Blue Collar Scientist

One of the common arguments trotted out by global warming denialists is that:

1. The sun emits cosmic rays
2. The number or energy of these cosmic rays varies with solar activity
3. The Earth’s magnetic field, and the solar wind, tend to divert cosmic rays away from the Earth
4. But when the solar wind is weak, more cosmic rays hit the Earth
5. Which creates more charged particles in the atmosphere
6. Which somehow causes more cloud formation
7. Which cools the climate
8. But when the solar wind is strong again, then the Earth warms up

This is based on the research hypothesis of Henrik Svensmark of the Danish National Space Center, so this is not a lunatic idea. What is lunatic is the way that the denialists latched on to the idea before it was tested, and presented it as fact, used it to denigrate other scientists and suggest they are fools, and so on. In real science, you come to these conclusions after the experiments have been done, not before.

But now some experiments have been done, and the hypothesis has not held up very well in testing. Several experiments and analyses have called the hypothesis into serious question over the last couple years.

Now, there’s yet another scientific study which shows that things just don’t work like that. Or at least if they do, the differences between strong and weak solar wind periods are way to small to have a noticeable effect on clouds.

The abstract is not particularly difficult, but I want to make some remarks on it anyway, so here it is with my comments interspersed:

A decrease in the globally averaged low level cloud cover, deduced from the ISCCP infrared data, as the cosmic ray intensity decreased during the solar cycle 22 was observed by two groups.

So cloud cover was observed to decrease, and cosmic ray intensity decreased; this much is known.

The groups went on to hypothesize that the decrease in ionization due to cosmic rays causes the decrease in cloud cover, thereby explaining a large part of the currently observed global warming.

This hypothesis takes advantage of the fact that many times, correlation really does mean causation. Not always - but sometimes.

We have examined this hypothesis to look for evidence to corroborate it.

Yay science! That’s how it works. Someone comes up with an idea about how things might happen, and you get a bunch of interested scientists doing experiments to see if that idea is right.

None has been found and so our conclusions are to doubt it. From the absence of corroborative evidence, we estimate that less than 23%, at the 95% confidence level, of the 11 year cycle change in the globally averaged cloud cover observed in solar cycle 22 is due to the change in the rate of ionization from the solar modulation of cosmic rays.

How does this hurt the denialists’ cause? Well, it doesn’t, because they’re denialists. Mere facts won’t get in the way of their political agenda.

But if they did respect evidence, this analysis puts an upper limit on just how strong the cosmic ray/cloud cover correlation could possibly be. And that upper limit isn’t anywhere near what is required to account for the observed climate change.

The researchers are still arguing about things, with Svensmark basically calling Terry Sloan, the PI of this study, an idiot:

“Terry Sloan has simply failed to understand how cosmic rays work on clouds,” he told BBC News.

To me, saying that a highly-qualified researcher in the same field simply doesn’t understand is a strong sign that the person saying it is on weak ground, although we don’t really know what Svensmark said that didn’t get into the BBC story. But Slaon describes the very elegant experiment that he and his co-investigators did, and it is compelling:

Professor Sloan’s team investigated the link [between cosmic rays and cloud cover] by looking for periods in time and for places on the Earth which had documented weak or strong cosmic ray arrivals, and seeing if that affected the cloudiness observed in those locations or at those times.

“For example; sometimes the Sun ‘burps’ - it throws out a huge burst of charged particles,” he explained to BBC News.

“So we looked to see whether cloud cover increased after one of these bursts of rays from the Sun; we saw nothing.”

Dang, that is good science communication. That boils a really complex and difficult series of physical processes down to something that anybody will have enough attention span to listen to. Kudos to Terry Sloan.

The experiment makes a lot of sense to me. The Earth is not a point collector of cosmic rays; different locations on the Earth gather them unequally. Cosmic rays are highly localized. We see them all the time in CCD camera images of the night sky in my asteroid research¹, and occasionally some images have a striking abundance of cosmic ray strikes that hasn’t occurred at a nearby observatory. Dedicated cosmic ray detectors show that some parts of Earth can experience a veritable storm of cosmic rays, while other parts get the usual amount.

The fact that Sloan took advantage of this well-known localization of cosmic ray strikes, and found no evidence that cosmic rays were even correlated with clouds - let alone causative - is very strong evidence against the denialists’ position.

