Deep space missions are often mainly big wastes of money. NASA wasted many billions on the Apollo program landing astronauts on the lifeless rock that is the moon. Nothing of any real scientific importance was discovered. Now NASA wants to send people back to the moon. Why would someone want to land more people on this lifeless rock, about the dullest place imaginable?
NASA has a page trying to justify the Artemis project, but it fails to make any convincing case for it.
When you click on the links shown above, you get only the skimpiest statements that sound like vaporous PR fluff. Clicking on the "Discovery" link merely gives you this sentence: "With Artemis, we’re building on more than 50 years of exploration experience to reignite America’s passion for discovery." No substance there. That "more than 50 years of exploration experience" includes previous trips to the moon, so why bother going again? Clicking on "Economic Opportunity" merely gives you this sentence: "Artemis missions enable a growing lunar economy by fueling new industries, supporting job growth, and furthering the demand for a skilled workforce." This is pretty much a "welfare for rocket builders" rationale, a "big handout" to wealthy corporations. That's no persuasive reason. Clicking on "Inspiration for a new generation" merely gives you this little piece of PR fluff:
"We will explore more of the Moon than ever before with our commercial and international partners. Along the way, we will engage and inspire new audiences – we are the Artemis Generation."
There's no need to explore the moon with astronauts. The moon has nothing interesting, and has already been thoroughly mapped with unmanned probes and telescopes. The prediction about audiences being engaged seems dubious. During the last two moon landings in the early 1970's, TV audience ratings plummeted. People quickly lost interest in moon landings after a few successful moon landings had occurred.
It is not just Americans who can waste billions on space boondoggles. The Europeans are also pretty good at that. There's proof of that in the recently launched JUICE mission. Having a price tag of 1.7 billion dollars, the JUICE mission will go on the dumb mission of orbiting Jupiter's moon Ganymede. Below is the "dull as dishwater" surface of this boring object:
Credit: NASA
Why would someone want to send an orbiter to orbit Ganymede? Does anyone think that instruments could detect life on the surface of Ganymede? No, every one agrees that such a thing is impossible. Ganymede has no appreciable atmosphere, and its surface temperature is estimated as being from -297 to -171 degrees Fahrenheit, way too cold to allow for life.
Some think that very far underneath the surface of Ganymede is a liquid ocean. There is no good evidence for such a thing. A NASA page describes some scientist trying to find evidence of an ocean underneath Europa, and we read this strained not-very-convincing talk:
" 'I was always brainstorming how we could use a telescope in other ways,' said Saur. 'Is there a way you could use a telescope to look inside a planetary body? Then I thought, the aurorae! Because aurorae are controlled by the magnetic field, if you observe the aurorae in an appropriate way, you learn something about the magnetic field. If you know the magnetic field, then you know something about the moon’s interior.' If a saltwater ocean were present, Jupiter’s magnetic field would create a secondary magnetic field in the ocean that would counter Jupiter’s field. This 'magnetic friction' would suppress the rocking of the aurorae. This ocean fights Jupiter's magnetic field so strongly that it reduces the rocking of the aurorae to 2 degrees, instead of the 6 degrees, if the ocean was not present.' "
So they didn't see any ocean with a telescope. All they saw was an aurora (some glowing gas), and then some scientist wanting to believe there was an ocean underneath the surface of Ganymede did some kind of roundabout strained-logic chain of reasoning involving dubious assumptions about tenuous auroras and magnetic fields, which caused him to say he had come up with something maybe hinting there was an ocean far underneath the surface of Ganymede. We should always be very suspicious when we read dubious-sounding logic like this. There are any number of reasons why you might have got the aurora observation from Ganymede without there being any liquid ocean underneath the surface of Ganymede. The fact that you have a model that postulates unseen thing X could explain phenomenon Y does not mean unseen thing X exists.
Here the never-observed liquid ocean of Ganymede has the same status as never-observed dark matter. You can use dark matter to try to explain why stars orbit around the center of the galaxy the way they do (the main reason why dark matter is postulated), but that doesn't show that dark matter exists. There are other ways of explaining why stars orbit around the center of a galaxy the way they do, without postulating any dark matter. And whatever aurora observations were made involving Ganymede can be explained in various ways without postulating any liquid ocean below the surface of Ganymede.
In the reasoning quoted above, Saur sounds rather like someone who detects that his indoor plant has died, and who reasons that this probably occurred because it got very cold indoors, and that it must have got so cold indoors because a ghost passed by. That kind of "pinball machine" reasoning is not very convincing. In a scientific paper on this topic (co-authored by Saur), entitled "The search for a subsurface ocean in Ganymede with Hubble Space Telescope observations of its auroral ovals," the authors sound like people following a "keep torturing the data until it confesses" approach, rather than any straightforward, reproducible analysis method. Here is an excerpt showing just a bit of the arbitrary data fiddling that was occurring:
"For a quantitive analysis of the observed auroral fluxes, we first remove the background emission due to dark noise and other sources. For this purpose we average the fluxes in rows above and below the OI 1356 Å image to determine the background fluxes and then remove this flux from the OI 1356 Å image. We use solar spectra measured by the Solar Extreme-Ultraviolet Experiment (SEE) on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission [Woods et al., 2005] for the particular days of the observations in order to model the solar reflected light from the surface of Ganymede. For determining the albedo, the long-wavelength image of the observations (λ= 1413 Å to 1586 Å) is used. We find a geometric albedo of 0.017 ± 0.003 for visit 1 and 0.019 ± 0.003 for visit 2 on the leading side. The albedo values of this study are similar to values for the albedo on the trailing side of 0.023 ±0.002 derived from fluxes near 1400 Å by Feldman et al. [2000] from HST/STIS observations and an albedo of 0.026 ±0.003 derived by Hall et al. [1998] from HST/GHRS measurements of the reflected C II 1335 Å multiplet. Due to a lack of knowledge of the spatial structure of the FUV albedo, we assumed similar to previous studies that the albedo is spatially constant. We note that modifications of the albedo values have a negligible effect on the derived rocking angles of this analysis. The modeled reflected flux is then convolved with the point spread function (PSF), which we obtained with the TinyTim simulation software package from the website tinytim.stsci.edu [Krist et al., 2011]. The PSF has a Gaussian structure near the central pixel and power law wings at larger distances from the central pixel similar to the kappa-PSF(κ,γ) [Saur et al., 2011], which is identical to a Lorentzian profile for κ=γ=2. The fluxes of the reflected light are then finally removed from the observed OI 1356 Å flux, and the images are rotated with Jupiter's north pointing upward."
