http://www.nasa.gov/home/hqnews/2005/jun/H...rontiers_2.html

Yeah, I know it ain't Saturn, but we don't seem to have any proper slot for Jovian news -- including yesterday's totally unexpected announcement that Amalthea's density is so low as to suggest that it's a highly porous ice object; maybe a captured Kuiper Belt Object reduced to rubble by infalling meteoroids. As Jason Perry says, this might explain those previously mysterious light-colored patches on Amalthea -- they may be its underlying ice, exposed by impacts that punched through the layer of sulfur spray-painted onto it by Io.

Scott Bolton has been pretty talkative to me already about the design of Juno. It certainly won't be as good in the PR department as Galileo or Cassini, but it DOES carry a camera -- as much for PR as for Jovian cloud science, according to Bolton. And since the latitude of periapsis of its highly elliptical orbit will change radically during the primary mission, I wonder if they might be able to set up at least one close photographic flyby of Io and/or Amalthea? (I believe, by the way, that this selection is a bit ahead of schedule -- and it certainly indicates that NASA's science program under Griffin won't be a complete slave to Bush's Moon-Mars initiative.)

Great to hear. With the whole lunar program being envisioned under the Moon/Mars program, it is good to hear this was selected. Also, it is nice to see another outer solar system mission entering planning...I mean, after New Horizons launches next year, we would have no outer solar system missions in development!

I take it this puts to bed the possibility of an NH2 ?

Does Juno have a website ?

I'll create a Jovian section for the forum in a bit

Doug

Any proposals on what kind of camera?

No website yet, and I have no details on what kind of a camera -- Bolton wasn't THAT talkative. I'll contact him again to see if a website is about to appear -- and, if not, I'll write my own article on the mission.

By the way, Doug, would it be possible for you to capitalize "Juno" in my original topic name? As usual, I screwed up on my capitalization.

Postscript: the mission selection actually was planned for last month. I'd lost track.

They can't return to Jupiter without taking a decent camera

Atmosphere sounding instruments can also return very interesting images, witness infrared imaging spectrometers on Cassini and Galileo.

Also, some non-imaging instruments return truely spectacular images. The MOLA laser altimeter on Mars Global Surveyor is a non-imaging instrument, and it's "primary" data pre-flight tended to be described as the surface profiles from single passes, but the dense coverage it returned of altimetry data, *WITHOUT* gross artifacts in the form of pass-to-pass striping or the like results in truely spectacular images of Mars topography.

We'll see what we might make from non-imaging instruments that are interesting, when we have a payload list and some instrument details.

Well, I can give you the full instrument list (although not in much detail):

(1) Multi-channel microwave spectrometer (for very deep temperature, water vapor and ammonia profiles).

(2) UV imaging spectrometer (another version of the "ALICE" on Rosetta and New Horizons).

(3) Magnetometer

(4) Plasma detector ("JADE", or Jovian Auroral Distributions Experiment).

(5) Energetic particle detector

(6) Plasma wave detector

(7) Camera

Plus the radio science experiment -- which is actually the most important one on Juno, with the possible exception of the microwave spectrometer and magnetometer, given its ability to make gravity-field measurements so precise that they will settle both the question of whether Jupiter has a rocky core, but even detect the convection currents from very deep winds.

Nothing in there for images, except for the camera itself and ALICE (plus whatever maps they get out of the microwave instrument). As I say, this is a very important mission scientifically -- giving us our deepest look yet into Jupiter's innards -- but it won't have much charm for nonscientists.

I would have thought / hoped the next Jovian mission would have been a Europa orbiter. This is one of the few places besides Mars that holds any prospects for life. Whatever happened to Nasa's "follow the water" mantra. The Juno mission just doesn't stir up any passion.

Hopefully Juno wont have an umbrella style high gain antenna like Galileo!

Seriously, it will be great to see movies of Jupiter's weather and cloud patterns, something Galileo could not do because of the high gain antenna issue.

i am also surprised that a Europa mission was not selected. Must have been too much money.

