Archive for the ‘Skepticism’ category

The Tubes of Mars

October 27, 2010

Last week was my birthday, and I unexpectedly got a gift in the mail from my cousin. We don’t normally exchange birthday gifts, but she came across a t-shirt called “Tubes of Mars” and just had to buy it for me. Apparently, this line of shirts is capitalizing on various wacky conspiracy theories and they decided to use one of my favorites, the “glass tubes on Mars” idea.

The shirt itself has a swirly-looking abstract design on it, but then down in the corner it has a caption in fine print explaining:

Photographs taken from Martian orbit reveal what appear to be miles and miles of ribbed ‘tubes’ on the surface of the red planet. It is estimated that these tubes have diameters of close to 600 feet. Some have tried to explain these formations as a the result of geological processes. Others believe they are organic in nature. Yet some are convinced the tubes may have been constructed.

If you’re not familiar with this hoax, let me explain, starting with a picture.

Here's a HiRISE view of some channels on Mars full of aeolian ripples.

See the numerous light-toned ridges arrayed along that canyon floor? There is a group of people who claim that these features are actually the support struts of transparent tubes that crisscross the martian surface. I’ll grant that if you have no idea what you’re looking at, these things might sort of look like a tube of some sort, but it’s actually an illusion. The light-toned ridges are ripples of wind-blown material, likely coarse sand or gravel. These are seen all over the place on Mars, and they don’t always look so tubular. Heck, the Opportunity rover has been driving across ripples like these for years! The thing that is confusing people is that these ripples are extremely common in canyons, and because the canyons funnel the surface winds so that they blow down the length of the trough, the ripples are oriented perpendicular to the canyon walls. If you look closely you can see that these are clearly wind-blown ripples. Take this HiRISE image for example:

Here's a HiRISE view of some channels on Mars full of aeolian ripples.

The channels in this image are filled with aeolian ripples. If you were really determined to see a tube, I suppose you could at the scale shown above, but if we zoom in even more that explanation disintegrates:

You can see here that the larger ripples break up into more complicated ripples toward the edges, and that there is a secondary wind direction forming small ripples perpendicular to the big ones.

I’ve always found the belief that these features are some sort of glass tubes on Mars to be both funny and sad at the same time. It shows a complete lack of understanding of the very interesting geology at work on Mars (and Earth), along with a somewhat disturbing willingness to see evidence of outlandish claims and conspiracies everywhere. Those of us in Mars science are all too familiar with this. There’s a long tradition of seeing what you want to see on Mars, going all the way back to the famous “canals”. These days, no scientists really think there’s macroscopic evidence of life on Mars, but I think there is still a very strong desire among scientists and the public for early Mars to have been “warm and wet” (a.k.a. Earth-like). Maybe it really was earth-like, but maybe it wasn’t. We all need to be vigilant and make sure the way we want Mars to be doesn’t cloud our conclusions.

Jaded by Mars Organics

September 11, 2010

So, you may have heard the news making the rounds last week that a new analysis of the Viking data suggests there may actually be organics and (dare I even say it?) life on mars! Yawn. Consider me underwhelmed.

The gist of the story is this: A long-standing mystery in Mars science has been why the Viking instruments were unable to detect any organic molecules on Mars, not even at a level that would put Mars on par with the moon. Now, 30 years later, the Phoenix lander discovered the perchlorate molecule in the arctic martian soil. Perchlorate is a powerful oxidizer, and by heating a soil sample containing organics and perchlorate, you’re bound to destroy the organics. So, if there were perchlorates at the Viking site, then maybe the Viking instruments destroyed the very organics they were trying to find! The few traces of organic compounds detected by Viking were interpreted as residue from the chemicals used to clean the instrument, but the new results show that organics oxidized by perchlorate can also form those compounds.

To me, this sounds pretty familiar. See, as I understand it, the leading theory for what happened to the organics on Mars to bring them to levels below the moon is that some unknown oxidizing agent had destroyed the organics. So, now we know what the oxidizing agent might be, but it seems that the prevailing theory still holds. I suppose the excitement comes from the possibility that the organics could remain intact until the soil is heated, and so low-temperature investigations might detect them. But the modeling in the paper did not consider that the organics were sitting at the Martian surface for perhaps billions of years. Yes, heating in the oven might destroy the organics, but that may be meaningless if they were all broken down millions of years ago by UV radiation. As for the traces of organics that Viking did detect, as the press release mentions, they had the same Cl isotope ratio as Earth. Now, it’s not impossible that Mars has the same ratio as Earth, but it would be a coincidence. Invoking coincidences in science makes me uncomfortable.

A few years back, during my summer internship at NASA Academy, I earned the nickname “aguafiestas” which translates to “that guy who ruins all our fun”.  I earned the nickname for debunking some internet hoax emails that my friends were sending around, but it’s a nickname I wear proudly.

