Weekend Feature: Europa's Ocean --A NASA 2020 Mission in Search for Life

          


Researchers at NASA's Jet Propulsion Laboratory (JPL), are preparung a mission that could launch in 2020 and deliver the landers to Europa in 2026 to investigate whether life could ever have existed on the huge moon, which likely hosts an ocean of liquid water beneath its ice-shrouded shell.The proposed mission, much like NASA's recently launched Mars Science Laboratory Curiosity rover, it would assess the location's ability to support past and present life.

"Europa, I think, is the premier place to go for extant life," said JPL's Kevin Hand, who laid out the mission's basics in a talk here Thursday (Dec. 8) at the annual winter meeting of the American Geophysical Union. "Europa really does give us this opportunity to look for living life in the ocean that is there today, and has been there for much of the history of the solar system."

The researchers' concept calls for launching two identical landers (one a backup), each of which weighs 704 pounds (320 kilograms) and carries 79 pounds (36 kg) of scientific instruments. "That was sort of the overarching way to reduce some of the risk inherent in landing on the unknown surface of Europa," Hand said. He empasized that the lander mission is just a concept at the moment, and many details would have to be worked out before it could ever get off the ground.

Each robot would use a mass spectrometer, seismometers and several different cameras to study its landing site. The mass spectrometer would be able to detect various organic chemicals if they exist in Europa's ice, whereas the cameras and seismometers would gather data on the moon's geology..

NASA is also considering a different mission that would send a spacecraft to study Europa from orbit. The Jupiter Europa Orbiter mission would launch in 2020 and cost about $4.7 billion, officials said.

The deepest ocean on Earth is the Pacific Ocean's Marianas Trench, which reaches a depth of 6.8 miles awesomely trumped by the depth of the ocean on the Jupiter's moon, Europa, which some measurements put at 62 miles.

Although Europa is covered in a thick crust of scarred and cross-hatched ice, measurements made by NASA's Galileo spacecraft and other probes strongly suggest that a liquid ocean lies beneath that surface. The interior is warmed, researchers believe, by the tidal stresses exerted on Europa by Jupiter and several other large moons, as well as by radioactivity.

Most scientists believe that the subEuropan seas are locked under tens of kilometers of ice.  Heat is then conducted from the warm core by bulk convective motion of ice - huge chunks of frozen material literally carrying the heat away with them as they move up through the icy layer, shuffling and refreezing as they dump heat into space.

But Jupiter's Europa might not only sustain, but foster life, according to the research of  University of Arizona's Richard Greenberg, a professor of planetary sciences and member of the Imaging Team for NASA's Galileo Jupiter-orbiter spacecraft.

Europa, similar in size to Earth's moon, and has been imaged by the Galileo Jupiter-orbiter spacecraft. Its surface, a frozen crust of water, was previously thought to be tens of kilometers thick, denying the oceans below any exposure. The combination of tidal processes, warm waters and periodic surface exposure may be enough not only to warrant life, but also to encourage evolution.

With Jupiter being the largest planet in the solar system, its tidal stresses on Europa create enough heat to keep the water on Europa in a liquid state. More than just water is needed to support life. Tides also play a role in providing for life. Ocean tides on Europa are much greater in size than Earth's with heights reaching 500 meters (more than 1,600 feet). Even the shape of the moon is stretched along the equator due to Jupiter's pull on the waters below the icy surface.

The mixing of substances needed to support life is also driven by tides. Stable environments are also necessary for life to flourish. Europa, whose orbit around Jupiter is in-sync with its rotation, is able to keep the same face towards the gas giant for thousands of years. The ocean is interacting with the surface, according to Greenberg, and "there is a possible that extends from way below the surface to just above the crust."

"The real key to life on Europa," Greenburg adds, "is the permeability of the ice crust. There is strong evidence that the ocean below the ice is connected to the surface through cracks and melting, at various times and places. As a result, the , if there is one, includes not just the liquid water ocean, but it extends through the ice up to the surface where there is access to oxidants, organic compounds, and light for photosynthesis. The physical setting provides a variety of potentially habitable and evolving niches. If there is life there, it would not necessarily be restricted to microorganisms."

Tides have created the two types of surface features seen on Europa: cracks/ridges and chaotic areas, Greenberg said.The ridges are thought to be built over thousands of years by water seeping up the edges of cracks and refreezing to form higher and higher edges until the cracks close to form a new ridge.

The chaotic areas are thought to be evidence of the melt-through necessary for exposure to the oceans.

The tidal heat, created by internal friction, could be enough to melt the ice, along with undersea volcanoes - a combination of factors would give organisms a stable but changing environment -- exactly the type that would encourage evolution.

