APOD: Galileo's Europa Remastered (2019 Nov 29)

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APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by APOD Robot » Fri Nov 29, 2019 5:05 am

Image Galileo's Europa Remastered

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, using improved new 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. What kind of life could thrive in a deep, dark, subsurface ocean? Consider planet Earth's own extreme shrimp.

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by Ann » Fri Nov 29, 2019 6:48 am

Infrared image of NGC 4038 (pink and shrimp-like)
and NGC 4039 (bluish and tail-like). Photo: Spitzer/NASA/JPL-Caltech - Dec 2003

I know I should comment on Europa (which is an interesting moon, I certainly agree), but the cosmic shrimp thing got me thinking about the Antennae galaxies NGC 4038 and 4039, which used to be called the "shrimp-tail galaxy" back when telescopes were not powerful enough to really see the shape of this colliding pair.


So I decided to google the shrimp-tail galaxy. My googling was an utter failure, since all I was shown was shrimps!

But when I searched for NGC 4038 Shrimp-tail galaxy, something wonderful turned up. A cosmic hummingbird! I have to show it to you!


And who knows, maybe shrimp swim in the dark deep oceans of Europa. But no hummingbirds fly there, I'll wager.


Cosmic hummingbird, galaxy ESO 593-IG 008.
Photo: ESO.








Terrestrial hummingbird. Image credit: Domenic Hoffmann/Pixabay


















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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by Boomer12k » Fri Nov 29, 2019 10:12 am

Do they have Thanksgiving on Europa???

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by Ann » Fri Nov 29, 2019 10:39 am

Boomer12k wrote:
Fri Nov 29, 2019 10:12 am
Do they have Thanksgiving on Europa???

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You mean the bird is a turkey? :wink:

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by orin stepanek » Fri Nov 29, 2019 11:56 am

[quote=Ann


And who knows, maybe shrimp swim in the dark deep oceans of Europa. But no hummingbirds fly there, I'll wager.


Cosmic hummingbird, galaxy ESO 593-IG 008.
Photo: ESO.








Terrestrial hummingbird. Image credit: Domenic Hoffmann/Pixabay
Ann
[/quote]

Maybe you could journey to the center of Europa and find this underground world where there would be hummingbirds! :mrgreen:
Orin

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by neufer » Fri Nov 29, 2019 1:27 pm

orin stepanek wrote:
Fri Nov 29, 2019 11:56 am

Maybe you could journey to the center of Europa and find this underground world where there would be hummingbirds! :mrgreen:
https://en.wikipedia.org/wiki/Google_Hummingbird wrote:

<<Hummingbird is the codename given to a significant algorithm change in Google Search in 2013. Its name was derived from the speed and accuracy of the hummingbird. "Hummingbird" places greater emphasis on natural language queries, considering context and meaning over individual keywords. It also looks deeper at content on individual pages of a website, with improved ability to lead users directly to the most appropriate page rather than just a website's homepage. The upgrade marked the most significant change to Google search in years, with more "human" search interactions and a much heavier focus on conversation and meaning. Thus, web developers and writers were encouraged to optimize their sites with natural writing rather than forced keywords, and make effective use of technical web development for on-site navigation.>>
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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by Roger » Fri Nov 29, 2019 1:49 pm

You have all been fooled. This is not actually Europa. My wife took this picture of the back of my balding head when I got out of the shower.

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by sillyworm 2 » Fri Nov 29, 2019 6:55 pm

I'm hoping,at 64, that someday I/we will find out some interesting information about this moon.Does anyone realistically believe we could send a probe that could explore/send back info..maybe even land on Europa within the next 20 years?

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by neufer » Fri Nov 29, 2019 7:05 pm

Click to play embedded YouTube video.
sillyworm 2 wrote:
Fri Nov 29, 2019 6:55 pm

I'm hoping,at 64, that someday I/we will find out some interesting information about this moon.Does anyone realistically believe we could send a probe that could explore/send back info..maybe even land on Europa within the next 20 years?
Sure.
Art Neuendorffer

