Oxygen estimate in Europa's subsurface Ocean, Spoiler alert: More than in ours Options

[john_s]

Are there ways to quantify oxygen in fresher ice from orbit?

We've detected oxygen on Europa's surface (probably trapped in the ice) with ground-based spectroscopy- see this Astronomical Journal article. It's hard to say just how much is there, because the strength of the absorption band depends on how close the molecules are to each other, but it's definitely present.

[nprev]

Aha! Thanks, John. Interesting. So high-res visible band spectroscopy from a Europa orbiter could presumably find small areas of high O2 concentration? You could probably use the same instrument for broadband terrain mapping & try to correlate oxygen enrichment with fresh-looking ice. Such sites would also be dandy places to look for geysers.

[MarsIsImportant]

There is no need to drill to get the submersible through the ice. Use a reactor core to create the heat necessary to melt through. This would make it dual purpose.

I'm also wondering whether the oxygen in the environment can be used somehow as a secondary power source (I don't know how to do that little trick). It could be done in combination with solar power, but that won't be an option under the ice. Tethering for power and communication would require too much mass for just the cord and would be impractical to unwind (high probability that something would get stuck). Maybe a lead-oxygen cell of some sort. Regardless, it would have to be fairly novel. A lot would depend upon how much is in the environment and could be captured.

The orbital missions have already been approved. That should give us a better feel for the oxygen answer before a more extensive dedicated mission below. Depending upon the results from that exploration, a narrow mission lander may or may not be necessary. Personally I think the combination of lander and submersible is a good idea and doesn't have to wait too long before becoming practical. The radiation would require shielding of some sort for any orbital or surface mission. A little extra weight for a self contained subsurface mission should be cost effective given the enormous dollar amount necessary to get the entire package to Jupiter.

My question is how much oxygen can really be expected in the ocean below. Although this paper suggests an extraordinary amount, is that real? What about potential ammonia in the water? How will that effect things?

[infocat13]

Does not ' LIFE" as we know it faver certain isotopes of oxygen or other ions? and what effect would cycling through the ice and radiation on the surface have on this? and could a orbiter tell us what was what?

[Juramike]

Hmmmm. Thinking this through from a purely physical standpoint:

Water ice on surface with isotopic ratio. Ionizing radiation hits. (Isotopic effect on ionization energy?? Would this matter to an appreciable extent??)
Oxygen reactive species created with (assumed) isotopic ratio as original ice.
Dioxygen (and ozone) forms in ice matrix.
Lighter forms have better chance of flying and escaping matrix and escaping off to space (but not much; difference for 18O=16O vs 16O=16O is m.w. 34 vs. m.w. 32)

Ice chunks with new ratio (favoring the heavier 18O=16O) go into the ocean which is a sealed environment.

So any oxidized compounds coming up should still have the oxygen isotope ratio that existed on the surface.
Not sure about sequestering into oxidized compounds. Theoretically at least, the 18O=O16 would be less reactive (stronger bond) and so O16 would be preferred to be oxidized into materials.

I don't think there will be an obvious isotope effect due to interaction with ocean materials. I think the isotope setting at the surface ice stage will be the defining moment.

[centsworth_II]

What about other gasses in the Europan ocean, perhaps released from the interior of the moon? There must be a buildup of such gasses beneath the surface of the ice. Perhaps huge pockets exist from which gasses can work their way up to the surface through cracks in the ice layer. Maybe some day events similar to the methane releases on Mars could be observed on Europa.

[Hungry4info]

Could that explain the "chaotic terrain" observed in Galileo images?

[Juramike]

Article on space.com describing an article soon to be in May issue of Astrobiology magazine (link to magazine website here).

Also released in http://www.astrobio.net/exclusive/3506/eur...-to-oxygen-burn

The new information released provides a better mechanism for crustal turnover, the tidal flexing due to Jupiter. And suggests that most of Europa's crust is less than 50 million years old. (Impact gardening, the synopsis states, would only distribute oxygen to about 10 m depth.). The tidal/tectonic cycling idea can thus distribute oxygen throughout the crust and the subsurface ocean.

There are some additional details in the news release regarding tectonic cycling and the formation of chaotic terrain of Europa. Especially interesting is how about 2 billion years would be required to saturate the crust in oxygen.

(Therefore the chemistry of the icy crust is oxidizing).

'"Spectroscopy done by telescopes on Earth or in orbit can tell what substances are mixed into the ice," Greenberg said.'

[MaDeR]

Astrobio is reported as having Trojan in Avast. I already sent email to them. I do not know if it is false positive, but I do not want go there again.

[Hungry4info]

I confirm. A javascript in there is picked up by Avast as a trojan. Dunno if it's a false-positive or not either.

[Greg Hullender]

Sophos reports it as well, but claims to deal with it.

--Greg