Exposing PseudoAstronomy

May 28, 2009

Jupiter: Further Confounding Those Darn Evolutionists


Today I had a happy occurrence – Phil Plait mentioned me in his “Bad Astronomy” blog in the context of my previous post on this subject. As a consequence, my blog received over a 5-fold increase in hits. Thanks, Phil, and thanks to all of you who came here from the BA blog.

The purpose of this particular post is a follow-up on that first one. In the first one, I wrote that the video sample on the CreationAstronomy.com blog is approximately 13 minutes long. However, I was only able to view about 4 minutes of it for free from the website. Well, one of the readers of my post sent me a link to download the full section of the video.

So, without further ado, let’s examine the claims in the next 9 minutes of the video.

The Rest of Psarris’ Claims

1. “The more we study Jupiter, the more evolutionists have realized it doesn’t fit into their models.” He then shows another quote from Richard Kerr (the same author he quoted from out of context in my first post on the subject) stating, “… no one has a satisfying explanation of how they were made.” Psarris then states that, no, that’s not true, “the Bible has a very satisfying explanation of how they were made.” (3 min 50 sec)

2. “Jupiter has over 60 moons; they pose problems for evolution, too.”

2.a. “Ganymede has one of the most bizarre surfaces in the entire solar system. … Evolutionary models predicted that Ganymede couldn’t have a magnetic field. But when our space probes arrived and started taking measurements, we found that it does have a magnetic field.” (4 min 30 sec)

2.b. “Then there’s Callisto. This moon is the most heavily cratered object in the solar system. Evolutionists believe that it has one of the oldest surfaces of any object, about 4 billion years old. It was a real surprise, then, when our space probes took some close-up pictures.” It was expected that there would be many small craters, but there was a lack of them. Also, “some of the pictures show what appears to be fresh ice on Callisto’s surface, … [but] evolutionary models say Callisto is old, cold, and dead.” (5 min 30 sec)

2.c. “Next, there is Europa. … Europa is the smoothest [object in the solar system]. … [The ice on Europa] is several miles thick, but some scientists think there might be liquid water beneath it. And where there’s water, there has to be life, right?” Apparently in a previous video section he addressed “how ridiculous that idea is,” but Psarris goes on to say, “you still hear it in the news a lot: Somebody finds a new crack on Europa, and thinks, ‘Ooo! Look! Water might ooze into the crack, and there could be life evolving in the water!’ Then some reporter runs a story about it saying we’re on the verge of finding life elsewhere in the solar system even though all we found was a crack in a moon.” (6 min 30 sec)

2.d. This claim deals with craters on Europa, about which he makes a claim straight from the Institute for Creation Research (I know this because I already debunked this claim before): “Because Europa has only a few craters, we’ve been able to study them closely. One recent study has shown the evolutionary model for cratering is all wrong.” He goes on to explain that it’s apparently wrong because a single crater forming can create up to a million or so smaller, secondary craters (formed by debris from the primary crater event). Because of this, he makes the claim that you need fewer impactors to make all the craters we see, which then implies a younger age than “all these billions of years.” Psarris then extrapolates this to Venus and the moon. (I’m not going into significant detail here since I’ve addressed it extensively before, and I’ll talk about it in my next section where I address these claims.) (7 min 10 sec)

2.e. For the last of Jupiter’s large moons, Io, Psarris makes light of the massive volcanism on Io’s surface. Psarris’ main claim is simply that Jupiter’s tidal heating of Io is not enough to account for all the heat, so some of it must be left-over from its formation which means it formed recently. (9 min 15 sec)

2.f. The second of the Io claims is that, given the amount of lava that is erupting, Io must have completely recycled itself 30 times in the ~4.5-billion year history of the solar system. (10 min 30 sec)

2.g. We get a third claim out of Io: Apparently, astronomers were “flabbergasted” to learn that the temperatures of the lava on Io reaches 3000°, when it only reaches 2000° on Earth. Also, the lava is dense when it should be formed of low-density material by this point due to simple differentiation (heavy stuff sinks). (11 min 20 sec)