As I mentioned above, this is probably not going to penetrate the denialists’ understanding, and will make no difference to them in terms of aggressively pursuing their scorched-earth political agenda. They’ve irrevocably burned into their mind the false notion that believing in global warming means you are an enviro-communist. They don’t understand the research, and they don’t want to. But there’s something else they don’t understand: that people can accept the evidence for global warming, and yet still want to drive gasoline-powered automobiles that pollute less. And that pursuing a vigorous domestic and alternative energy policy would result in a strong economic stimulus.

Anyway - scientific evidence is cool², and we’ve got an interesting case here.

1. They are extremely annoying, not only because of the artifact it leaves in the image, but also because you then envision these things flying through your body, which is many times larger than the CCD detector…. [↩]
2. No pun intended. [↩]

Is there something about the University of California PR system that causes it to occasionally kick out weird press releases? It happened before with a really bad one from UC Davis, and now there’s a merely odd one at UC Santa Barbara.

An international team of astronomers has found 10 new “extra solar” planets….

Cue the sound of a record player being bumped hard and the music ending in an abrupt scratch. Really, we’ve called these things simply extrasolar planets (or exoplanets) for about fifteen years. No quotes necessary. And all one word, please, because extra solar would mean we’ve got some spare planets hanging around in our own solar system (can you imagine passing stars asking, ‘hey, buddy, can you spare a planet?’), and we really do mean extrasolar, as in outside the solar neighborhood. Just like extra ordinary means something that is as utterly ordinary as possible, while extraordinary means definitely outside the ordinary. Here, this may clear it up:

Extra ordinary car: You are going to the trouble of special-ordering the model without power windows even though the cost savings is less than fifty bucks.

Extraordinary car: Zero to sixty in three seconds, 500 miles to the gallon.

This technique of locating the planets gives more information about the formation and evolution of the planets than the gravitational technique. Astronomers look for “transits,” moments when the planets pass in front of the star, like an eclipse, as viewed from the Earth.

Ok, that’s pretty good. It is “like an eclipse,” and that’s not a bad comparison to make, especially since the accompanying pictures show that it isn’t really an eclipse.

Don’t need the quotes around transit, though. The word is in the dictionary, it isn’t something novel or made-up. Everyone has heard of mass transit and rapid transit, we just need to be sure the special meaning here of “passing in front of” is conveyed. And that isn’t done with the quotation marks.

With the gravitational technique….

Ok, really this is talking about the radial velocity technique, more commonly called the doppler technique in the press. We’re not detecting extrasolar planets gravitationally. We’re not detecting anything gravitationally. Yet.

With the gravitational technique, scientists have discovered around 270 extra solar planets since the early 1990s. They measured the gravitational pull on the star that is exerted by the orbiting planet.

No, they can calculate that, but they can’t measure it. They are measuring doppler shift.

As the planet moves, it pulls on the star, tugging it back and forth.

Yes!

However, making these discoveries depends on looking at each star over a period of weeks or months, so the pace of discovery is slow.

Actually, the pace of discovery would be quite high if you were looking for multi-Jupiter mass planets orbiting close to the star, even if you were using the radial velocity method. If the planetary orbit is three days, you just need three days to get a full orbit’s radial velocity data. This is why the discovery of so many “hot Jupiters” were made when these programs began. The fact that they hadn’t been operating long meant that the only kind of planet they could possibly detect were ones with really short periods.

The SuperWASP technique involves two sets of cameras to watch for events known as transits, where a planet passes directly in front of a star and blocks out some of the star’s light.

Credit where it is due: This description is perfect.

It is, however, the second time the concept is explained in the release. Move it up to where the first attempt was made, and you’d improve things.

A total of 46 planets have been found to transit their stars.

Ewww. This usage might not be strictly wrong, but it sure seems wrenching to me. I think this is because of two attributes of transits: All planets transit their stars from some perspective in the universe. And a transit isn’t a sign of anything interesting; it is just an accident, a chance alignment. Think of it this way: a planet orbits for a reason provided by physics - gravity. But a planet transits because you just happen to be lined up with it.

I’d have said something like: “A total of 46 planets have been found using the transit method.”

The planets discovered by SuperWASP have masses between a middle weight of half the size of Jupiter to more than eight times the size of Jupiter, the largest planet in our solar system.