I could certainly imagine that life might exist deep in the Jovian atmosphere. A bit hard to get at though.

tty

Actually, I'm glad to see a mission that does tow that line, astrobiologically speaking. In terms of a Europa orbiter, such a mission would be a flagship, billion-dollar class mission, a step up in pay scale from the New Frontiers missions. Believe it or not, I am fully behind the Europa orbiter, once I started thinking of it as a two-year Io mission with a 30-day extended mission in Europa orbit.

Well, the Decadal Survey recommended -- and the new NASA Solar System Roadmap document backs again -- a Europa orbiter; but it's too expensive to be an NF mission. Instead, the Roadmap report calls it a "small Flagship" mission -- that is, in the $700 million to $1.5 billion price range -- and strongly recommends it for a launch in 2014, maybe even with a small Europa lander added. Hopefully they'll finally stop screwing around and fly the damn thing, now that O'Keefe's JIMO fairy tale has been taken back off the table. (Rumor has it that, due to his engineering ignorance, he was bamboozled into backing that grotesquerie by his pro-nuclear brother.)

Indeed, the Roadmap recommends two more small Flagship missions after that at 5-year intervals -- the first probably being a Titan Explorer (an aerobot to repeatedly sample the surface looking for organics, and relaying its data directly back to earth without a Titan orbiter), and the second being a Venus Explorer (some kind of long-lived surface vehicle using the temperature-resistant electronics that will hopefully be available by 2024 -- maybe a surface rover as the report recommends, but maybe instead a repeat-landing aerobot like the Titan mission). Then at some point in the 2025-35 period, it recommends one really big Flagship mission in the multi-billion dollar class, with several possible targets.

Jason is likely to be disappointed if he thinks of the Europa orbiter as "a 2-year Io mission with one month in Europa orbit". The plans for it, which have long ago been worked out in detail, call for it to make repeated flybys of Ganymede and Callisto during its 2-year orbital tour before settling into Europa orbit -- but NOT to get any closer to Jupiter than Europa, in order to minimize its radiation dose. The plan now is not even to have it make a close approach to Jupiter at its initial arrival -- instead, it will approach at Ganymede's distance and make a Ganymede flyby to help brake itself into Jovian orbit (rather than using Io for that purpose, as Galileo did).

I never thought it would actually flyby Io, given the radiation concerns. But for Io, the key need is not necessarily high spatial resolution images, but high temporal and spectral resolution observations. So even consistent observations over a 2 year span can prove VERY useful for Io science.

I always thought JIMO sounded too good to be true. I hate it when I'm right about that kind of stuff.

Are there any informed critiques of JIMO on the web? I just figured it wasn't going to happen because of the everyone-gets-a-pony aspect, as opposed to actually knowing anything.

Not a detailed critique, but here is what Mike Griffin said to Congress about JIMO

LOL! Thanks, Redstone. Those are some good details.

BESIDES all that, there was one other major problem that Griffin didn't mention and which would unique to JIMO among all NEP missions: the fact that it would simultaneously have had to be designed with new radiation-proof electronics for its Europa-orbiting mission. Jupiter's charged-particle radiation presents an entirely different kind of problem for electronics than the neutrons emitted by a nuclear reactor, and in any case the radiation from the latter -- on the end of a long boom, and with its own shield -- would be trivial in relative dosage anyway. Indeed, Jupiter's own radiation would seriously complicate the design of the reactor's own control electronics. This whole big problem, as I say, was unique to the JIMO proposal, and is further proof that it could have been advocated only by someone who didn't know anything whatsoever about actual engineering and could thus get suckered by dishonest underlings -- namely, O'Keefe.

I was just pondering that concept. My idea, though, is even more ambitious: A Europa sample return mission that utilizes multiple flybys of Jovian moons in order to slow down enough to make a soft landing on Europa. A core sample would then be taken, which would be segmented into shorter pieces, and then launched into Jovian orbit, where it would be picked up by a larger orbiter. This would then conduct many more flybys in order to reach Jovian escape velocity. It would finally enter a solar orbit that would return it to Earth. The purpose of all the gravity assists, of course, is to use as little fuel as possible.

The Juno instrument selection looks quite "reasonable".

