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APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 4:05 am
by APOD Robot
All the Water on Europa
Explanation: How much of
Jupiter's moon Europa is made of water? A lot, actually. Based on the Galileo probe data acquired during its
exploration of the Jovian system from 1995 to 2003, Europa possesses a deep, global ocean of liquid water beneath a layer of surface ice.
The subsurface ocean plus ice layer could range from 80 to 170 kilometers in average depth. Adopting an estimate of 100 kilometers depth, if all the water on Europa were gathered into a ball it would have a radius of 877 kilometers. To scale, this intriguing illustration compares that hypothetical ball of all the water on Europa to the size
of Europa itself (left) - and similarly to
all the water on planet Earth. With a volume 2-3 times the volume of water in Earth's oceans, the global ocean on Europa holds out a
tantalizing destination in the search for extraterrestrial life in our solar system.
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Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 5:05 am
by ritwik
marvelous view of jupiter from europa
![Image](http://www.sciencephoto.com/image/410901/large/C0099538-Jupiter_from_Europa,_artwork-SPL.jpg)
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 5:23 am
by Ann
The fact that Europa holds more water than the Earth is not surprising at all. Europa obviously formed beyónd the "snow line", where the water of the primordial dust disk that formed our solar system was always frozen. The water out where Europa formed existed in its solid state, as snow and ice, and planetary bodies and moons like Europa could gather more and more of these ice particles and "snow balls" by reining them in through their own increasing gravity.
But the Earth almost certainly formed on the other side of the snow line, where the water of the primordial dust disk was gaseous. How easy was it for the Earth to rein in this water vapor and fill its oceans that way? Think of it like this. If you hold your hands above a pot full of boiling water, how easy is it to capture the water vapour that escapes from the boiling water? Can you gather it up? Can you created a solid ball of water vapor? Of course not.
Also consider this. Is the Earth a gas planet? No, the Earth holds very little gas. At least one reason for this is that the Earth was never massive enough to be good at capturing a lot of gas.
So as a matter of fact, Europa was born with a lot of water - make that ice - whereas the Earth was most likely born with extremely little water. In all probability, the Earth picked up its water when primordial comets, which had formed beyond the ice line and therefore contained a lot of ice, crashed onto the Earth during the era of heavy bombardment.
Ann
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 5:30 am
by TNT
At least we know now that if we ever run out of water on Earth we can look to Europa for help!
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 5:47 am
by Boomer12k
"Water, water everywhere...."
Getting it is hazardous to our health because of the Ionizing Radiation of Jupiter's Magnetoshere. Adequate protective measure have not been devised. So getting any water from there is problematical. Also, I wonder if it is contaminated with radiation....
:---[===] *
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 6:12 am
by stephinity
ALL THESE WORLDS ARE YOURS—EXCEPT EUROPA. ATTEMPT NO LANDINGS THERE.
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 6:28 am
by ritwik
stephinity wrote:ALL THESE WORLDS ARE YOURS—EXCEPT EUROPA. ATTEMPT NO LANDINGS THERE.
We are wanderers ..We come in peace
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 6:32 am
by ritwik
TNT wrote:At least we know now that if we ever run out of water on Earth we can look to Europa for help!
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
they don't seem too chummy with us
![Evil or Very Mad :evil:](./images/smilies/icon_evil.gif)
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 7:44 am
by Flase
It seems strange to me that people think water is running out. Where is it going? It's not disappearing into space.
Basically the poor countries can't look after their water supplies because the powerful use it as a bargaining chip.
Cochabamba Water Wars
Obviously we just need to be efficient about using the water we've got. If anything, the water levels are supposed to be rising and it's not hard to purify...
Water from Europa would cover the land and turn Earth into a water world. For what?
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 1:49 pm
by neufer
http://en.wikipedia.org/wiki/Europa_%28mythology%29 wrote:
<<In Greek mythology Europa (Greek Ευρώπη) was a Phoenician woman of high lineage, from whom the name of the continent Europe has ultimately been taken. The name Europa occurs in Hesiod's long list of daughters of primordial Oceanus and Tethys. The story of her abduction by Zeus in the form of a white bull was a Cretan story; as Kerényi points out "most of the love-stories concerning Zeus originated from more ancient tales describing his marriages with goddesses. This can especially be said of the story of Europa".