Er - what? Of the planets discovered by SuperWASP, is the middle weighted one, i.e., the median, half the mass of Jupiter? I think not - that would be a really low median size for these detections. It must mean that a planet half the mass of Jupiter, which is the smallest SuperWASP has discovered, is a middleweight (note the lack of a space, as a space changes the meaning of a compound word), as in the weight class from boxing.

Unfortunately, that’s completely wrong. I think. Let’s say that if there is a fact here, it’s wrong. And if there isn’t, then it’s strange.

Jupiter has a mass of 318 Earths. The next most massive planet in the solar system is Saturn, which has a mass of 95 Earths.

Bear with me here: Half a Jupiter is still 159 Earths, way bigger than Saturn, which is the second biggest of eight planets in the solar system - a very big planet.

The middleweight planet, - if you line up eight planets in order of mass and you pick the one in the middle - is harder to determine, since there are an even number of planets. So you have to pick either the heaviest of the light four, or the lightest of the heavier four. If you do this, your choices for a middleweight are Uranus - at 14 Earths - or - get this - Earth!

So, let’s just not use confusing terms like middle weighted to described planets more than half again as large as Saturn, which is a really massive planet.

Ok, enough fun. Overall, this is not a terrible press release like the one from UC Davis. This is ok, I guess. Where I’m having problems with it is that it is at several point misleading, and at a couple points maybe outright false. Press releases that are misleading or convey falsehoods as facts are harmful to science communication. It is too bad the astronomers involved in this release either couldn’t control the content of the release, or couldn’t improve upon it, because this release definitely falls into the category of harmful to the profession - just less so than some others.

Over at Cosmic Variance, Julianne alerts us to a commanding advantage of the iPhone if you work in the fields of physics, astrophysics, or orbital mechanics:

I’ve written before about my husband’s affection, or rather, obsession with Apple. Like all good converts, he feels compelled to proselytize, particularly about my perceived need for an iPhone. “But honey, you can check your email!” “Hey look! Google Maps knows where you are!”. I remain unconvinced.

However, the other day, he nearly got me:

“Did you know it can emulate the HP-15C?”

Be. Still. My. Heart.

The HP-15C is simply the finest piece of handheld computing technology ever.

The 15C is no longer made. On eBay, used ones sell for nearly the price of a new iPhone. Go over to Cosmic Variance to get your 15C emulator for iPhone, and sign the petition to get HP to bring the classic calculator back.

Oh, by the way - I’m pretty sure that the Bad Astronomer said some very nice things about the 15C at TAM 5.5, after telling a story about his first scientific calculator, which came with (gak) biorhythm software.

I have previously posted on the International Year of Astronomy - and I had kind of a mixed reaction to IYA overall.

Having stumbled upon the IYA website back at the beginning of January, my main reaction to it was that at the time, it was pretty heavy on bureaucracy, and pretty light on things that I thought would actually help astronomy EPO. I didn’t just seagull¹ the IYA - I offered constructive criticism.

Today I learn that Pamela Gay, one of the really truly helpful people in the world of astronomy education, has been hired into the IYA’s bureaucratic apparatus.

Let me say as clearly as possible: This is a good thing. A very good thing. This single move gives IYA more credibility in my mind than anything I’ve heard so far, including things the two people associated with it left as comments on my previous post.²

Pamela recalls some painful experiences she’s had in the past turning FITs images into play-nice JPEGs and other “standard” pc/mac image formats. I’ve had exactly the same problems. And she reports that NASA/ESA/ESO have come out with FITsLiberator as a Universal Binary (and Win compatibility too) - which is relevant to me, since I’m now doing most of my work of a new Macbook. This is indeed a Good Thing, and something that will help advance IYA’s stated goals, although it isn’t clear exactly what IYA had to do with the FITsLiberator update.

Pamela mentioned the IYA’s Portal to the Universe project (without linking, for shame), and I got my hopes up, thinking that maybe someone had taken to heart the plea from my last post on the topic (I’ve edited it in a few places to bring it up to date):

As I write, I have spent 65 hours 135 hours preparing an EPO presentation for adults on the history of astronomy that gets presented at CCSO next week³. If I’m lucky, I’ll get to give it at the Eagle River Nature Center sometime in the future - this is planned as a two-use program. There’s an outside chance it will get recycled in a few years and I’ll get a bit more mileage out of it.