Camera, for cloud tracking and atmosphere structure,

A basic fields and particles instrument set covering all essentials. Particle data's necessary to study magnetosphere dynamic effects on the magnetic field, to better separate external forcing from internal magnetic field sources.

UV spectrometer will probably have dual uses of upper atmosphere structure, composition and dynamics, and detailed imaging studies of the auroral oval and airglows. Together with the fields and particles data, this maps the magnetic field down to the atmosphere top.

I'm more than a little surprised there's no imaging infrared instrument or mapping spectrometer. Maybe the camera system's going to include a mid-infrared (1 micromter to 5 micrometers) detector. The 5 micrometer band gives the deepest pemetration into hotspots and the like.

From Earth, we've crudely mapped microwaves from Jupiter's disk. That's where we get the deepest electromagnetic spectrum remote sensing of the atmosphere. Essential instrument.

The original concept for a Europa Orbiter was not a multi-billion dollar, nuclear propulsion behemoth, but rather a <1 billion scout mission with radar and imaging capabilities. The proposed mission had overwhelming support from both the public and scientific community.

http://www.planetary.org/html/society/pres...vey_results.htm

http://www.planetary.org/html/UPDATES/Pluto/plutoeuropa.html

It's only because of the shortsighted, politic driven decision making that that this mission has been "on again - off again" so many times.
Fortunately, NASA is not the only game in town any more. Maybe we will see an ESA Europa mission while NASA is trying to find its way.

http://sci.esa.int/science-e/www/object/in...fobjectid=35982

I don't think getting to Europa is the biggest hurdle to overcome. I think one of most difficult challenges will be to get there without contaminating the moon with terrestrial organisms. I don't think that it is possible to completely sterilize a spacecraft and allow it to impact the moon. Enough fuel would have to be brought to allow it to leave the orbit of Europa when the mission is over and de-orbit into Jupiter the same way that Galileo did.

My apologies for getting OT.

I don't think getting to Europa is the biggest hurdle to overcome. I think one of most difficult challenges will be to get there without contaminating the moon with terrestrial organisms. I don't think that it is possible to completely sterilize a spacecraft and allow it to impact the moon. Enough fuel would have to be brought to allow it to leave the orbit of Europa when the mission is over and de-orbit into Jupiter the same way that Galileo did.

My apologies for getting OT.

[/quote]

I don't think the crashing of Galileo to "protect" Europa was worth it. I am extremely skeptical of the idea that the place might have life, and I think NASA's hyping of the idea distracts from the truly interesting aspects of Europa and the Jovian system.

Most of the P.R. talk on crashing Galileo into Jupiter reffered to the planetary quarantine problem. They barely discussed the real reasons for the end of mission. 1.) The spacecraft was running out of orbit trim propellant. 2.) Radiation damage was making the spacecraft "sicker" and sicker. Things were progressively failing, going intermittant, flakey, etc. 3.) $$$$$... The mission was expensive to operate and track because of the enormous Deep Space Network effort to return a trickle of data from the omin antenna, after the main antenna failed to open.

But essentially, the spacecraft was dying.

I hear the same BS about evil NASA "killing" the Magellan Venus radar orbiter; but the spacecraft was literally falling apart when it was intentionally lowered into the atmosphere. Thermal cycling was causing the solder joints on the solar panels to break, and the spacecraft's was progressively and rapidly losing power at the end.

- 2010: Odyssey -
Just kidding!

Before I kick the bucket I wanna see Full global mapping and a confirmation of a global ocean. < I'm Pretty sure it's there, I just wanna say Na Na Na Poo Poo to the Naysayers

[quote=tedstryk,Jun 4 2005, 12:27 PM]
I don't think getting to Europa is the biggest hurdle to overcome. I think one of most difficult challenges will be to get there without contaminating the moon with terrestrial organisms. I don't think that it is possible to completely sterilize a spacecraft and allow it to impact the moon. Enough fuel would have to be brought to allow it to leave the orbit of Europa when the mission is over and de-orbit into Jupiter the same way that Galileo did.

My apologies for getting OT.