The rest of the video (post-12 min 15 sec) is a review of all the points that Psarris makes. But, there are some typical statements at the end:

  • “Evolutionary models fail utterly to explain Jupiter.”
  • “Building Jupiter has long been a problem for theorists.” (Wetherill, 1995)
  • “I don’t think the existence of Jupiter would be predicted if it weren’t observed.” (Wetherill, 2001)
  • “Why do they still cling to a broken model? Because when you reject the Truth, you have to accept a lie.”
  • “Pity the poor evolutionist, who is so committed to a bankrupt theory that he can’t see the hand of his creator in this majestic planet.”

Addressing the Remaining Claims

1. No Models Explain How Jupiter Formed

This is simply not true, and at its nicest level is taking statements out of context and sorely downplaying the status of solar system formation modeling. I address this quite a bit in my first post in this 2-part series.

The other aspect of this claim that deserves to be addressed is the very common “god of the gaps” logical fallacy: “We don’t know how this happened, therefore God did it.” Among the skeptical community, this often is compressed into the single word, “goddidit,” because we hear it so often from Creationists. The basic fallacy here is that you confuse something that we don’t currently know with something that we can’t possibly know, and therefore it is only explainable through the miracles that a divine creator can make.

2.a. Ganymede

Ganymede’s magnetic field is interesting. But, as I stated in my first post about this CreationAstronomy.com site, that’s what makes astronomers happy! We like it when we find something that we can’t immediately explain. If nothing else, that means Job Security! But on a more explanatory level, the theory for the formation of a magnetic field on a planetary scale is that it requires a molten interior, but Ganymede shouldn’t have one by this point in its life because it should have cooled. On that point, Psarris is correct. But, what does this mean, then, for an explanation?

It means that we need to explain how Ganymede’s core could have either remained warm until at least 1 billion years ago or was heated up until about 1 billion years ago (since a remnant field can still exist for ~1 billion years even without something actively driving it). What modelers have come up with is that the main jovian satellites were not always in their current orbits, but that they slowly migrated into them. This migration passed through resonances until it got to its current resonance of 1:2:4 (Io, Europa, Ganymede … Callisto isn’t really in a resonance (yet)). Getting into this resonance caused enough tidal heating to create a dynamo in Ganymede’s core. In other words, there’s a perfectly reasonable dynamical model that explains this without resorting to goddidit.

2.b. Callisto’s Lack of Small Craters

This is another (almost) true observation about Callisto: It does lack as many small craters as were predicted from simple cratering models. Note here that “small” is ~1 km sized craters and smaller. Before I get into possible explanations, though, I have to pose the likely rhetorical question: How does a lack of small craters prove the solar system is young? I honestly don’t see how it has any relevance to it, other than under the quite childish false dichotomy notion that, “if I can show you’re wrong, then I must be right!”

What this implies, however, are a few different things. One idea is that the main impactor population of Callisto – possibly comets – simply lacks a small size population (impactors a few 10s to 100s of meters). Personally, I don’t find that explanation incredibly convincing from my own research in craters, however. Another possible explanation (Bierhaus et al. (2000) “Small Crater Populations on Callisto”) is that it is simply a resolution issue, and that when viewed under higher resolution, previously indiscernible small craters become evident.

There are also other possible explanations here, but my main point is one that I’ve been stressing when dealing with this CreationAstronomy.com website: A lack of conforming to known, simpler models is something that astronomers – and scientists in general – like, because it means that they then get to go and figure out a new model to explain the new results.

2.c. Europa -> Liquid Water -> Life?

This claim is one that I’ve addressed before, namely in my post, NASA’s “Follow the Water,” Ice Detected by Phoenix on Mars, and Noah’s Flood. It’s one of my older posts so not as well organized, but the basic idea is that all life that we know of needs liquid water to live. Therefore, the first step in attempting to find life is to find places where liquid water is. It’s that simple.