So, maybe I’m being an aguafiestas again with this press release, but I just can’t get that excited about the announcement. I will say that I am really looking forward to the results from the SAM instrument on MSL, which should be powerful enough to detect organics wherever they are hiding on the Martian surface. I’m not naive enough to claim that it will answer all our questions, but it might. Even an aguafiestas can hope!

Absence of Mind on the Daily Show

July 14, 2010

I normally like the Daily Show, but I had a problem with the July 8 interview with Marilynne Robinson about her new book, Absence of Mind . I had never heard of this book before, but it appears to be a discussion of the conflict between science and religion, with the message that scientific thinking does not fully take into account the complexities of the human mind.

Okay, interesting topic. But I was dismayed during the interview at how both John Stewart and Marilynne Robinson built up a caricature of science to knock down. Stewart claims: “The more you delve into science, the more it appears to rely on faith.” As an example of this, he uses antimatter. It’s pretty clear that he meant dark matter and not antimatter as he jokes about not being able to detect it and just having to trust that it’s there. The problem is he’s still completely wrong. Dark matter can be, and has been detected based on its gravitational influence. There’s no faith involved here! It all goes back to the simple observation that galaxies were spinning too fast for gravity from the visible matter to hold them together. So astronomers suggested that there might be some other form of matter. And now, in cases like the bullet cluster, the dark matter has been detected. To draw a parallel between that and the notion that a god created the universe doesn’t really make sense to me. Dark matter is a testable hypothesis, god isn’t.

But I’ll accept that Stewart was making a joke, and that neither he nor Robinson are scientists so they might get dark matter wrong. That doesn’t change the fact that I am deeply suspicious of the book’s premise. From what I saw on the interview and what I have read in reviews of the book, it sounds like the entire premise comes from a misunderstanding of science and a desire to boost the self esteem of those who can’t deal with the endless demotions that science seems to throw our way. But science isn’t actively trying to make us feel small and insignificant, that’s just how the universe is. I’m reminded of a quote by Carl Sagan, who talks a lot about this sort of thing:

Is our self-esteem so precarious that nothing short of a universe custom-made for us will do?

As for the claim that science unjustly devalues the individual and those experiences that occur within the mind, well, I wonder exactly how she suggests we incorporate those into our theories. It’s not possible to fully communicate the richness of our internal thoughts to someone else, or to record them as data to be analyzed. We’re stuck with clunky tools like speech and art and music. Again, I’m reminded of a quote:

Human speech is like a cracked kettle on which we tap crude rhythms for bears to dance to, while we long to make music that will melt the stars. -Gustave Flaubert, Madame Bovary (1857)

It’s not for lack of trying that science has failed to take into account the depth of the mind and the individual experience. I’m sure psychologists and neurologists and many other -ists would love to have that information available. We’re just getting to the point where brain scanning technology can identify thought patterns with various emotions. But being able to say “Oh, that person is experiencing religious rapture” or “hey, look, this person is in love” isn’t quite the same as the actual experience.

Robinson brings up the point of altruism as a problem that science can’t explain. It’s been a few years since I read it, but I believe Richard Dawkins addresses this pretty thoroughly in the Selfish Gene. I’m probably going to butcher the argument, but basically, altruism could come about from an instinct to protect those to whom you have formed a close social bond, which until quite recently, evolutionarily speaking, would have been likely to be either related to you or your mate.

It’s certainly interesting to think about how science might have unintentionally become blind to so much of what makes us human, but to expect science to be able to use our subjective experiences to come to any meaningful conclusions is asking an awful lot. In fact, science works precisely because it does not use subjective, individual experience as the basis for drawing conclusions about the world! If it did, it wouldn’t be science anymore.

To be fair, I haven’t read Robinson’s book, and it’s entirely possible that she has counterarguments to everything I have said here. I’m probably grossly misrepresenting her arguments based on the minimal information in the Daily Show interview and in reviews. It sounds like a genuinely interesting and intellectually challenging read, and I suspect I actually agree with her on a lot of things. But it also sounds like there are some fundamental flaws in her argument. I’d love to hear from anyone who has read the book and can come to its defense, but based on what I’ve seen so far, it strikes me as a misrepresentation of science, and I am disappointed that the Daily Show wasn’t just a little more critical of it.

More TED skepticism: Is science news the most important news?

March 31, 2010

Only days after a TED talk about Mars inspired this post correcting some of the misconceptions in the talk, another TED talk has me scratching my head. This one is by Kirk Citron, editor of “The Long News”, a project concerned with winnowing the few news stories from current events that will actually be seen as important 100 years or more from now. In his very brief talk he gives examples of news stories that he thinks probably won’t be remembered for long, such as the heroic splash landing of a plane on the Hudson river. But what I really thought was interesting was that he chose science news stories as some of the most significant.