[/quote]

I don't think the crashing of Galileo to "protect" Europa was worth it. I am extremely skeptical of the idea that the place might have life, and I think NASA's hyping of the idea distracts from the truly interesting aspects of Europa and the Jovian system.

[/quote]

That possibility ain't "hyping": the science community itself has taken the idea extremely seriously for a couple of decades. Europa, after all, has lots of liquid water -- something which Mars has in tremendously more limited amounts.

And there's another factor, which I haven't seen mentioned in print although the scientists I've mentioned it to seem to agree: even if we find proof of present or fossil Martian life, we may have hell's own time proving that it didn't just descend from ancient Earth germs blasted to Mars via meteorites from Earth during the Solar System's earliest days (or, for that matter, vice versa). On the other hand, if we find Europan life, the odds will be overwhelming that it's native -- which means, since two worlds in a single Solar System will have separately developed life, that we'll know life must be common in the Universe as a whole, rather than being just an extremely rare chance development that happened to make one of its rare appearances in our own Solar System. For this reason, I have for years regarded the search for Europan life as MORE important scientifically than the search for Martian life.

As for the danger of contaminating Europa: the science community takes that very seriously, too. See the 2000 report by the National Academy of Sciences ( http://www7.nationalacademies.org/ssb/europamenu.html ) -- which points out that, since Europa has a unified liquid-water ocean, terrestrial microbes could spread all over that world far more quickly than terrestrial microbes could if they got loose on Mars. Proper sterilization of Europa spacecraft is extremely important, even given the fact that Jupiter's savage radiation environment will give us a lot of help in that regard.

That being said, providing Europa Orbiter with enough fuel to break back out of Europa orbit is simply impractical -- it will be hard to carry enough even to put it into Europa orbit in the first place. This is a difficult mission. We will, instead, just have to make sure it's properly sterilized (as we'll have to do in any case with all Europa landers).

Yep -- the Space Studies Board had done a detailed appraisal for NASA years earlier of just how much of an extended mission for Galileo was scientifically cost-effective. They ended up going for the most ambitious possible plan, except that they rejected the idea of trying to photograph Amalthea during its flyby on the grounds that the craft would almost certainly develop serious radiation collywobbles during that period anyway (which, indeed, it did). They did decide to add an imaging plan for its final Io flyby (something Jason Perry privately worked like hell to encourage) -- only to have that also ruined by a radiation reset of the sort that fouled up almost all of their Io flybys to varying degrees.

There is no way you can say that NASA threw away this spacecraft wastefully -- I'm amazed that it lasted as long as it did. (I'm even more amazed that they were able to squeeze so much valuable science out of it after the HGA disaster -- when I first heard about that in 1991, I figured that all of the mission except the entry probe was dead.)

While the new Solar System Roadmap (or, rather its first draft -- it's about to undergo some minor revisions) has just been yanked back off the Web (along with all the other new Roadmaps) by NASA within a few days of being put there, I copied them all first. Two things about the Europa Orbiter:

(1) It will actually be the first of a new cost class of Solar System missions -- which were called "Intermediate" missions at the first meeting of the Roadmap committee when I attended it, but are now referred to as "Small Flagship"
missions. These are missions in the $700 million to $1.5 billion class. One thing that killed Europa Orbiter last time was the fact there was a $1 billion cost cap on it, and JPL concluded that it simply could not be done -- even in stripped-down form -- for less than about $1.2 billion. (The next two Small Flagship missions -- spaced at intervals of about 5 years -- will be to Titan and Venus.)

(2) One thing which the science definition team recommended strongly for JIMO could perhaps end up flying on this much smaller chemically-propelled mission: a small Europa lander weighing only a few hundred kilograms. It would certainly further complicate the mission -- but, given the very long intervals between Europa missions, we may well want to jump to this phase as fast as possible. (Exobiologist Jack Hunter once told me bitterly: "I'll be in a wheelchair by the time they land on Europa.") The Roadmap mentions it briefly as a possible addition -- and there was a very detailed design study done last year ( http://dosxx.colorado.edu/%7Ebagenal/OPAG/...port_Final2.pdf ).