And on and on the paper goes, telling us about the details of its extremely arbitrary and convoluted analysis pipeline, which sounds like a bleeding-edge "make it up as they went along" affair (the paper not being a pre-registered paper which stated an exact procedure that would be followed before data was gathered). For example, we hear of a long complicated equation (the use of which is never justified) that was applied as a "smoothing filter" four different times. It sounds rather like the authors were following an approach that can be summarized as "keep torturing the data until it whispers in the faintest voice that maybe Ganymede has an ocean." This "give me an inch, and I'll take a mile" kind of analysis smells like a very tenuous and gossamer foundation on which to be basing a 1.7 billion dollar mission.
A page of the European Space Agency that has launched the JUICE mission misleads us on this topic, by giving us the following obviously defective language:
"The Galileo spacecraft's measurements of Ganymede's magnetic field suggested there could be a subsurface layer of salt water, which unlike ice is a good conductor of electricity. However, this evidence was not conclusive because of the complex interactions between the magnetic fields of Jupiter and Ganymede. More recent observations of Ganymede's auroras made with the Hubble Space Telescope further hinted at the existence of the under-ice ocean. As such, scientists now have firm evidence that Ganymede, like Europa, conceals an ocean under its icy shell, one that may contain more water than all surface water on Earth combined."
Did you notice the ridiculous transition here? Mentioning a mere suggestion that there could be an ocean underneath the surface of Ganymede, and a mere hint of the existence of such an ocean (a strained piece of reasoning that was no more than a very faint hint), the writer says this is "firm evidence" that such an ocean exists. A suggestion and a hint do not add up to firm evidence. There is no firm evidence of such an ocean. And no one has shown that Ganymede probably has an ocean under its surface.
But suppose there is a liquid ocean far underneath the surface of Ganymede. Could the JUICE mission ever verify there was life in such an ocean? It could not. Buried far underneath the surface of Ganymede, life in such an ocean would not be detectable by the JUICE mission. So we have a mission costing 1.7 billion dollars that will have no chance of discovering life. About the only good of the mission is that it will help scientists such as Saur have a better idea of whether they are on the right track by speculating about the existence of an ocean underneath the surface of Ganymede.
The same European Space Agency page misleads us with a section entitled "Searching for Biosignatures." Such a heading suggests some ability to detect life if it existed in an ocean of Ganymede. The JUICE mission will have no such ability. The section merely mentions this: "Observations at various wavelengths will allow astronomers to study non-water-ice material to determine the distribution of biologically essential elements—such as carbon or oxygen—and other important elements—such as magnesium and iron—on the planetary body." That is not searching for biosignatures. Detecting carbon amounts and oxygen amounts is not finding a signature of life.
The European Space Agency page has misled us in two important ways: (1) by claiming "firm evidence" of an ocean underneath the surface of Ganymede, when no such evidence exists; (2) by trying to create the impression that the JUICE mission will have some ability to detect life that could exist in such a hypothetical ocean, when it will have no such ability. A story in the Gusardian shows how such misleading language is being passed on by the press. The Guardian story is entitled "Juice mission blasts off to Jupiter to look for signs of life." Later the same story tells us the opposite: "Juice is not equipped to detect life itself." And so it is with story after story in the science press, with the left hand of the story contradicting the right hand. For the headlines of stories in the science news, the rule is pretty much "anything goes." A story on www.forbes.com confesses that "it’s not suspected that life exists on Ganymede."
There's one good thing I can think of to say about the JUICE mission: it apparently did not contain any plutonium for its power source, and so human lives were not greatly risked when the mission was launched (as they were by multiple NASA plutonium-powered deep-space missions that risked many thousands of deaths from plutonium poisoning if a launch had failed). From a scientific standpoint, the JUICE mission is a ridiculous boondoggle, a misuse of funds. 1.7 billion dollars have been spent mainly so that scientists such as Saur can get a little better idea about whether their speculations about an ocean underneath the surface of Ganymede are correct. Even after the mission is completed, we still will not know for sure whether such an ocean exists. You can't tell whether a subterranean ocean exists by studying either aurorae or magnetic fields. There is no chance that such a mission will be able to detect life in such an ocean even if the ocean exists and such life exists. That 1.7 billion dollars could have funded 100 or 1000 scientific research projects that would all have been more worthy of funding than the JUICE mission.
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