Now, don’t get me wrong: a lot of science news is genuinely more important than the inane stories of scandal and petty politics that dominate the 24 hour news cycle. But I also know that science press releases tend to exaggerate the importance of the research being done. Science news invariably reports every incremental advance as a revolutionary discovery. This is, sadly, standard practice: scientists (and the associated media relations folks at their home institutions) have gotten good at this because that’s how you get funding. So when I see stories such as the ones that Citron cites (nano-bots being injected into mice to cure cancer, a “robot-scientist” making a discovery, the discovery of water on the moon) I am skeptical.

Regarding nano-bots: I remember reading a Scientific American back in middle school about this technology. Yes, it may revolutionize the future, but my point is that articles like the one that Citron mentioned have been coming out for years. Individual articles will probably not be remembered 100 years from now.

And of course, his special mention of the water on the moon story tells me that he doesn’t fully understand the science stories he has selected. The discovery of water on the moon is scientifically fascinating, but as far as I know, the amount of water present there is pretty miniscule and isn’t going to suddenly spur a rush to colonize.

Much like the Mars talk that I criticized, I agree with the message here, but disagree with the particulars. Call me cynical, but I don’t think that most of the science and technology stories that he chose will be remembered 100 years from now. Maybe a handful of them will grow to fruition and we will eventually see nano-bot medicine or moon colonies, but many more of them will fall out of favor, or some better way to do things will be discovered.

So is science news the most important news? I generally would have to say no. Obviously I think it is more important than the vast majority of day-to-day news, but major world events probably trump your typical breathless science news stories. Science inherently keeps good records, so it does have a better chance of being remembered, but despite what press releases might say, it’s a rare scientific discovery that will be remembered 100 years down the line.

TED Talk: Why we need to go back to Mars

March 25, 2010

I recently started subscribing to the TED talk RSS feed, and I really love coming home every day after work and listening to smart people talk about cool ideas. If you aren’t familiar with TED, you should be. Most of the talks are fantastic and very thought-provoking. So you can imagine I was excited when I saw that today’s talk was about Mars!

The talk was given by Joel Levine, the principal investigator for the proposed ARES mission, which is a rocket-powered airplane that would fly for a couple of hours on Mars and study the atmosphere, surface and subsurface.

He starts off with an overview of Mars exploration history, describing the Mariner flyby in 1965, followed by images from the Viking orbiters and landers. He says that the Viking landers returned the first images ever from the surface of another planet, but that’s actually not true! That achievement actually belongs to Venera 9, which, astoundingly, returned photographs from the surface of Venus in 1975! Everyone forgets poor Venus.

Levine goes on to talk about some of the stunning topographic features on Mars, highlighting Olympus Mons, Valles Marineris and the Hellas basin as the largest volcano, canyon and impact crater in the solar system, respectively. If you really want to be pedantic, Olympus Mons is the tallest volcano, not the largest, but it’s not really a big deal because Mars also has the largest one (Alba Patera). But what really made me pause for a moment was that Hellas is not the biggest crater in the solar system: the South Pole Aitken Basin on the moon has a diameter of 2500 km, 400 km larger than Hellas!

He continues and talks about the mysterious crustal magnetism on Mars and the fact that all of the water on present-day Mars is in the form of ice, and all of this is fine, but then a slide comes up which Levine claims shows “recent” photos from the Mars rovers with evidence of very fast-flowing water on the Martian surface. The only problem is, the images on the slide are all orbital images! I can’t say for sure but I think they are from the MOC camera, which stopped functioning in 2006, three years before this talk was given. Yes, the images show features that could be due to ancient flowing water, but they are certainly not from the rovers, and they’re not very recent either.

I got even more suspicious when Levine showed this picture of a crater filled with ice and claimed that it was taken a few weeks ago and had not yet been publicly released. The only problem is, I remember seeing that picture years ago. A quick web search reveals that it was released in a 2005 press release. Levine also misspeaks and says that the crater is filled with liquid water, but immediately corrects himself so I’ll let that slide. I’m baffled by his claim that it is a never-before-seen image though.

Credit: ESA/DLR/FU Berlin (G. Neukum); Image released: 2005

Shortly after the icy crater image, Levine makes a very strong claim that Mars once had oceans. He doesn’t equivocate at all, he states this as a fact. I find this to be very misleading. Yes, there are some hypotheses about a northern ocean on Mars, but the evidence just is not there to make such a definitive claim, and to pretend that it is gives people an incorrect impression about the Mars community’s consensus.

Even worse, later on in the talk, he claims that the northern lowlands are smooth because they were protected from impacts by an ocean. This is patently false. Oceans are not an effective protection against impacts and if you think about it, you’ll see why. The average ocean depth on earth is 2.3 miles. For comparison, the object that killed the dinosaurs was at least 6 miles in diameter and was traveling at tens of miles per second. It went through the ocean like it wasn’t even there.