It would use a flat-out full soft-landing system rather than airbags or other shock absorbers, on the grounds that the latter are just too heavy. Its two mandatory instruments would be a seismometer (to probe the thickness of the ice layer) and a mass spectrometer hooked up to a system for separating out various organic compounds (probably using liquid rather than gas chromatography) from the ice. The next two priority instruments would be a magnetometer (for more data on the ice layer thickness), and a surface camera -- that's probably as much as they could cram onto it. But the catch is whether they can design a lightweight sampling system for the mass spectrometer that could penetrate deep enough into the ice to get below the upper layer of Europan regolith where any biological organics have been unrecognizably scrambled by Jupiter's radiation -- probably a couple of meters. If they can't, I don't think a piggyback lander is worth flying.

But, with a lander or not, I think Europa Orbiter is finally definitely going to fly -- quite posibly as a collaboration with the ESA, which has recently officially declared itself very interested in such a teamup. NASA has finally been forced to get serious about this mission, as they finally were with the Pluto probe.

Juno was deliberately created as a fusion of the three previous Discovery-class Jupiter mission concepts -- INSIDE Jupiter, the JASSI flyby, and the Jupiter Polar Orbiter -- and in fact the three proposal teams united for this mission. (I will never forget the Solar System Exploration Subcommittee meeting I once attended at which the PIs for INSIDE Jupiter and JASSI kept pulling me aside into corners to whisper derogatory things about each others' missions and encourage me to write them.) But if Juno is descoped, the instruments to go will be some of those associated with the magnetospheric investigations of JPO -- ALL the goals of the other two missions could be achieved with only two instruments: the magnetometer and the microwave spectrometer. The camera, according to Bolton, is the lowest-priority of the lot -- although I certainly intend to grill him more now on its capabilities, and on the possibility that they might be able to incorporate one or two flybys of Io and/or Amalthea (probably during an extended mission).

The other real difference between potential Martian and Europan life is that Martian life, if it exists today, is likely to be very, very simple -- bacteria at best. Whereas if Europa has developed life, there are fewer reasons to believe that it would *have* to be very simple. With an aquatic environment and enough heat from within the moon's rocky core, Europan life has no greater obvious evolutionary limits than Earth's sea life does.

As much as finding fossilized bacteria, or even live bacteria, on Mars would prove a point and be interesting in and of itself, it wouldn't give us a whole lot of data on how life might develop outside of Earth's influence. Multi-cellular organisms (or their equivalent) in Europa's oceans would demonstrate how life might be able to organize itself in different ways to those we see on Earth. For example, would genetic encoding be DNA-based? Or has Europan life found different ways to organize, evolve and propogate?

I think the most boring thing we could possibly find on Europa would be -- fish. Regular old fish, with scales and gills and DNA and everything. But it would sure hint at some common ancestor to life on both worlds, wouldn't it?

My bets are on truly alien life forms swimming in Europa's oceans, whether they look like fish or not.

-the other Doug

Yes, but if it is small and simple, it is unlikely to be cut, given its PR value - There is no point in making cuts that don't save much money, weight, or power unless you are really desperate.

I hope so, but I am biting my nails considering it seemed quite definite in the late 1990s...lets hope it doesn't get tied to a political push again.

Thanks for all the info you provided. I hadn't heard about a Nasa/ESA cooperative effort for a Europa orbiter That's great news I hope the plans don't get stalled.

If leaving a Eurpan orbit is not practical, I guess the next best thing to do is leave it in orbit and let the intense radiation sterilize the craft. Once in orbit, how long would a spacecraft remain in an orbit around Europa? With little or no atmosphere, I would think a spacecraft would remain there for quite a few years. Are there other factors that would cause the orbit to decay such as tidal forces or resonant forces from the other moons?