The program starts with ancient conceptions of the structure of the universe and covers every really major astronomical discovery or theory since then. By “really major” I mean things as significant as heliocentrism, the cepheid period-luminosity relationship, the expansion of the universe, the cosmic microwave background, and the like. My presentation has 70 slides 95 slides, and all but two of them are images or animations. What has taken the most time has been (a) finding the illustrations and (b) getting the permissions to use them. (I know I can claim fair use - but sometimes I need permissions because the venue hosting the talk demands that I have them, regardless of the law; other times, I need permissions because it would be fair use to use the image in my talk, but not on the web or in the newspaper in promotion or coverage for the talk, etc, etc.)

What I really could use is a public domain or Creative Commons licensed image and animation library. Something that is captioned by experts so that I know exactly what I’m seeing in the image. For example, I don’t have a good animation of stellar parallax - there should be movies out there put together from FITS images that I can use. The movies exist, in varying quality, but getting permission to use a high quality, useful animation isn’t happening. There’s no animation that illustrates the origin of the cosmic background raditation that I can find. Even though I can picture how to illustrate it, I’m no artist. It is hard to find an illustration of the Keplerian thought transition from “orbs” to “orbits” - a fairly important advance in thinking about planets not as things affixed to spheres with rotate, carrying the planet along with it, but as things which are out in space attached to nothing and revolving in orbits.

Unfortunately, Portal to the Universe is not the image/animation library I had hoped. Portal to the Universe looks like it is going to be a super-cool, mega-feed-aggregator for everything good about astronomy. That’s great. I’m not against that. I just want more.

Pamela, IYA, please:

What I really could use is a public domain or Creative Commons licensed image and animation library, captioned by experts.

I’m not trying to be histrionic by using the big type. IYA obviously has some money to spend on improving astronomy outreach, and they’ve obviously got some political clout. Please start using that leverage to ask researchers to release significant images under Creative Commons or GPDL or some other free license.

I’m not alone. I’ve been associated with astronomy clubs for most of my life, and in each club, there are always five or ten people who are going out to talk to a school class or the Girl Scouts or similar groups once or twice a year - especially if they have kids of their own in the system. In the last five or ten years, as multimedia projectors have become common, the standards for presentations have risen sharply. As a consequence, these people are spending more time in PowerPoint or Keynote preparing their shows, and they are running up against the same problems I am. They ask: Should I just use the image and not tell anyone?

Usually you can do so, and do so legally. But what you can’t do is use it, and then (legally) give it to your pal in the astronomy club when he’s going to a different classroom to talk on the same subject. You can’t post the presentation file on the astronomy club website for everyone to use, for fear someone will object to the content. Even if we, personally, as individuals are willing to take the risk, people with fiduciary responsibility in the club (quite rightly) won’t allow it, due to that same risk.

IYA, if you can make a start of such a library, I, and people like me - and there are lots of us doing this independently in the trenches - will benefit by:

• Being able to share our presentation files without the fear of getting sued by some university bureaucrat protecting their “rights” to some image or other. I’m not saying it has happened, but I have heard stories about threats, and we’ve all heard about RIAA ruining peoples lives with lawsuits directed at the wrong defendant, demanding outrageous damages, etc. Give us a legitimate way to use the images and share presentations and dramatically cut the amount of preparation we have to do - that will advance what you are all about.
• Being able to do better education and outreach outside of our specialties. I have hundreds of thousands of images of asteroids taken with ground-based telescopes, because that is what I research - asteroids. I do not have even a single image of cosmic background radiation anisotropy that I know for sure I’m permitted to use. The good news? Since asteroids hit planets, and killed the dinosaurs, I’m often asked to talk about asteroids, not CMB anisotropy, so in those cases I have lots of cool images for those talks. The bad news? I’m also often asked to talk about the big bang, because that’s a pretty fundamental astronomical issue, and it is one that schoolteachers don’t always grasp enough to teach it well. (The captioning is important here - news release captioning is often mangled by institutional PR writers with no knowledge of the subject, and I often find that the information that goes with such images is a bit less helpful than it could be. I’m no cosmologist, but I’m not stupid either, and I’d benefit from an expert perspective on the kinds of issues we see streaming by in the feeds that basically just reproduce astronomy press releases. The proof of this are the large number of papers I get from arXiv when my interest has been spurred by a press release - I understand most of them.)
• One-stop shopping. I could probably cut my preparation time by more than half, because (a) I wouldn’t have to go google-surfing for images I can steal, and (b) I wouldn’t have to beg for permissions from dozens of different people, and keep track of when I’m getting referred to someone else for the permissions instead, when I’ve got permission, when I’ve been denied permission, etc. If I can cut prep time in half, I can (a) do three more EPO activities in the saved time, or (b) take some time off and not go crazy for doing so many EPO activities.