The Daily Galaxy via NASA JPL and space.com

Comments

[smartypants]

My bet is Anomalocaris live there at the top of the food chain. ;)

[Pradipta]

However our astronomical societies do not realize the theory of space mirror mystery, the progress of space study has no future. The theory of space mirror mystery is based on simple logical effects and has no complication. It clearly appears that from earth point we are able to see the real space objects in deep space within 150 million kilometers only; that means, nothing is real beyond 150 million kilometers and what is real beyond that does not appear to us but unlimited reflection in space mirrors we observing a boundless universe and using giant telescope like Hubble and others, our space organizations are giving us complicated theory step by step what have no base or reality except imaginary.

To the real and prosperous study of space science, there is no other alternative except the adoption of the theory of space mirror mystery. It leads the primary truth of deep space and positively it must lead the astronomers to disclose the subsequent truths/mysteries. Therefore we request to all to revise the astronomical study in true sense because the truth is always truth and we can never compromise with it. Http//www.spacemirrormystery.com

[smartypants]

WOW! I DEFINITELY need what ever you are smoking. I dont believe everything our scientist say but this is a little much. For this to be true 1000s of scientist would have to be complete idiots. To bounce between 2 mirrors, even curved mirrors, would be noticeable to any space telescope especially looking in the light not visible to the human eyes. You are saying that it took 2 satellites 10 years to get to the mirrors at the distance of the sun? Even if the planets were really closer and it was all bouncing signals, the distance x the speed is just a tiny bit farther. Maybe the signals they hit the edges of galactic space was really them bouncing off the actual mirrors?
If it was mirrors, wouldnt we see reflections of things lit up that the light passes through? Things like comet tails pops into mind first. Im sure there are more but this story has me going like 9999999999 mph brain wise. (hopefully in the right)
Have you ever sat between 2 mirrors? Its the eternal image going farther away. I see nothing like this in the sky.
Also if the rest of the solar system is the distance of the sun away (or closer) you are saying their heat absorption rate of sun light is actually lower since they are closer to the sun? That the satellites that went there and sent back pictures of their size and positions was wrong?
WOW! Reading the site has a lot of double talk to say the least. It gives opinions like they are facts. It uses phrases like our eyes merging with the Earth. Things like this impress simple people to say the least. MIRRORS?? I am sorry, I will consider it more IF mirror images of the planets start showing up. If the comets and asteroids suddenly seem to bounce in space like they hit something. Bro, I do believe in God and that he created all we see. I dont assume to understand how. I VERY SERIOUSLY doubt he uses MIRRORS!

[Larry]

Smartypants, you aren't fooling anyone. That website looks like a fifth grade science project, and about the same intellect has gone into it. What a joke.

[MarionScott]

Sounds like something out of the scientology bible...

[smartypants]

Hahahaha, I see now, its a sales pitch (you know, a SCAM). Related Items 1 - 4 are free but include # 5 and it cost $1001. The next part only says price reserved. Probably no matter what you order he will try to empty out your account.
Just for shits and giggles I tried to look at this like it might be true. Tried to think of an example that might make it right. Cant be done. Not 1 example came to mind. The anti proof is all I could come up with. For 1 thing the Earths shadow is 1,384,035 km long so where it says "The shadow of earth runs within the sun light. Since point of earth's shadow at the distance of 150 million Kilometers" is completely wrong. Also if the mirrors was true we would be able to see the sun reflecting back if the mirror was at 150 million km and the shadow ended at 1.3 mil km. It would look like a constant eclipse. Not to mention satellites would be able to see the whole reflection. Also for my last input on this, if you have a room thats all mirrors and put in a 40 watt bulb it light up the entire room brightly. Objects facing the light on only a little brighter on the bulb side. The mirrors reflect the light continuously in all directions. OK, I am done.

[smartypants]

I forgot to add though, feel free to input ANY proof you have (other than personal opinions). I mean you can add opinions too just dont call them proof. Change my mind if you can. Not a challenge, an invitation.

[anon]

The space mirror mystery that Pradipta and the site he/she links is probably a (rather badly) vulgarised interpretation of mirror symmetry, in topology. Put down that Michio Kaku DVD Pradipta!

[swarthy]

The space mirror mystery? Well, I guess it's about time the DG comments section recruited a couple of new crackpots. I look forward to the lively yet incomprehensible conversations between you and hologram universe guy.

[smartypants]

lol, ok, yes I went a little over board here. I keep thinking maybe I misunderstood the website and so I look at it again. Still it looks like he means real mirrors to me. I dont know. No other response from him/her so I am pretty sure it is a scam. It would probably be best to delete the entire comments section on this post but thats not up to me. At least then I wouldnt look as foolish as I read every thing I put in. Hahahahaha