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by Chris Peterson » Fri Nov 29, 2019 7:06 pm

sillyworm 2 wrote:
Fri Nov 29, 2019 6:55 pm
I'm hoping,at 64, that someday I/we will find out some interesting information about this moon.Does anyone realistically believe we could send a probe that could explore/send back info..maybe even land on Europa within the next 20 years?
We certainly have the technical ability to land a probe on Europa in the next decade or two. And there are mission proposals to do just that. It really comes down to balancing limited resources against a wide range of interesting projects.
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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by Ann » Fri Nov 29, 2019 7:07 pm

sillyworm 2 wrote:
Fri Nov 29, 2019 6:55 pm
I'm hoping,at 64, that someday I/we will find out some interesting information about this moon.Does anyone realistically believe we could send a probe that could explore/send back info..maybe even land on Europa within the next 20 years?
Surface features of Europa. Credit: NASA/JPL-Caltech
Helen Maynard-Casely of Phys.Org wrote:
Europa—attempt no landing here, but a fly-by is fine!
Actually though, Maynard-Casely is more optimistic about landing on Europa than the headline suggests. So maybe, in twenty years' time or so (or even less)...

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by Ann » Fri Nov 29, 2019 7:13 pm

neufer wrote:
Fri Nov 29, 2019 7:05 pm
Click to play embedded YouTube video.
sillyworm 2 wrote:
Fri Nov 29, 2019 6:55 pm

I'm hoping,at 64, that someday I/we will find out some interesting information about this moon.Does anyone realistically believe we could send a probe that could explore/send back info..maybe even land on Europa within the next 20 years?
Sure.

Looks like Norway to me. Although that two-legged horse-goat that Luke(?) is riding on is not indigenous to Scandinavia.

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by WWW » Fri Nov 29, 2019 7:17 pm

Does this Europa picture contain possible flakes, (geysers)?

Looking at the half dome of Europa (expanded+), to the far 10 o’clock position (not far from the rim, to the right of the white crack), there seems to be either a photo flake or possibly something erupting there. (Similar to Enceladus?). It would seem to be somewhat of a white plume.

Additionally there may be another white cloud near the 3:30 position (closer to center, near center of a light brown field). Then yet another at 6 o’clock center (not as bright). Not much of a shadow on any of these spots so less likely they would be a half sun lit hill or crater.

Just did a quick search on geysers on Enceladus and found an article in EarthSky not on Enceladus but on Europa, from just a few days back, claiming possible Europa geysers. https://earthsky.org/space/europa-water ... rs-goddard

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by BillBixby » Fri Nov 29, 2019 8:21 pm

Neufer has placed a comment on yesterday's APOD regarding shrimp which goes well with today's link to extreme shrimp.

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by dlw » Fri Nov 29, 2019 8:27 pm

I curious if there is speculation about what constitutes the rust colored material filling the cracks. I would presume it is from the interior ocean but perhaps its a reaction between the rising 'slush' and solar radiation.

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by neufer » Fri Nov 29, 2019 9:09 pm

dlw wrote:
Fri Nov 29, 2019 8:27 pm

I curious if there is speculation about what constitutes the rust colored material filling the cracks. I would presume it is from the interior ocean but perhaps its a reaction between the rising 'slush' and solar radiation.
https://en.wikipedia.org/wiki/Europa_(moon)#Composition wrote:
<<Since the Voyager spacecraft flew past Europa in 1979, scientists have worked to understand the composition of the reddish-brown material that coats fractures and other geologically youthful features on Europa's surface. Spectrographic evidence suggests that the dark, 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.

Another hypothesis for the colored regions is that they are composed of abiotic organic compounds collectively called tholins. The morphology of Europa's impact craters and ridges is suggestive of fluidized material welling up from the fractures where pyrolysis and radiolysis take place. In order to generate colored tholins on Europa there must be a source of materials (carbon, nitrogen, and water) and a source of energy to make the reactions occur. Impurities in the water ice crust of Europa are presumed both to emerge from the interior as cryovolcanic events that resurface the body, and to accumulate from space as interplanetary dust. Tholins bring important astrobiological implications, as they may play a role in prebiotic chemistry and abiogenesis.

The presence of sodium chloride in the internal ocean has been suggested by a 450 nm absorption feature, characteristic of irradiated NaCl crystals, that has been spotted in HST observations of the chaos regions, presumed to be areas of recent subsurface upwelling.>>
Art Neuendorffer

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Re: APOD: Galileo's Europa Remastered (2019 Nov 29)

Post by dlw » Fri Nov 29, 2019 10:02 pm

Thanks! My father's field was organic chemistry. He would have been fascinated by the wikipedia article.