I read the link that you provided from The National Academies on Preventing the Forward Contamination of Europa. I'm not sure if I share their optimism on the ability to satisfactorily sterilize a spacecraft. Even by their admission, a spacecraft will never be 100% free of biological organisms or spores, but only reduced to an acceptable level. I remember the surprise and disbelief when a piece of the Surveyor lander was brought back and Streptococcus bacteria were found to be still alive inside the camera. They were exposed to the vacuum of space, zero moisture, extreme temperature swings (night and day on the moon are 14 days long) and they were there for almost three years.
The biggest fear would be if the spacecraft missed it's orbital insertion target (i.e. Mars Climate Orbiter) and impacted directly into the moon. Without an atmosphere to slow it down, it would impact hard and pieces would most likely be buried under a protective layer of ice. I am still 100% for a Europa orbiter, but I think that we have an obligation to keep the risk of contamination as close to zero as we can. At least until we can confirm if any life currently resides there.

Three miscellaneous comments for this thread, from the concrete to the fanciful:

1) Orbits around Europa are very unstable due to the presence of other gravitational sources in the vicinity (the same is true of the Moon, but of course, Jupiter is much pushier than Earth gravitationally). So whenever the craft dies, it will not be long in impacting Europa's surface. Months, not years.

2) It is not believed that a europan ocean would have enough energy to support advanced life. That is surely somewhat speculative, but take that for what it is. The suspicions lean towards bacteria or nothing.

3) If (2) were wrong, the presence of, eg, fish would not point to a common origin. Earthly biota have reinvented key phylogeny properties many times. For example, "tree"ness has evolved very many times, on separate family branches. I think we can be dead certain (NPI) that fish would not make the ride from/to Earth to/from Europa on meteorites, in any form whatsoever.
If we do find life elsewhere, macroscopic resemblance would be a much less convincing evidence of common origin than molecular resemblance. Chirality to start with, use of the DNA codons vs. RNA codons in equivalent roles next. Someone with biology training past ninth grade could comment on others.

While a NASA only Europa mission may not be "on" right now, here's another Griffin quote made to the press on May 12:



Sounds like a NASA mission is still on the cards, but we just need to wait a while. Remember Griffin is focussing on the manned program right now, the JUNO announcement notwithstanding. Once the ISS and CEV plans get settled in a few months, I'd expect Griffin to turn to the long-term detail of the space science program.

Some comments on life on Mars (and elsewhere) and on Surveyor 3:

Life isn't divided into success and failure by 'simplicity' and 'complexity' - the only 'success' is survival of the organism through it's offspring (so human intelligence and fecundity may well not be good success strategies). The sophistication of 'simple' Martian/Europan life may not be obvious to a big game hunter, but a microbiologist might well disagree. Let's not get hung up on macro-organisms!

And sadly, there's a persuasive view of the Surveyor 3 camera which suggests that the bacteria found within it were due to laboratory contamination, so the jury has to still be out on the survival of spores etc in space.

Considering the early bombardment history of the planets, plus the recent claims of an equally early warm and wet Earth I'd be unsurprised to discover that life on Earth and Mars share a common ancestry (or are at least distant cousins, survivors of crustal reformatting by giant impacts and natural interplanetary flight).

If and when we ever see a substantial industrial base on the Moon, then that's the place to look for meteorites bearing the early signs of life - or maybe even smaller bodies, like asteroids, Phobos and Deimos, comets...

Well, forget for a moment the sibling (parent) rivalry between Jupiter and the other worlds near it.
What we're talking about here is Jupiter -- one of the three most central planets to space exploration -- finally getting its Pioneer Venus, finally getting its Mariner 9. Among the worlds that have had orbiters (preCassini), one that is totally unique in structure and atmosphere. And with Galileo's Jupiter science having been a mere trickle, one that has been seen more like a world that's received six flybys than has ever been the subject of an orbiter's science in the way that Mars has received six, and Venus several (mainly Soviet, but two American).
It's got an atmosphere that is in some ways (thick water clouds, for one; sweeping storm fronts bearing rain) more earthlike than either Venus's or Mars's. A structure which is totally unlike that seen in the inner solar system. And note that Cassini is not giving Saturn the look that Juno would give Jupiter. Cassini's closest approach to Saturn already has taken place, and it wasn't even looking at the planet. Saturn's rings are both a barrier for close approaches and a factor that neutralize the particle environment that we want to see at Jupiter. Remember, Jupiter is our best analogue to most of the extrasolar planets we've discovered, and knowing it better could prove essential, obliquely, to our efforts to find earthlike planets sharing those systems with giant neighbors.
I don't think the first *real* Jupiter orbiter is a low-passion mission at all. With its camera a minor player, it may rank low in terms of (intended) eye candy, but planetary science is a forensic science, and fingerprints may seem less exciting than photos of a corpse, but they can be more telling about the history.
I'm excited about Juno -- even eye candy should be forthcoming. But I'm pretty curious about what's beneath the hydrogen. Whether it's 1 earth-mass or 30 earth-masses may have little visible effect at the surface, but the result will tell us a lot about origins. And given that the source of magnetic fields remains a bit of a mystery (eg, Mercury's; the large differences between those of the giant planets), more information on that matter is going to be welcome as well.