2.d. Europa and Secondary Cratering

This is another claim that I have addressed, in-depth, before. The post is, Dating Planetary Surfaces with Craters – Why There Is No “Crisis in Crater Count Dating”. Psarris’ claim really is identical to this ICR article. The basic response boils down to: Astronomers know of the issue. And we take it into account. It’s another of the classic creationist tactics where they will give you a problem with “evolutionary” science and then say it invalidates everything about science, but they don’t tell you that we already know about the issue and take it into account.

2.e. Io Is Too Hot

Says who? I have not heard nor seen this claim before, and I took a graduate class from the guy who literally wrote the book on Jupiter’s moons. If Psarris would like to show his calculations, I will gladly look over them and get back to this claim.

2.f. Io Is Erupting Too Much

While the basic idea behind this claim is not new, I have never seen it before raised as an issue. Planetary crust is recycled. Stuff coming out of volcanoes on Earth now used to be buried miles beneath the surface which used to be on the surface. I’m sorry, but I honestly don’t see the issue here with this claim.

2.g. Io’s Lava is Too Hot and Too Dense

First, I just love it when articles say that scientists are “flabbergasted,” “surprised,” “shocked,” “astounded,” “puzzled,” “clueless,” “can’t understand,” “unbelieving,” “amazed,” “bewildered,” “baffled,” and other such phrases. (Okay, more honestly, I really don’t like it.) Seriously, we’re apparently the people who are supposed to know everything and so it’s like a “gotcha” game when there’s a discovery that “surprises” us. Need I repeat it? THAT’S THE POINT OF SCIENCE — TO FIND OUT NEW THINGS!

Alright, deep breath … now, what about the temperatures of Io’s volcanoes. Again, I do not know of why this is particularly an issue. If Psarris would like to show his math – or show someone else’s as to why magma cannot be heated to 3000° on Io, I will take a look at it. But this is another case where I do not particularly want to do his work for him to then add more work to my own plate.

Final Thoughts

I’ll start off by saying that I threw this post together rather quickly (if “quickly” can mean an hour of writing and looking things up and watching the video segment), so I apologize if I seem a little flippant at the end, brushing off his claims.

However, my point really is the same: If he is going to make the claim, he needs to back it up. You can’t just state something and leave it at that and expect people to bend over backwards to flesh out your own claim and then go to the trouble of pointing out why it’s wrong (if it actually is). And at least with the few physics things that Psarris addresses (basic thermodynamics), he needs to show the math. Otherwise, it holds as much weight as me saying that my oven can’t possibly heat up past 500° by itself therefore it contains heat left over from its formation which means it’s young.

Otherwise, I hope that at the very least this post will lead you to question the validity of Psarris’ claims. And if you’re already a firm critic of young-Earth creationism, then I hope that I have armed you with more information to stop the spread of bad pseudo astronomy.

May 23, 2009

Jupiter: Confounding Evolutionary Models of the Solar System


Making the rounds on the blogs and skeptical websites – including PZ Myers’ Pharyngula blog – is an up-and-coming young-Earth creationist, Spike Psarris and his CreationAstronomy.com website. Now, when I was made aware of this site, I tried to go to it but kept getting 505 errors meaning that they had exceeded the bandwidth they paid for.

I’m guessing this was due to PZ’s blog post about it. Well, a few hours later, it was back up and I got to see what the hooplah is about. It’s a guy selling a YEC DVD. He has a free preview on his site – at least at the time of writing this blog – that shows the intro to the DVD and the “chapter” on Jupiter.

The title of this blog post is what he claims within the first minute of the Jupiter video segment. The rest of this post will be correcting the errors, half-truths, and misstatements throughout the rest of the 13-minute video.

Update: I have posted a follow-up analysis of the Jupiter segment claims that are not addressed in this post here: “Jupiter: Further Confounding Those Darn Evolutionists.”