The etymology of her Greek name (ευρυ- "wide" or "broad" + οπ– "eye(s)" or "face") suggests that Europa as a goddess represented the lunar cow, at least on some symbolic level. Metaphorically, at a later date her name could be construed as the intelligent or open-minded, analogous to glaukopis (γλαυκώπις) attributed to Athena. However, Ernest Klein suggests a possible Semitic origin in Akkadian erebu "to go down, set" (in reference to the sun) which would parallel occident.
In the territory of Phoenician Sidon, Lucian of Samosata (2nd century AD) was informed that the temple of Astarte, whom Lucian equated with the moon goddess, was sacred to Europa: "
There is likewise in Phœnicia a temple of great size owned by the Sidonians. They call it the temple of Astarte. I hold this Astarte to be no other than the moon-goddess. But according to the story of one of the priests this temple is sacred to Europa, the sister of Cadmus. She was the daughter of Agenor, and on her disappearance from Earth the Phœnicians honoured her with a temple and told a sacred legend about her; how that Zeus was enamoured of her for her beauty, and changing his form into that of a bull carried her off into Crete. This legend I heard from other Phœnicians as well; and the coinage current among the Sidonians bears upon it the effigy of Europa sitting upon a bull, none other than Zeus. Thus they do not agree that the temple in question is sacred to Europa."
The paradox, as it seemed to Lucian, would be solved if Europa is Astarte in her guise as the full, "broad-faced" moon.>>
http://en.wikipedia.org/wiki/52_Europa wrote:
<<52 Europa is one of the larger asteroids in the asteroid belt, having a diameter of 300 km. It was discovered on February 4, 1858, by
Hermann Goldschmidt from his balcony in Paris. It is named after Europa, one of Zeus's conquests in Greek mythology, a name it shares with Jupiter's moon Europa.
Europa is approximately the seventh largest asteroid by volume. However, it has a low density (i.e. is highly porous), presumably through having suffered a particularly severe collision. In 2001, Michalak estimated Europa to have a mass of (5.2±1.8)×10
19 kg. In 2007, James Baer and Steven R. Chesley estimated Europa to have a mass of (1.9±0.4)×10
19 kg. A more recent estimate by Baer suggests it has a mass of 1.65×10
19 kg.
Europa is a very dark carbonaceous C-type, and is the fourth largest of this group. Spectroscopic studies have found evidence of olivines and pyroxenes on the surface,and there is some indication that there may be compositional differences between different regions. It orbits close to the Hygiea asteroid family, but is not a member. Lightcurve data for Europa has been particularly tricky to interpret, so much so that for a long time its period of rotation was in dispute (ranging from 5 and a half hours to 11 hours), despite numerous observations. It has now been determined that Europa is a prograde rotator, but the exact direction in which its pole points remains ambiguous. The most detailed analysis indicates that it points either towards about ecliptic coordinates (β, λ) = (70°, 55°) or (40°, 255°). This gives an axial tilt of about 14° or 54°, respectively.>>
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 6:26 pm
by ta152h0
"we come in peace to serve mankind "don't believe them europeans, they are tricking you.
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 7:29 pm
by BMAONE23
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 7:31 pm
by Beyond
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 7:54 pm
by saturno2
Jupiter¨s Moon Europa has more water that on the planet Earth.
It¨s amazing
With so much water, there will be some sort of life on the Moon Europa?
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Thu May 24, 2012 8:01 pm
by ta152h0
risking sounding like an UFO guy ( I am not ) some kind of primordial motion blobs are very possible. takes more that just water. Maybe lightning is also required.
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Sat May 26, 2012 11:30 am
by starchild24
I am wondering if i can share the Europa/earth water comparison to personal friends,in the interest of educating them? as is my quest, to share knowledge and increase the understanding of humanity, about the universe they are part of! I already embrace the wonderful cosmos that i am a child of..! I have always had an interest and indeed fascination for understanding, including being quite a long time amateur astronomer myself. (30 years +). And if permissible, how i would go about this??
Thank you!
![Idea :idea:](./images/smilies/icon_idea.gif)
Re: APOD: All the Water on Europa (2012 May 24)
Posted: Sat May 26, 2012 12:59 pm
by geckzilla
Print it out and hand it to them? Relay it to them through word of mouth? Share it to them on Facebook? Email the link? There's absolutely nothing wrong with any kind of sharing of APOD as long as you don't try to pass any of the work off as your own.