I think the six-flybys analogy is a good one (seven if you count Ulysses Jupiter Distant Flyby a year or two ago which did yield some interesting particle and fields data, particularly with regards to dust from Io) in terms of data return, although it was over an extended period of time, so for things such as Io coverage, it at least had a long temporal baseline. I see it as a series of mini-flybys. I do hope that an Amalthea flyby can be squeezed into Juno. It will be penatrating in that far, and I don't see another spacecraft doing that for the forseeable future (I don't think it would be good to even risk an Io mission). It is a shame Galileo didn't take remote sensing data. Given its illness and how badly it got zapped however, had it been making turns to do imaging at the time of the encounter at first Io and then Amalthea, it would likely have at least safed, costing us the data on the near-Amalthea particles, a lot of particle and fields stuff, and we might have lost the spacecraft all together. The budgetary issues non withstanding, I would have loved Galileo images close to Amalthea, but I am skeptical the spacecraft could have pulled it off. I have been working on some of the images Galileo took, and it is a very interesting world, especially given the new shape-model release. I have worked hard on the high resolution E26 image, and you may have seen my result - it is faux-super-res, created by stacking various resamplings and processings of the same image. It creates a relatively sharp image despite oversampling, although it doesn't truly increase resolution. I also tried to correct overexposure in part of the image.

Also, have worked on the only three Galileo color images of Amalthea, taken during the primary mission. I created color images using the various filter combinations available (the E4 data had a fourth filter available, but I didn't use it for color). I also used all available images (3 for G2 and C3, 4 for E4, although the E4 data was so distant it really wasn't worth it) to creat super resolution black and white images. I then overlaid the color data on these. Here is the result:

I vaguely remember reading somewhere that Juno will be spin-stabilized, probably making it difficult to obtain high-res images of satellites like Amalthea or even Io during fast flybys. Or maybe I'm confusing Juno with something else (Inside Jupiter/JASSI etc.). Does anyone know if it will be spin-stabilized ?

Yeah, it will be -- which will certainly interfere with any imaging during a flyby, but would not make it impossible (or so low-quality as not to be worth the effort). Again, I intend to contact Bolton for more on all this in the very near future.

On that last score I note that someone wrote in a recent scientific paper titled To Land on Europa:


Should that prove to be the case, if you want to be able to drill even deeper ("a couple of meters") I guess that would mean an even bigger increase in the lander's weight.

dvandorn wrote:

"I think the most boring thing we could possibly find on Europa would be -- fish. Regular old fish, with scales and gills and DNA and everything. But it would sure hint at some common ancestor to life on both worlds, wouldn't it?"

Its true that active swimmers would have to be streamlined to travel efficiently in water, but no or extremely little oxygen would mean no gills and active swimming less likely. (No photosynthesis possible under a mile of ice).

If there any life on Europa its more likely to be colonies of organisms gathered around warm springs getting their nourishment from chemical processes, what shape they might have im not qualified to even speculate about. The big question is if liquid water and volcanic heat is enough to get life started.

-"-

As for sampling and investigating deeper down: The idea of a robot that melts itself down to reach any possible ocean beneath the ice is a clever idea, but its not even on serious consideration so I wont see it in my lifetime.