Psarris’ Claims

There are many claims made in this segment. The main points are the following:

1. “Evolution says Jupiter can’t be spinning as fast as it is … [because] evolutionary model make certain predictions about how fast a planet should spin.” He then quotes a “recent” article to back this up, where “recent” is 1992. He then makes the argument that evolutionary models cannot supply the energy to spin up Jupiter such that its day is only 10 Earth hours long. (1 min)

2. “Evolutionary models predicted that Jupiter would lack certain elements, Ar, Kr, Xe, N, and others. But it turns out that Jupiter has lots of these elements. … [An overview of the article of the results said] ‘Jupiter is the largest of all the planets, but results in Nature now reveal the embarrassing fact that we know next to nothing about how – or where – it formed.’” (2 min)

3. “The evolutionary model requires Jupiter to have a large core inside of it [at least 10 times the mass of Earth]. This would have been necessary for Jupiter to form from the solar nebula billions of years ago. Unfortunately for evolution, a recent space probe measured the mass of Jupiter’s core. … We now know that, at most, the core can only be 3 times the mass of Earth. … Jupiter does not match evolution’s predictions.” (2 min 30 sec)

4. The next claim is that models require 10-100 million years for a planet like Jupiter to form, but that the solar nebula would have dissipated around the sun within 5 million years. “So, according to evolution, Jupiter shouldn’t exist at all.” (3 min 15 sec)

This is where the video stops for me. Even though my player lists the video as being 13 min 28 seconds long, it keeps stopping after 3 min 54 seconds. But, that’s really enough to get a flavor of the video, so let’s get to what’s really going on.

The First Big Clue

Okay, even if you’re a young-Earth creationist, please please PLEASE stop talking about astronomy in terms of “evolution,” “evolutionists,” and “darwinism.” The Theory of Evolution has ABSOLUTELY NOTHING to do with astronomy (unless you are talking about really far down the line things). Natural selection says nothing about how planets form. Punctuated equilibrium has nothing to do with the gases in Jupiter’s atmosphere.

Now that I’ve gotten that out … the first big clue as to an alternative agenda (as if that weren’t obvious from the get-go) is relating evolution to astronomy. As if somehow showing that Jupiter’s rotation rate cannot be explained by an outdated model has something to do with the validity of common descent of species. And this is quite telling in this clip because in practically every single sentence, Psarris claims that this has to do with evolution, evolutionary models, or evolutionists.

With that said, I will not address the non sequitur “evolution” references in each and every claim when I address them in the next section.

Addressing the Four Main Claims

1. Jupiter’s Rotation Rate

First off, I should note that we have known what Jupiter’s rotation rate was as far back as 1835 (since that’s the first paper that I can find on the subject) but I would guess that Galileo was able to estimate its rotation period, as well. For those interested, here is the article from 1835.

With that out of the way – we know how fast it’s spinning on its axis – how does it spin so quickly? The preliminary question would be, why does it spin in the first place? This webpage has a pretty good simplified explanation for why objects in the solar system spin, and why they mostly spin in the same counter-clockwise direction (when viewed from the North Pole). The basic one-liner is that the protoplanetary disk was orbiting the protosun in the same direction, and due to the differential rotation within the disk, a net spin was imparted onto any condensing objects.

And now we get to the part where the objects spin quickly. This is the classic ice skater analogy: If your spinning on the ice and you have your arms extended, you will spin slowly. If you bring your arms closer to your body, you will spin faster. That is because of the conservation of angular momentum. Now let’s say you put 20-lb lead weights in your hands. If you now bring your arms close to your body, you will spin even faster than before. In other words, the more mass you bring close to the center, the faster you will spin.

Jupiter has a lot of mass – the most mass of any object other than the sun in the solar system. It also has the fastest rotation rate. Saturn, the second-most massive planet, has the second-fastest rotation rate. Neptune, which has the third-largest mass, has the third-fastest rotation rate. See a pattern?