Institutions would benefit by preserving their copyright if they chose a creative commons - attrib - no derivative - no commercial license. (Oh, and by the way - I put my money where my mouth is. This blog is CC licensed. I’m also a magazine writer, and my writing has earned me some not insignificant money. If I can do it, I’m sure some astronomers can too.)

Thank you, IYA, for listening to my thoughts.

PS -

Last time I posted about IYA, people with the IYA asked me to call them on the telephone. Don’t take this personally, folks - but I am busy. I’m in the schools two or three times a week doing astronomy and physics education, and I’m not a teacher. I’m out in front of the general public six to eight times a year doing the same thing. I have a blog. I have a job. I’m in the inconvenient time zone of UT -9 (-8 for DST). And I tend to prefer my solitude anyway. But it isn’t that I don’t want to talk to you, its just that anytime I might call you I have five other things that are more important to do. If you want to talk to me, leave a comment and ask me to send my phone number - I’ll send it. It is easier to be interrupted than interrupt myself.

1. Seagull: to swoop in, crap all over everything, and fly away. [↩]
2. I didn’t allow one of the comments through, because of the number of phone numbers it contained. This blog attracts some readers that you just don’t want to give your phone number to. [↩]
3. It got presented, it was well received, it was great! [↩]

The University of Bristol has a press release out yesterday reporting that a Sumerian clay tablet provides an account of an impact event at Köfels, Austria.

I call bullshit. Here’s why, starting with some background information.

Köfels does not have a crater; it has what looks like a giant landslide, about half a kilometer thick and five kilometers in diameter. In the mid 20th-century, the impact hypothesis was raised to explain the formation. Apparently there is a lot of glass in the formation, which some geologists think could have been formed when rock melted in the landslide, and others think is more plausibly from an impact. There’s no doubt that other impact events have created quite a bit of glass. The age of the Köfels glass has been measured using radiometric methods, so we know the glass was formed between 8,000 years to 16,000 years ago.

Perhaps the strongest evidence for an impact origin of the Köfels structure is the reported presence of planar deformation features in quartz taken from the site. (But see the update at the end of the post!) PDFs, as they are called, are microscopic features of silicate (e.g., quartz, feldspar) grains, and they are basically very thin planes of glass arranged in parallel sets that have particular orientations with respect to the containing crystal’s structure. They are utterly diagnostic of impact events - no other geologic event can form them, not even highly energetic volcanic eruptions¹. They look like this (NASA image):

The presence of shocked quartz - quartz with PDFs - means that this quartz, at some time, was in the neighborhood of an impact event. If the big landslide-looking formation at Köfels was formed by impact, then the shocked quartz could have been formed then. Or it could be from an older impact, and was transported by later geologic events, such as huge landslides. The shocked quartz will survive a lot longer than an impact crater, given the way the Earth covers such structures up relatively quickly, so this may well have happened. However the shocked quartz got where it is found today, we know that it was formed when a meteoritic body impacted the ground. Shocked quartz does not form from a meteoritic airburst - a meteorite that explodes before impact - it requires a ground impact.

Science marches on, and the impact hypothesis to explain the origin of the Köfels formation fell out of favor as we discovered more and more about impacts. The main problem was the lack of parallels between the Köfels features and other known astroblemes - namely, there is no crater at Köfels, and there darn well ought to be if there is 8-16 kiloyear-old glass and shocked quartz from an impact event at the site. Here’s a picture of a smaller impact that is five times that age:

Notice how fresh and recognizable that crater is?

Currently, the consensus of scientific opinion is that Köfels is not from an impact. It is not listed in the Earth Impact Database, not even as a possible impact site. Googling “Köfels impact” turns up a zillion outlets parroting the Bristol press release, but there’s almost nothing else about it on the net.

