "water," they generally mean water unless the author's phrasing is extraordinarily sloppy.

Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds

#68

Post by ckuehl »

outworlder wrote: post #17

There goes the water rationing narrative in The Expanse...

The authors of The Expanse published an article last year acknowledging and paying tribute to the mission ("How a NASA robot messed up our science fiction"): https://www.nationalgeographic.com/science/2019/02/dear-dawn...

Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds

#70

Post by mturmon »

martinpw wrote: post #59
shkkmo wrote: post #38

Earlier quoted context omitted.

I suspect that isn't true, but it is an interesting question. There is a lot of water on the planet, some of it spends long periods locked up out of reach of drink ability. I would guess that at most water has been drunk multiple times, but that there is some miniscule a fraction that moved between icecap, permafrost and deep water table and has avoided being consumed by an animal since it arrived on earth. I would b…

There is a related interesting observation that every breath you take contains on average one molecule that was breathed out by Julius Caesar in his dying breath: https://www.sciencefocus.com/planet-earth/are-we-really-brea...

Avogadro’s number is very large.
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