Now, I’m not sure what “evolutionary model” he’s talking about that predicts a slower rate. He doesn’t cite his source. Regardless, he has not presented any case that anyone should take seriously as to why Jupiter “can’t” spin quickly under an “evolutionary model,” so at best this is an unsupported claim where the burden of proof is solely upon him to at least present reasoning rather than a simple claim.

Update since original post: I have now obtained a copy of the paper that Psarris quotes from (Kerr, (1992), “Theoreticians are putting a new spin on the planets,” Science, 258: 5082, p. 548.). This is a very obvious example of a fairly common YEC tactic, quote-mining. This is where they search for a line or two in pretty much any scientific paper/book/press release and use it completely out of context.

In this case, the quote is, “The simulated bombardment leaves a growing planet spinning once a week at most, not once a day.” The main problem is that, just as I point out in the rest of my blog, this isn’t a “naked” announcement — the two teams that this paper cites have modified current models in order to explain how the planets spin faster than once a week. In fact, that quote comes from the fourth paragraph. The second paragraph states: “Neither group claims to know exactly what actually set the planets spinning so furiously. But both groups–Stony Brook’s Jack J. Lissauer and David Kary and Toronto’s Luke Dones and Scott Tremaine–are ready with alternative scenarios. Lissauer and Kary favor a modified version of the small-collisions scenario, but Tremaine and Dones lean toward a more catastrophic mechanism, in which planets acquired their spins from a few giant impacts, or even one, late in their evolution.”

I can’t go on to quote the paper verbatim because that is not the purpose of this blog post and it is not completely legal (and the paper requires a subscription to the journal in order to read it). But the upshot is that this paper simply describes, in short, two small modifications to the main planetary formation models that can better account for a preferred direction once you consider even more of the real, physical dynamics that occur in a protoplanetary disk.

2. Elemental Composition

This second claim is at best misleading, at worst just an outright lie. The main composition of Jupiter is H2 (molecular hydrogen) at 89.8% (±2.0%). The secondary element is He at 10.2% (±2.0%). Notice that those two add up to 100%. Now, there is a very little bit of other stuff, but it is what we call “trace,” meaning that there is very very little of it there.

The main trace constituents are methane (0.3±0.1%), ammonia (0.026±0.004%), hydrogen dueteride (.0028±0.001%), ethane (0.00058±0.00015%), and water (0.0004% (varies with pressure)). This is data from NASA’s Jupiter Factsheet.

Looking at a recent paper, the amount of argon in Jupiter is about 2.5x the sun’s or ~0.0009% of the total composition. Krypton is 2.7x the sun’s, or ~0.0004% the total composition. Xenon is 2.6x the sun’s, or ~0.0004% the total composition. And nitrogen is 3x that of the sun’s abundance, or ~0.0003%. It’s noted in the paper that the nitrogen amount is likely off, that the probe landed in a “hotspot.”

Now why are these tiny tiny numbers cause for mention? Well, they do show a relatively significant enhancement over the solar abundance, and Jupiter is supposed to be reasonably like the sun in its composition. But not totally. What I have noticed that creationists commonly fail to realize is that scientists want to make observations that disagree with their theories. But rather than throwing away their theories, they modify them in order to improve the theories so they can explain all of the evidence. That is what has happened since the determinations of the jovian atmospheric composition: It has placed constraints on models of Jupiter’s formation. Rather than make assumptions, we now have legitimate constraints upon parameters, like where in the solar nebula Jupiter may have formed, or where the smaller pieces that combined to form Jupiter may have formed themselves.

That is what real science is: Making a model from current observations and then making predictions from that model. If future observations do not match those predictions, then the model must be altered or replaced in order to be able to account for the new observations. We can still build Jupiters in planetary formation models (as opposed to evolution models). We just now have more constraints upon how, where, and from what they form.

3. The Core of Jupiter

This claim is fairly silly at this point in time. Before the Galileo probe reached Jupiter in the 1990s, estimates of the size of the core of Jupiter were around 5-15 Earth masses, though the actual value varied considerably based upon what model you used and what you assumed (think back to section 2 above on how science is done).