So, where does this Sumerian tablet come in?

The researchers say the tablet dates from 700 BCE, or about 3,000 years ago. They hypothesize it is a copy of an earlier work:

With modern computer programmes that can simulate trajectories and reconstruct the night sky thousands of years ago the researchers have established what the Planisphere tablet refers to. It is a copy of the night notebook of a Sumerian astronomer as he records the events in the sky before dawn on the 29 June 3123 BC (Julian calendar).

I happen to have some software that can do that. Starry Night, Skymap Pro, or Stellarium, among numerable others, can do the job. So this isn’t rocket science. Anyone know where I can get a high-quality photograph of the tablet that I can use to test their hypothesis from my own reseources?

But a better question might be:

Assuming that the original source is a “night notebook” of a Sumerian astronomer, why is it being copied by a scribe 2,423 years later? No reason is given for this remarkable act in the press release, at least. Already it sounds a little fishy to me.

The press release continues:

Half the tablet records planet positions and cloud cover, the same as any other night….

Wait a second. Do we really know that half the tablet records conditions “the same as any other night?” Because if we do, that means we have a bunch of other examples of this genre of tablet to compare this tablet to. And if so, that’s fine, but then why does the press release say this:

A cuneiform clay tablet that has puzzled scholars for over 150 years has been translated for the first time.

They can either have their cake, or eat it: Either the tablet was mysterious and untranslated; or we can’t really know that this tablet is a typical nightly astronomical report of sky conditions, just like any other.

The problems continue:

…but the other half of the tablet records an object large enough for its shape to be noted even though it is still in space. The astronomers made an accurate note of its trajectory relative to the stars, which to an error better than one degree is consistent with an impact at Köfels.

Okay, I guess - something 500 kilometers away and 1 kilometer in diameter will be a tenth of a degree across, which is just about big enough to determine shape; and it could have been closer and still been in outside the atmosphere. And it is possible to record a trajectory to better than a degree using naked-eye methods.

It is also possible to integrate a bunch of orbits that intersect with Köfels, and it is plausible to believe that some of those orbits might be consistent with the observation of a celestial object that is hypothesized to be recorded in this copy of a hypothesized tablet that existed 5,000 years ago, and it is plausible to believe that some of these orbits would have the object out of Earth’s atmosphere when it was observable over Sumeria.

But really, this is beginning to look a bit like a house of cards, yes? Let’s read on.

The observation suggests the asteroid is over a kilometre in diameter and the original orbit about the Sun was an Aten type, a class of asteroid that orbit close to the earth, that is resonant with the Earth’s orbit.

The bit about the Aten asteroids being resonant is just wrong. Many are resonant, some more strongly than others; but Aten asteroids are defined as those with a semi-major axis of less than one astronomical unit. An AU is, in lay terms, the average distance between the sun and the Earth. A semi-major axis is simply the distance of the long axis of an ellipse, divided by two. Almost all Atens have orbits that cross Earth’s orbit - in other words, most Atens get both closer to the sun than Earth, and farther away from it, depending on what part of its orbit it is in. That’s all - you don’t need the asteroid to be in a resonant orbit to be an Aten.

And a resonant orbit certainly doesn’t lead to a craterless impact, as I initially read the following as claiming:

This trajectory explains why there is no crater at Köfels. The in coming angle was very low (six degrees) and means the asteroid clipped a mountain called Gamskogel above the town of Längenfeld, 11 kilometres from Köfels, and this caused the asteroid to explode before it reached its final impact point. As it travelled down the valley it became a fireball, around five kilometres in diameter (the size of the landslide). When it hit Köfels it created enormous pressures that pulverised the rock and caused the landslide but because it was no longer a solid object it did not create a classic impact crater.

What??

This is just preposterous.

First, you’re going to find plenty of evidence of the impact at Gamskogel if this were true. Any impact significant enough to badly disrupt an asteroid-type impactor, which is what the researchers hypothesize, is going to take out a big chunk of the mountain, cause all sorts of fracturing, landslides, and other highly noticeable effects. The physics of impact are such that, if the impact were truly strong enough to liquify or vaporize a >1 km asteroid, the mountain would have been converted into a crater - much like we see countless times on the moon.

Test of hypothesis number one: Is there a huge crater on the mountain, or has the mountain been obliterated by a huge crater?

