Europa Ice

[voyagerwsh]

"Several impact craters on Jupiter's satellite Europa exhibit central peaks. On the terrestrial planets, central peaks consist of fractured but competent rock uplifted during cratering. Therefore, the observation of central peaks on Europa indicates that an ice layer must be sufficiently thick that the impact events did not completely penetrate it. We [have concluded] that the ice must be more than 3 to 4 kilometers thick."--Elizabeth P. Turtle and Elisabetta Pierazzo of the UA Lunar and Planetary Laboratory.

The thickness of Europan ice crust is a hot topic among many scientists. The range of estimates vary from 1-2 km to over 10 km thick. The UA report should shrink the variables to more than 3-4 km.

 http://pirlwww.lpl.arizona.edu/~turtle/craters_europa/

[voyagerwsh]

Although UA researcher report indicates at the impact crater the thickness of ice shall be more than 3-4 km, we do not know how thick it is at the crater. In addition, we are not sure how evenly the thickness of ice crust distributed around the surface. It may be some places are thinner and other places are thicker. Anyway, according to Galileo images there are tantalizing evidences of slush or water could have existed.  But at least, we understand it should be 3-4 km thick in many regions

[clifdweller]

Totally fascinating.I hope the ice layer is not thicker than 1km.I believe it was Yale who pointed out the fact that a signigficant ice layer may preclude the possibility of  evolution,due to it acting as a radiation sheild.

[voyagerwsh]

Yes, an icy crust would provide extra protection from radiation for life, if any, on Europa. But its not imperative, since we know microbes thrive on the cooling rods of nuclear reactor. Life can adjust itself accordingly to harsh environment over long period time of evolution.

[clifdweller]

Yea,but the counter intuative thing about the ice shielding rardiation,is that it may to too efficient. Radiation plays a huge role in evolution.There may not be enough to jump start cell structure.I don't think internal radiation would be sufficient.

[voyagerwsh]

Clif.. I figure out that we are on different aspects of radiation. You were referring to radiation on evolution, I was on the subject of impact of radiation to possible life on Europa. I suppose you are absolute correct that radiation plays important to the evolution of life on earth, sun light itself is one of radiation. What I like to stress out is microbes are very suitable to harsh radiation environment, as we understand the thriving microbes on the cooling rods of nuclear reactor. Maybe you were thinking of too low radiation provides inadequate energy to life? Try to look at deep Indian ocean chemosynthesis vents ecosystem.

BTW, good luck to your Titans vs Steelers this week.

[clifdweller]

The thing about the deep ocean vent life is that it is thought to have evolved elsewhere and adapted to it's environment on the ocean floor.

I really think Europa is perhaps the most important target for research in the solar system.We'll see what mars has to offer shortly.But my money is on the Jovian system for finding life.

BTW.I cried all afternoon. I guess our season is over........

Oh well.I hope the Steelers take the whole thing.

[voyagerwsh]

Lake Vostok, 4 km below the ice of Anartica, could have been home of unknown microbes to us for million of years. The lake has been isolated from the usual sources of atmospheric-derived energy, such as photosynthesis, a similarity of Europa? Possible. Primitive bacteria require only tiny amount of energy and nutrients at which cold icy enviroment would supply.

Steelers can be a 2002 vision of 2001 Ravens with stingy defense plus an improving QB can very well scramble under pressure. Steelers are legitimate AFC contender, Clifdweller.

[clifdweller]

What is the deal with Vostok? I heard the Russians were most of the way through the ice,then stopped and filled the hole with diesle fuel.That has been over a year ago now.I understand why they don't want to contaminate the lake,but why just abandon the operation?


Yea,I like the Steelers and I can't freaking stand the Ravens.We gave them a good game though.Put more yards and points up against their defense than any other team this year. Our defense stunk the place up though.We're to injury riddled to put together a decent stand like we have the last two years.We did manage to stop the bus though,just didn't have the secondary to deal with Cordell's air attack. The Steelers are a great team this year.

[voyagerwsh]

I believe that researchers has reached within 120 meters before stop drilling. A serious contamination consideration has been imposed to hall the exploration on the lake. They will take new process to examinate without any contamination.

Yep, altho' it's still too early to call, I like Steelers to win AFC central, Oakland Raiders to win AFC west, New York Jets to crown AFC east and match up in the AFC playoffs. Deeefense, it is said great defense to win championship games. Titans' D doesn't stand up this test this season as previously thought (due to some key injuries for some reasons.). Watch out the Rams, the best overall offense and defense team in the league.

[blacknebula101]

Will the thickness of the ice change the plans for the Europa probe that is to be dropped from the Europa orbiter?

[voyagerwsh]

I think it depends on what Europa Orbiter will find out, if it detects sea ocean beneath ice surface then a lander shall be possible. Keep in mind, there is no conclusive evidence that sub-ice water exists on Europa, but a strong suggestion.

[voyagerwsh]

I consider this topic is significant planetary science discovery, so repost here... Hope we can understand more from Europa. Thanks.  

Two discoveries by Alyssa R. Sarid, a undergraduate student at University of Arizona, has posted more evidences of liquid ocean on Europa.
1) "San Andreas-like faults in the crust of Jupiter's icy moon Europa provide evidence that the crust, floating on a liquid water ocean, has slipped over the globe, so that the poles recently have wandered hundreds of miles, a University of Arizona undergraduate student reported today."

2) By surveying images from Voyager and Galileo on the San Andrea-like faults on Europa, Ms. Sarid also discovered that zones in which surface ice plates have converged and disappeared completely.

A similar tidal ocean waves on earth is interestingly in resemblance on Europa. Yet, such sicentific discoveries enhance the hypothesis of ocean under the icy crust.  

www.spaceref.com/news/vie...l?pid=6753

 
 

[voyagerwsh]

I have found that it is interesting to notice that the pink brown color on the ridge of Europa is quiet similar to the pigment of microbes on earth. So, I repost the following thread from SDC.

------------------------------------------------------------
Shocking resemblance of infrared spectrum on Europa tinge and terrestrial extremophile bacteria presents very interesting aspects of pink colored ridge as hint of microbial presence on Europa. Extremophiles Deinococcus radiodurans and Sulfolobus shibatae are two of most probable species to survive at such frozen environment, according to astrogeophsysicist Brad Dalton. Additionally, they also have same pink brown pigment as the color on the ridge of Europa.

The probable cause of frozen "bacteria" on the surface could be transported from surging underneath salt water and frozen under extreme cold temperature. This is to present a very interesting case for the understanding of mysterious Europa infrared spetrum.

<img]"images.spaceref.com/news/...europa.jpg




What makes Europa pink?

[voyagerwsh]

Two main possible sources of heating energy on Europa are proposed. First, the tidal friction of Jovian and its closest moons, Io, Ganymede caused tug-war tidal flexing of heating to melt Europan icy crust in the Chaos region. Second, hydrothermal vent plume(s) on the ocean floor  melt through ice crust at 5 kilometers/1,000 years.

Model has been proposed by oceanographers John Delaney of the University of Washington and Richard Thomson of Fisheries and Oceans Canada, by using current knowledge of melting  in an ocean beneath the ice and it is consistent with the size of ice domes and movement of ice rafts on the surface of Europa.

www.spaceflightnow.com/ne.../19europa/