Once Galileo reached Jupiter, it was able to take various measurements and it being in orbit allowed various tracking stations on Earth to record its position — allowing us to create a model of Jupiter’s gravity field. This, along with Jupiter’s moments of inertia, are needed to really constrain models of how big Jupiter’s rocky, solid core may be — or if it even has one.

The current state of the science, however, is inconclusive. The measurements from a decade ago were not good enough to conclusively state whether or not Jupiter has a core, and how large it may be. The data generally indicate that the core can be no larger than ~12 Earth masses — a far cry from whatever source Psarris used that said the core can be a maximum of only 3 Earth masses. But, the results from Galileo provide few limits towards the size of the core, and so it is still not well-constrained. One example reference is: Guillot, Gautier, & Hubbard, (1997), “New constraints on the composition of Jupiter from Galileo measurements and interior models” Icarus.

Another recent paper (where I use “recent” as meaning 2008) models what Jupiter’s core will be from first principles of physics and comes up with 14-18 ±6 Earth masses, within the range of what Galileo results show.

4. Formation Timescale

The next claim is that the solar nebula would disappear within 5 million years, but Jupiter takes 10-100 million to form. Obviously a problem!

But that’s what happens when you take the extreme numbers on the one hand with the opposite extreme numbers on the other, along with outdated models.

Let’s look at the 2004 publication, “Formation of the giant planets,” from 2004. The author clearly states that the protoplanetary disk will dissipate within 1-10 million years. So, yes, the “5 million years” number Psarris quoted is reasonably accurate and jives with the latest science.

However, this isn’t a “gotcha” moment for the YECs. It’s not as though they caught us astronomers with our proverbial pants down, that we didn’t realize there’s a contradiction here. We do. And yet again, this simply serves to place further constraints on how planets can form. And new models have come out of it.

The main model of forming planets is referred to as the “core instability model,” and it takes 6-8 million years to form a nice-sized gas giant. A possible problem. Then there’s the “disk instability model,” which is at-present poorly modeled but promises to form planets somewhat faster. This is still a very active area of research, and the state-of-the-art can change over the course of a grad student’s tenure. (Case-in-point: There was a grad student in my program who was 4 years ahead of me who, when I took the “Planetary Formation” class my third semester, sat in on the class. I asked him why, and he said that it’s changed so much in the 4 years since he took the class that he wanted to see what people were discussing now.)

One example is this model which proposes a diffusive redistribution of water as one of the primary mechanisms for forming Jupiter, and they can form Jupiter’s core within 100,000-1,000,000 years. Or there’s this paper, which forms the gas giants by concurrently accreting both solids and gas (generally thought to accrete separately). It can form Jupiter and Saturn in 1-10 million years.

Of particular interest in planet formation, to be honest, is how Uranus and Neptune form. All models require significantly longer timescales for them because they are farther from the sun. The fastest I’ve seen still requires ~2x as much time to form. them as Jupiter and Saturn, but they have to form while there’s still enough of the solar nebula left.

The very first line of a 2002 paper by Thommes, Duncan, and Levison states, “The outer giant planets, Uranus and Neptune, pose a challenge to theories of planet formation.” Even though this was written over 8 years ago, it still holds true today. They do pose challenges. But astronomers welcome those challenges as opportunities to learn more about the universe around us rather than throw up our hands and turn to a young-Earth creationist model, which is ultimately what Psarris wants you to do.

Final Thoughts

In general, Psarris is not presenting new arguments. I’ve heard of the last two before, though not the first two. And I can almost guarantee that he uses some of the classic arguments that I’ve addressed before in other sections of his DVD.

What’s the bottom-line? He points out apparent observational evidence that seems to conflict with the “evolutionary” picture of Jupiter. The problem with that is astronomers know about these problems – if they are problems at all – and we actually use them rather than ignore them in order to refine models of how Jupiter formed and has changed through time. All because it has 3x more nitrogen than the sun does not mean that astronomers will suddenly throw up their hands in despair and change their views to reflect that of young-Earth creationism.

