APOD: Galileo's Europa (2024 Mar 29)

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APOD: Galileo's Europa (2024 Mar 29)

Post by APOD Robot » Fri Mar 29, 2024 4:06 am

Image Galileo's Europa

Explanation: Looping through the Jovian system in the late 1990s, the Galileo spacecraft recorded stunning views of Europa and uncovered evidence that the moon's icy surface likely hides a deep, global ocean. Galileo's Europa image data has been remastered here, with improved calibrations to produce a color image approximating what the human eye might see. Europa's long curving fractures hint at the subsurface liquid water. The tidal flexing the large moon experiences in its elliptical orbit around Jupiter supplies the energy to keep the ocean liquid. But more tantalizing is the possibility that even in the absence of sunlight that process could also supply the energy to support life, making Europa one of the best places to look for life beyond Earth. The Juno spacecraft currently in Jovian orbit has also made repeated flybys of the water world, returning images along with data exploring Europa's habitability. This October will see the launch of the NASA's Europa Clipper on a voyage of exploration. The spacecraft will make nearly 50 flybys, approaching to within 25 kilometers of Europa's icy surface.

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smitty
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Re: APOD: Galileo's Europa (2024 Mar 29)

Post by smitty » Fri Mar 29, 2024 12:51 pm

Any educated speculation about the cause of the rusty coloration of the long, curving fractures?

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Re: APOD: Galileo's Europa (2024 Mar 29)

Post by bystander » Fri Mar 29, 2024 2:23 pm

smitty wrote: Fri Mar 29, 2024 12:51 pm Any educated speculation about the cause of the rusty coloration of the long, curving fractures?
https://en.wikipedia.org/wiki/Europa_(moon)#Composition wrote:...
Spectrographic evidence suggests that the darker, reddish streaks and features on Europa's surface may be rich in salts such as magnesium sulfate, deposited by evaporating water that emerged from within. Sulfuric acid hydrate is another possible explanation for the contaminant observed spectroscopically. In either case, because these materials are colorless or white when pure, some other material must also be present to account for the reddish color, and sulfur compounds are suspected.
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Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
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Re: APOD: Galileo's Europa (2024 Mar 29)

Post by smitty » Fri Mar 29, 2024 2:42 pm

Thank you, bystander!

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Re: APOD: Galileo's Europa (2024 Mar 29)

Post by johnnydeep » Fri Mar 29, 2024 6:54 pm

bystander wrote: Fri Mar 29, 2024 2:23 pm
smitty wrote: Fri Mar 29, 2024 12:51 pm Any educated speculation about the cause of the rusty coloration of the long, curving fractures?
https://en.wikipedia.org/wiki/Europa_(moon)#Composition wrote:...
Spectrographic evidence suggests that the darker, reddish streaks and features on Europa's surface may be rich in salts such as magnesium sulfate, deposited by evaporating water that emerged from within. Sulfuric acid hydrate is another possible explanation for the contaminant observed spectroscopically. In either case, because these materials are colorless or white when pure, some other material must also be present to account for the reddish color, and sulfur compounds are suspected.
...
Alright, aren't "magnesium sulfate" and "sulfuric acid hydrate" themselves "sulfur compounds"? But that says both are colorless or white when pure, and then says that sulfur compounds" could explain the discoloration. So, what then - additional sulfur compounds?
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"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

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Re: APOD: Galileo's Europa (2024 Mar 29)

Post by johnnydeep » Fri Mar 29, 2024 6:55 pm

I can hardly wait the 6 more years for Europa Clipper to arrive at Jupiter! (Assuming it launches ok in October.)
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"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

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Re: APOD: Galileo's Europa (2024 Mar 29)

Post by bystander » Fri Mar 29, 2024 8:16 pm

johnnydeep wrote: Fri Mar 29, 2024 6:54 pm
https://en.wikipedia.org/wiki/Europa_(moon)#Composition wrote:...
Spectrographic evidence suggests that the darker, reddish streaks and features on Europa's surface may be rich in salts such as magnesium sulfate, deposited by evaporating water that emerged from within. Sulfuric acid hydrate is another possible explanation for the contaminant observed spectroscopically. In either case, because these materials are colorless or white when pure, some other material must also be present to account for the reddish color, and sulfur compounds are suspected.
...

Alright, aren't "magnesium sulfate" and "sulfuric acid hydrate" themselves "sulfur compounds"? But that says both are colorless or white when pure, and then says that sulfur compounds" could explain the discoloration. So, what then - additional sulfur compounds?

If some other material must also be present and sulfur is present, it seems reasonable to suspect sulfur compounds.
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

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johnnydeep
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Re: APOD: Galileo's Europa (2024 Mar 29)

Post by johnnydeep » Fri Mar 29, 2024 9:44 pm

bystander wrote: Fri Mar 29, 2024 8:16 pm
johnnydeep wrote: Fri Mar 29, 2024 6:54 pm
https://en.wikipedia.org/wiki/Europa_(moon)#Composition wrote:...
Spectrographic evidence suggests that the darker, reddish streaks and features on Europa's surface may be rich in salts such as magnesium sulfate, deposited by evaporating water that emerged from within. Sulfuric acid hydrate is another possible explanation for the contaminant observed spectroscopically. In either case, because these materials are colorless or white when pure, some other material must also be present to account for the reddish color, and sulfur compounds are suspected.
...

Alright, aren't "magnesium sulfate" and "sulfuric acid hydrate" themselves "sulfur compounds"? But that says both are colorless or white when pure, and then says that sulfur compounds" could explain the discoloration. So, what then - additional sulfur compounds?

If some other material must also be present and sulfur is present, it seems reasonable to suspect sulfur compounds.
My point was that they've already identified two sulfur compounds that are white/clear, but seem to be implying there must be some other sulfur compound to explain the color seen!
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"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

Roy

Re: APOD: Galileo's Europa (2024 Mar 29)

Post by Roy » Sat Mar 30, 2024 12:02 am

On the left side of the picture there is a white fissure that tails off into brown. A fact mentioned on Wikipedia is that there is massive ionizing radiation on Europa, 540 REM per day, (100 REM is sufficient to kill a person) which could alter whatever is upwelling in the fissures.