The impact of an asteroid with a mountain will result in the classical shock wave in the impact medium and create an ejecta blanket. If the impact hypothesis is true, we should see planar deformation features on the mountain and ejecta more or less symmetrically around it.

Test of hypothesis number two: Is there shocked quartz on the mountain?

Test of hypothesis number three: Is there an ejecta blanket around the mountain?

Next, why would an impactor become a fireball? We all know that meteors in the process of burning up are hot, but they are not, literally, fireballs². The researchers claim that that an asteroidal-type meteorite, after clipping the mountain, was “not a solid object” - but why? And how? How do you get an asteroidal impactor hitting so solidly that it vaporized it, but so softly that it doesn’t shock quartz or create a crater?

Sorry, but you just can’t.

You don’t solve any problems by breaking up an impactor into a million pieces - it still impacts. So you end up with a bunch of smaller craters - the total energy is the same. Here’s an example of either a binary impactor, or disrupted impactor, on the Earth:

and an example on the Moon:

Supposing you can disrupt a 1-km asteroid impactor into pieces no larger than molecular size. What happens then? You still get craters:

That’s a microcrater in glass, too small to be seen by eye.

Maybe the press release is saying that the low angle of impact, supposedly of only six degrees, would not result in the formation of a crater. But that’s wrong too. Highly oblique impacts - thought to be considerably shallower than 6° - produce elongated craters:

So, there’s gonna be a crater, or two, or a billion, no matter what you do to the impactor³. Just because the asteroid “clips” a mountaintop on its way to its final resting place doesn’t mean there will be no crater. There will be one, or many, period.

Test of hypothesis number four: Go find the crater(s).

Test of hypothesis number five: Go find fragments of the impactor. There will be some, even if the main impactor vaporizes.

Let’s read on:

Mark Hempsell, discussing the Köfels event, said: “Another conclusion can be made from the trajectory. The back plume from the explosion (the mushroom cloud) would be bent over the Mediterranean Sea re-entering the atmosphere over the Levant, Sinai, and Northern Egypt.

“The ground heating though very short would be enough to ignite any flammable material – including human hair and clothes. It is probable more people died under the plume than in the Alps due to the impact blast.“

Ok, so there’s no crater because the impactor “wasn’t solid,” but there was enough ejecta - which only comes from craters - to kill people, and cover an area thousands of miles around, including northern Egypt and the Levant, where we should be able to go today and find - ummm, ejecta.

Test of hypothesis number six: Let’s go find ejecta, or evidence of widespread burns, in strata that we can date, using, e.g., pottery shards, to around 3100 BC in multiple archaeological digs in both Egypt and in the Levant. The strata should be iridium-enriched compared to terrestrial facies, ought to include shock products if the impact were powerful enough to spread material over that wide an area, and ought contain impact glass.

Ok, we’re done. Just to sum up, here’s why we can be pretty sure this press release promotes a wrong conclusion.

The researchers hypothesize:

• That Sumerians made regular celestial observations (probably true);
• One of them observed a large body very close to Earth before it had entered the atmosphere (very improbable - whereas seeing a very bright meteor is not only probable, but certain, if you keep looking)
• They recorded the trajectory to an accuracy of +/- one degree or less (plausible)
• The tablet they recorded this on was reproduced by a scribe 2,423 years later (possible, but why?)
• Even though apparently no other nights’ observations were similarly copied (why not? There would have been TONS of interesting stuff, and just as correlated with significant happenings on Earth - not by causation, but by coincidence)
• And this tablet has never been translated before (I’ll stipulate that this is true even though I don’t really know)
• Two researchers - one a space infrastructure engineer, the other a rocket engine engineer, and neither linguists - translated it (huh? how?)
• And the tablet records an impactor (maybe)
• even though the impact glass found at the site is 8,000 to 16,000 years old (not 5,000 years old as the hypothesis says)
• And the impactor was a >1 km Aten asteroid (seriously, people, it requires several hours or days of precise, modern astronomical observations to determine if an asteroid is an Aten - you need either triangulated observations over a short time, or observations over a longer period of time, to extract that kind of data from the observations they say the Sumerians recorded)
• And that impactor landed at Köfels (maybe, but you need triangulated observations of incoming impactors to really determine where and if a possible impactor landed, because you can’t tell celestial distances or radial velocities - motion toward or away from you - by just looking)
• But not before “clipping” a mountain (oh, come ON! can we say “ad hoc hypothesis?”)
• Which turned it into something other than a solid (I’ve heard of shock melting, but turning an entire 1 km impacting asteroid into a liquid with a glancing blow with a mountain is beyond the pale, and turning it all into gas would be even more ludicrous)
• Which then created no craters when it landed (it still should have)
• But which did distribute ejecta all over the eastern Mediterranean (you don’t get ejecta without a crater)
• Which ejecta has not been found anywhere in the eastern Mediterranean (ouch)