But, for $19, that’s what Psarris is going to try to convince you of.

Update: I have posted a follow-up analysis of the Jupiter segment claims that are not addressed in this post here: “Jupiter: Further Confounding Those Darn Evolutionists.”

May 8, 2009

Is Saturn a Young System? Apparently, According to the Institute for Creation Research


In the last few days, I’ve seen a few blog posts about Saturn being a young system on the usual creationist sites or those responding to the creationist sites, and being a bit behind in my blog, I thought I’d check out the usual suspects. Predictably, I found the article posted yesterday, May 7, 2009, on the Institute for Creation Research by my own favorite, Brian Thomas (who I picked apart in this blog post.

The article in question now is entitled, “Planetary Quandaries Solved: Saturn Is Young.” Okay, I admit I needed to take a deep breath with this one before reading it. After all, you’d think that if scientists had really discovered that Saturn had been created/formed recently, it would be all over the news, right? So right off the bat, the title is misleading, but understandable for a creationist website.

Then I picked through some of the references. Why? Because I actually do research on Saturn’s rings. I will be submitting revisions to a 50-page manuscript to the journal Icarus in the next 3 days that should be published in a special edition of the journal at some point this summer, and the conclusions from my simulations are that the ring system is at least 2 times as massive as before, likely more, and the implications are that the system can then easily be a corresponding amount older (e.g., at least 2 times older).

And, lo!, one of the references in the article directly cites my work — a ScienceNews article from September 2008. (Check out paragraph 4 of the article.) So now, it’s personal — Brian Thomas is using MY research (in part) to advance his creationist agenda, and I will not be silent about it. Hence this blog post. :)

What Is the Evidence the Saturnian System Is Old?

Let’s ignore all of the outside evidence that it’s old. Let’s ignore solar system formation models. Let’s ignore standard conventional wisdom. Let’s ignore the scientific problems about biblical creation. What is the evidence that the system is old, or at least not young.

Well, being a crater counter when I’m not running simulations of Saturn’s rings, I point to craters. Craters are used throughout the solar system as the only cross-planetary method of relative dating methods. In other words, how many craters a solid object has is the only thing that we can measure, at present, that gives us the relative ages of two solid surfaces.

Crater ages have been calibrated via Apollo lunar sample returns, and so – at least for our moon – we know that a certain number of craters per unit area corresponds with one age, and a different number corresponds with a different age — and we know what those ages are to reasonable accuracy for the moon.

Much work has been done and is being done to try to extrapolate what we know from our moon to other solid bodies, including Mercury, Venus, Mars, and the giant planets’ satellites. While the work isn’t perfect and uncertainties remain, the state of the research is that we can tell the difference between an object that is 6000 years old or 4 billion years old.

The surface of Titan? The last number I saw is that there are around 150 impact structures that have been observed, so the present-day surface age of Titan is reasonably young. Yes, I admit that — I’m not hiding it.

What about the surface of the other moons, such as, say, Iapetus? Well, take a look at the image to the right. There are A LOT of craters there, and the surface age of Iapetus is likely on the order of a few billion years (I say “likely” because I haven’t actually done the crater counts there). Now, unless you’re going to engage in some very special pleading, this is pretty good independent evidence that at least some parts of the Saturnian system is old.

Enter the Argument for Youth: Saturn’s Rings

I grew up reading that Saturn’s rings were young – probably formed only 100 million years ago after the breakup of a medium-sized moon, about the size of Saturn’s moon Mimas (shown on the right). That was based on a few things, including estimates of its mass from Voyager data as well as spectroscopic observations showing that the rings are fairly “fresh,” showing relatively little contamination by, basically, space dust.

