If an ocean exists below the icy surface of Europa, then life might be living there.Submitted by Merlina at 2007-09-27 13:35:44 EDT
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Scientists have been looking at the other planets in our solar system for signs of biological evidence of life for many years, and found that in the giant plants, this was if not impossible, but pretty bloody unlikely.
Then they turned their attentions to the planets satellites, which they believed were worth considering, as some are as large or equal to the Earth’s moon. The most likely were Titan and Europa.
Europa is the sixth nearest and fourth largest natural satellite of Jupiter, which is in orbit 670,900 km from the large planet itself and is comprised mostly of silicate rock. This was studied by the Voyager 2 spacecraft in 1979 and was found to be 'as smooth as a babies bum' and its surface crust was a layer of water ice.
(It has been noted that the satellite cannot be made of compete water ice as the density of Europa, at 3040 kg m-3, is far greater than that if just ice).
The recent Galileo mission has provided us with information that we have so far on Europa, particularly that of the likelihood of liquid water being present in the satellites history!
Europa has strong albedo features as its icy surface reflects from the sun. It was also noted that there are fractures which criss-cross the satellite. These markings are believed to be caused by tidal forces under the ice, gravitational pull from Jupiter and signs of cryovolcanism – volcanoes erupting water, ammonia or methane. The conclusion was made that the ice crust is being continuously renewed from underneath its surface by warmer liquid water. Meaning that life could possibly exist as it did, and does, on Earth. I want to know if this is true!
Studies were carried out of the possibilities of there being a thin layer of ice but this was discounted as this would mean that the rocky surface would easily break this layer with minor impacts.
The possibility of there being a layer of liquid water under the ice is a study that has been going on for quite some time. Water, being one of the main constituents for life, would show a potential for terrestrial life being maintained underneath its icy exterior. Other constituents of course, being energy needed to build the molecules, the chemicals needed to assemble the living cells and light.
However, some organisms can live without light and can live on the ocean floor. Deep in the Earth’s oceans, there are organisms that can live without solar electromagnetic radiation. These thermophiles (heat-lovers) live on the ocean floor near the hydrothermal vents which produce sulfur and hydrogen compounds, under high water pressures, making it certainly possible that organisms could also live in the subsurface conditions of Europa...
The most successful way to actually find out the information needed to see if there actually is life under the subsurface of Europas’ icy crust would be for a probe to be sent there, and to have it penetrate the surface.
The probe would be deployed from an orbiting spacecraft with a timer set to start up the batteries just before its landing on Europa. Plutonium would be used to supply enough heat for the probe to survive the cold atmosphere. Once landed records & photos could be taken of the surface. Whether or not the probe will be able to penetrate or melt through the crust is sadly, as yet, unknown.
The likelihood of this being mission being carried out successfully will not be an easy one. Europas’ surface is believed to be approx 19 m thick which would make it incredibly difficult for the probe to penetrate or melt through the surface into the subsurface levels. Records would need to be taken of the chemical nature of the ice itself and of the liquid water below (if there is any).
Although Europa is of high scientific interest, it was state as recently as 2007 that no mission is currently being planned.
I want to go.
I want to be one of the first people to find out.
There MIGHT be life... Okay only organisms and all that but anyway... we were once just little bits of bacteria…….
Who’s coming with me?