I’ll add one more thing: This “research” hasn’t cleared peer review - the authors are trying to sell a direct-to-paperback book for $25 (USD). The press release says it is being published by Alcin Academics, but I can’t find them on the web and I can’t find any other book they’ve published. A quick look at the Amazon page for the book shows that the real publisher is WritersPrintshop - a self-publishing company. I’m thinking if this were a plausible hypothesis supported in a well-written book, they’d have gotten a real publisher to release it.

I’m not buying it - the book or the zany hypothesis. If anyone wants to change my mind, send me a copy of the book, and I’ll read it and reconsider.

Oh - and one more thing: Shame, shame on you, PhysOrg for credulously running this ridiculous story but ignoring the asteroid names announced last week.

Sources for Köfels background information:

• Graham, Bevan and Hutchison, “Catalogue of Meteorites”, 4th Edition, (1985)
• Kurat, Richter; Meteoritics, vol.4, p.192, 1969
• Störzer et al.; Meteoritics, vol.6, p.319, 1971

Update: I’ve been pointed to some additional references regarding the Köfels formation, which somewhat changes what I’ve written above. First, shocked quartz, with PDFs, have not been found at Köfels as some have claimed; quartz with lamellar deformation features typical of tectonic processes were found instead. Also, the Köfels formation was not a single landslide, but a result of several landslides at different times. These are both further blows to the already discredited impact hypothesis for the origins of the Köfels formation, and casts even more doubt onto the conclusions that Sumerians observed a greater than 1 km wide Aten asteroid that impacted at Köfels.

New references:

• Deutsch, Koeberl, Blum, French, Glass, Grieve, Horn, Jessberger, Kurat, Reimold, Smit, Stoffler, Taylor; The impact-flood connection: Does it exist? Terra Nova. vol. 6, 1994, pp. 644-650.
• Hermanns, Blikra, Naumann, Nilsen, Panthi, Stromeyer, Longva; Examples of multiple rock-slope collapses from Köfels (Ötz valley, Austria) and western Norway. Engineering Geology. vol. 83, no. 1-3, 2006, pp. 94-108.

The “French” in the first one is, I’m pretty sure, the same Bevan M. French who has done so much geological work on the moon and terrestrial planets.

There is additional discussion of the geologic findings here, where these two works are also cited among others, and I think the person who brought them to my attention is a member of that forum.

Update #2: Some very specific claims were raised by Mark Hempsell in the comments below; I’ve responded to them here.

1. The can be, and are, formed by nuclear explosions, however. [↩]
2. Amateur astronomers’ slang is to call bright meteors “fireballs,” but this refers to visual appearance, not physical constituency. [↩]
3. It is ridiculous to assert a 100% efficient vaporization of the impactor. The Barringer impactor was vaporized, but fragments of the impacting body remain. [↩]

On Thursday, University of Oxford reported on the discovery of the largest impact crater in Britain. The 1.2 billion year old impact event is believed to have taken place near the northwest Scottish town of Ullapool.

According to the release, material long believed to be volcanic in origin turned out on closer inspection to be an ejecta blanket from the impact. The ejecta zone is about 50 kilometers across.

Analysis of the material found the tell-tale iridium concentrations characteristic of large impact ejecta (and most famously associated with the Chicxulub crater, the KT boundary impactor that contributed heavily to the extinction of the dinosaurs and many other taxa). They also observed shock fracturing in some of the samples.

Apparently some of the ejecta blanket is exposed on the west coast of Scotland, which is pretty nice. Most impact events on Earth have been covered by more recent formations, and impact materials can only be accessed by fairly expensive drilling. To have the material exposed, and in a relatively convenient location to visit, is pretty nice for those studying impact geology.