This was still the predominant idea in 2002, when Jeff Cuzzi made his quite that Brian Thomas uses in the second paragraph of this article:

A history of mystery surrounds the youthful features of Saturn’s rings. Jeff Cuzzi, a planetary scientist at the NASA Ames Research Center, said in 2002, “After all this time we’re still not sure about the origin of Saturn’s rings….There’s a growing awareness that Saturn’s rings can’t be so old.” Cuzzi said, “There are two reasons to believe the rings are young: First, they are bright and shiny like something new. It’s no joke.” Indeed, after millions of years, the icy rings should have collected so much space dust that they should be charcoal-colored by now. Second, after only a few million years, the little moons embedded among the rings should have “flung away. This is a young dynamical system.”

And, this was still an issue in 2006, when I was just starting my simulations. The third paragraph of this article cites Josh Colwell in a presentation he gave. He was listing some of the current problems in a few-billion-year-old rings system, but the problems were still based on old data estimates for both the mass of the ring system and the viscosity of the particles (viscosity can be thought of as how well particles can transfer energy from one to another or how well they flow — water is not very viscous but molasses is).

Enter the simulations. I use Mark Lewis’ code for these simulations, and I make a point of that because Mark is quoted in the fourth paragraph of the ICR article:

Mark Lewis of Trinity University in San Antonio cautioned that it is still not known how they really clump. “It isn’t as straightforward as saying that high-density particles would lead to more clumping.”

This is true. There are many different parameters that go into these simulations to model the physics involved. Even though I explored a huge range of parameter space in my simulations, performing over 150 different N-body simulations that took over 27,000 CPU hours to run, I still did not explore the whole range of space, and a few of those parameters do affect how ring particles clump together.

Clumping is important because it directly affects how we estimate the mass of the rings. If the rings do not clump at all, then for every particle it will block an equal amount of light. Kinda like if you spread a lot of sand on a sheet of paper and you spread that sand evenly around, you will only see a little of the paper through the sand. But, if you use the same amount of sand and start to make little sand piles, you will see more and more of the paper.

That’s how we estimate the mass of the rings – by how much paper (how much light) can be seen through the rings. And, if the ring particles are clumped together, then you need many more ring particles to get the same amount of light blocked. What my simulations show is that clumping plays a much larger role than previously thought, and so we need more material in the rings to match the observed light-blockage.

Why do more massive rings mean that the ring system is older – or can be older? Because more massive rings means the viscosity is higher and so they spread out more slowly (one of the arguments they were young is that they would spread out too quickly). Also, it means they can be older because the same amount of pollution will get spread out over a larger area, and hence they won’t be as “dirty.” So, arguments that they are young because they don’t show a large amount of pollution can be answered that the pollution is just better hidden than we thought because there is more material within the rings to get polluted.

What was the connection to me here? Well, they’re my simulations. And that fourth paragraph has a quote from an article that talked about my results. Hence why I take this a little personally.

Moving On to Enceladus

In paragraph 5 of his article, Brian Thomas says that Saturn’s moon Enceladus “shows no hint of being 4.5 billion years old, but instead appears remarkably young.” I’m not going to harp on Brian’s grammar mistake here because I’m sure I have made my fair share of mistakes in this article grammar-wise, but I will say that it’s a poor journalist who doesn’t know what a sentence fragment is.

Anyway … this statement is simply wrong. It is true that the geysers that were discovered coming from Enceladus’ south polar region were a surprise, and they have made many people in the planetary community excited to find out why they are there. (Note – yes, new discoveries that challenge old models make scientists happy, not upset, as creationists would have you believe.) And a lot of Enceladus’ surface does appear to be young. However, a fair portion of the surface also appears to be very old, as shown in the picture on the right. Yes — I’m talking about all those craters.

Final Thoughts

That’s really the point of this article. So, no, the planetary quandary has not been “solved” to say that Saturn is young. Rather, the ring system can still easily be old based on the latest (and if I do say so myself, the greatest) simulations, and even though some features of Enceladus appear young and active, there are other parts of the moon that tell the tale of being ancient.

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