(GOING STILL FURTHER OFF TOPIC, HERE)

Back in the salad days before we knew so much, it seemed possible to melt through the ice. But two compounded difficulties pretty much kill that idea. One, the ice is much deeper than we might have hoped. 20 km seems to be the direction that the evidence is pointing. Then, the factor that makes that especially lethal is that if the ice has any impurity at all, melting through it would cause the impurity to accumulate at the bottom of the hole, eventually creating a mass of salt or somesuch, which heating to 10C would not make go away.

Enceladus could stand in as a new arena for the exact same hopes. Cassini's early imaging seemed to deflate those hopes, for, although Enceladus showed young surface, it also showed considerable relief, which means the ice must be relatively thick (even when you allow for the very weak gravity). But, the last flyby of the south pole showed "tiger stripes" analogous to Europa's triple bands, and nonimaging instruments indicate that H2O seems to appear in Enceladus's vicinity at a considerable rate -- these results may combine to indicate that live geysers exist at high latitudes, which would provide a possible point of axis for a Enceladus Underwater Explorer (???). Not to help Myran too much, though -- I don't see that happening in our lifetimes, either!

They are sending a Probe to Jupiter and according to this article Europa Ganymede and Callisto will not be studied?!?!


EUROPA should be Number 1 on the priority list.


I'm so upset by this article. http://www.space.com/searchforlife/seti_juno_050609.html

FWIW, a wee writeup at Astrobio.net, and the ever-popular "artist's conception" of the spacecraft. Solar!

For some reason, I can't load that article. I get a blank screen.

But, the reason why Europa has been shortchanged is organizational fumbling of a high degree. I can remember when Pluto and Europa were competing for a launch date that would have already taken place, and the winner of the competition was... neither.
Europa Screw-up #1 was to bundle three bizarrely dissimilar missions under a single planning structure (a Europa orbiter, a Pluto flyby, and a solar probe), even though the three had little in common except they were spacecraft that would not land anywhere.
Europa Screw-up #2 was to propose JIMO, aka Mission Impossible, so that we had to wait until it fell back to the ground when the gravity of common sense had counteracted the upward momentum of bad politics. JIMO was meant to be the sugarcoating on an expensive nuclear propulsion research program, which was motivated by a way to drain NASA funding for a quasi-military project. JIMO's math never worked, and it was the brainchild of people who don't care if the math works before they sic some government agencies on a job.
As far as Europa was concerned, the JIMO proposal was an X year delay, with X being mercifully hastened by O'Keefe's departure.

As it turns out, a few years ago was probably too early to have commited to a Europa mission design. It's taken a while for Galileo results to be digested, and even now, I think a Europa exploration architecture has to be considered very carefully. We're playing 20 questions with Europa, where each question costs a billion dollars or so. The best next mission to Europa might not be the best mission if we were only sending a total of one. We've got to consider what the next mission would be depending upon the first one, and then plan to make absolutely sure that no mission asks a yes/no question where the answer is, "Neither yes nor no. That's the wrong question."

It's clear that Juno is a good Jupiter mission and it can go ahead and take place. Waiting for the Europa situation to clarify before sending a mission to Jupiter is like waiting to figure out next year's taxes before eating breakfast. The two things are unrelated. Europa shouldn't preempt a good Jupiter mission any more than Europa should preempt a good Mercury mission.

Another factor to consider is that a decent Europa Orbiter mission probably can't be done as a New Frontiers mission. Juno will allow some fundamental Jovian science to be accomplished. And it is one of the most productive missions that can be accomplished at Jupiter on such a budget.

Part of the problem is that *any* Europa orbiter mission is ***HARD***.
It takes a tremendous amount of Delta-V (velocity change) and only some of that can be done by gravity assist flyby's of the moons. Add to that the radiation environment that was crippling and killing Galileo as the extended missions proceeded, but on a continuous basis as you get in toward Europa, rather for only the periapsis pass part of month long orbits. You need extra radiation hardened electronics, AND massive shielding. The original Europa orbiter mission was nuked as it's projected costs passed some 1.2 billion, heading for and past 1.5 billion <or so>, when it was supposed to be an under 1 billion $ mission.

Good management and realistic objectives will help tremendously, but they won't solve the basic problem. It's a damn hard mission.

Even with Galileo type flybys would make me happy. From the sounds of the space.com article Juno will not get that far out?!