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Please forgive my ignorance. What makes Europa more likely to contain life than other moons thought to contain oceans like Callisto, Ganymede, Titan, Enceladus ... ? [1] [1] http://img.gawkerassets.com/img/18lqil4sqeremjpg/original.jp... [2] [2] http://io9.com/5827649/a-map-of-all-the-water-in-the-solar-s...
Please forgive my ignorance. What makes Europa more likely to contain life than other moons thought to contain oceans like Callisto, Ganymede, Titan, Enceladus ... ? [1] [1] http://img.gawkerassets.com/img/18lqil4sqeremjpg/original.jp... [2] [2] http://io9.com/5827649/a-map-of-all-the-water-in-the-solar-s...
Many planetary bodies are thought to have sub-surface water oceans of some variety, though Europa's is the most intriguing for several reasons. Given that Europa's surface is entirely water ice and geologically quite young that is a strong indication that Europa's sub-surface ocean is vast, warm, and consistently liquid over geological time periods. If, for example, Ganymede's ocean were as large and as warm then why has it not risen to the surface and formed an ice layer? This is backed up by the fact that Europa experiences an intense amount of tidal heating from it's galilean moon neighbors.
Because of this high amount of tidal heating, which on the neighboring moon Io is sufficient to cause widespread vulcanism, there is a reasonably good chance of significant hydrothermal vent systems within the Europan ocean. We've found on Earth that such vents can support chemotrophic life (through sulphides and serpentinization) which can support complex ecosystems which include animals such as shrimp and clams.
That isn't to say that other bodies may not harbor substantial sub-surface oceans or support extra-terrestrial life, but the case for Europa is that much stronger and so that much more a compelling target for investigation.
This is an awesome phenomenon. Yesterday we had a post re panspermia: https://news.ycombinator.com/item?id=6888412 Now think of an Europa with simple bacteria living in the water under the ice. These events are like cosmic sporulation: long strings of frozen droplets that could contain organisms, ejaculated into space like spores in the wind.
And promptly sterilized. Unfortunately most plausible life forms require meters of soil/rock surrounding them to survive the harsh space environment (probably more in the vicinity of Jupiter).
Earlier quoted context omitted.
And promptly sterilized. Unfortunately most plausible life forms require meters of soil/rock surrounding them to survive the harsh space environment (probably more in the vicinity of Jupiter).
You obviously didn't read anything about the research. The analysis was focused on the likelihood of large chunks of rock being ejected during an impact, large enough to provide sufficient protection from the interplanetary radiation environment for geologically significant periods of time.
Earlier quoted context omitted.
You obviously didn't read anything about the research. The analysis was focused on the likelihood of large chunks of rock being ejected during an impact, large enough to provide sufficient protection from the interplanetary radiation environment for geologically significant periods of time.
While I am not a biologist myself, I did work 2 years at the NASA Astrobiology Institute in a supporting role, where I learned all about the science surrounding this stuff. I don't know any astrobiologist who seriously believes that whatever microbes might exist in the comfort of Europa's inner ocean might survive free-floating in the harsh Jupiter radiation belts, where it takes hours or days (not millions of years)…
Found "Magnetosphere of Jupiter" on Wikipedia and it looks like the rest of my evening will be spent on this little tidbit. How could I never have heard about this.
As warm as the word vapor may sound it is actually really cold. Europa's oceans, if they exist, are -50°C and lower.
Hmm. I did not think that the temperature of Europa's oceans (below their probable icy crust) has been well-constrained. To the extent that it has, I think the subsurface temperature is expected to be much greater than -50C in many places (the mechanism is tidal heating). There is a general belief that Europa is likely to have significant liquid water below its icy surface. The phase diagram for water (first image at…
Earlier quoted context omitted.
You obviously didn't read anything about the research. The analysis was focused on the likelihood of large chunks of rock being ejected during an impact, large enough to provide sufficient protection from the interplanetary radiation environment for geologically significant periods of time.
While I am not a biologist myself, I did work 2 years at the NASA Astrobiology Institute in a supporting role, where I learned all about the science surrounding this stuff. I don't know any astrobiologist who seriously believes that whatever microbes might exist in the comfort of Europa's inner ocean might survive free-floating in the harsh Jupiter radiation belts, where it takes hours or days (not millions of years)…
Ultimately the possibility cannot be conclusively ruled out, and given the implications it's worth considering.
Earlier quoted context omitted.
While I am not a biologist myself, I did work 2 years at the NASA Astrobiology Institute in a supporting role, where I learned all about the science surrounding this stuff. I don't know any astrobiologist who seriously believes that whatever microbes might exist in the comfort of Europa's inner ocean might survive free-floating in the harsh Jupiter radiation belts, where it takes hours or days (not millions of years)…
Which is why it's far from a sure thing, only a possibility. However, if an object impacts Europa directly from a heliocentric orbit it won't spend much time in Jupiter's radiation belts. With enough luck maybe it would hit just the right patch of Europa to be captured in the ice and make its way down into the ocean without much exposure to radiation. Certainly that's a very unlikely event, as is simply getting a roc…
Earlier quoted context omitted.
Only at one atmoshpere of pressure.
The difference is negligible: http://i.stack.imgur.com/n6LXj.gif
[1]http://hubblesite.org/newscenter/archive/releases/1995/12/te...