Also, there is evidence for craters in the northern plains. They have been buried but they still are just barely visible in elevation data. Of course, an ocean would be one way to bury a huge expanse of the surface, but if the ocean isn’t thick enough to block impacts, then the burial must not be very old, and all evidence points to the water on Mars being a very ancient phenomenon.

Ok, oceans aside, Levine goes on to talk about the recent detections of methane on Mars. He summarizes the results well enough, but draws a misleading parallel with the earth. He says that 99.9% of Earth’s atmospheric methane is biogenic, which may well be true. But that doesn’t mean that life is the only possible source of methane on Mars! I don’t know the exact numbers involved but it would have been much more informative if he had compared the estimated amount of methane on Mars to the estimated amount from abiotic sources on the earth.

The second half of the talk focuses on the ARES Mars airplane mission. I have actually visited the lab in Langley that works on this concept and seen the models of the plane. It is undeniably really cool, but I am not convinced it is the best way to explore Mars. The problem with an airplane is that you need active control to keep it from crashing. Of course the technology exists to fly planes automatically, but to do so on Mars could be difficult. And even assuming that you can get the plane to fly automatically, it would only last for a couple of hours at most. It would collect some fantastic atmospheric and magnetic field data, and some very nice images and video, but it would only be able to cover a few hundred kilometers.

I think if you want to fly something on Mars it should be a balloon. The thin atmosphere is not ideal for a balloon, but they have the advantage that they fly without any active control: they’re lighter than air! It would be a slower ride, for sure, but it could last much longer than an airplane, and the winds could carry the balloon long distances.

In case you couldn’t tell, I was disappointed in this talk. For most people, it will be very enjoyable and they will probably learn something about Mars and about a cool proposed future mission, but the talk also had a lot of misinformation in it. Some was very minor and innocent, but the certainty with which the ocean hypothesis and the biogenic origin of methane were presented struck me as misleading.

I am all in favor of getting people excited about exploring Mars, but we should not give them the wrong impressions about the current state of knowledge. There’s plenty to get excited about without distorting the truth, whether it is intentional or not. That’s why I decided to write this blog entry. Is some of it pedantic? Yes. But I wanted to set the record straight so that maybe a few people get a more accurate picture of the red planet.

AGU 2009: Day 3 – Astrobiology and Society

December 20, 2009

Wednesday was full of particularly interesting stuff: in between the Venus and moon talks there was also the Sagan lecture and an afternoon session about astrobiology and its implications in society.

The Sagan lecture was given by Tori Hoehler, a scientist at NASA Ames. He discussed the fundamental thermodynamics behind life, and showed that even if alien life relies on completely different molecules, there are basic requirements, such as the availability of free energy, that should be universal because they are rooted in the way the universe works. To paraphrase, he said: Life must evade the decay into equilibrium by reproducing extremely low probability results. There is a lot of thermodynamics behind this, but everyone has common sense experience with it. The world tends toward entropy unless energy is applied. Just take a look at the nearest college dorm room.

The DNA molecule is an incredibly complicated "aperiodic crystal" that is highly unlikely to form spontaneously. Energy is needed to make unlikely things like DNA assembly happen.

Hoehler used real world examples showing that living systems, be they simple bacteria colonies or all the complex cells involved in a human being, tend to grow until they are using all of the free energy available. There is a certain minimum amount of energy required to add a new piece (such as a cell) to the system, so the system can’t grow unless that amount of energy is available.

Tori concluded with a quote from Carl Woese: “Organisms are resilient patterns in a turbulent flow.” Hoehler argued that when thinking about biosignatures, we need to look at the fundamental requirements of any life. Regardless of its specific chemistry: energy use is the ultimate biosignature.

Later in the afternoon on Wednesday there was a really thought-provoking section about the societal implications of astrobiology. One of the first talks that I saw in the session was by David Koch, discussing the Kepler telescope. Kepler is a mission designed to stare at a single large patch of the sky for years, monitoring the brightness of hundreds of thousands of stars. Why? Well, occasionally a star will have planets that orbit in just the right configuration so that they “transit” – pass between their star and Kepler’s detector – blocking out a tiny fraction of the star’s light. Kepler was specifically designed so that it will be able to detect even the tiny dip in starlight caused by an earth-sized planet passing in front of a sun-like star. Koch showed an example of Kepler data, as compared with ground-based data of a star with a known transiting giant planet. The ground-based data was very noisy because of the turbulent atmosphere, but the Kepler data was so good that it looked like a solid line rather than a series of data points. The Kepler data was good enough that you could see the change in brightness as the planet went through phases like the moon. Koch also showed a tantalizing signal from a binary system that may have a planet orbiting both stars, much like everyone’s favorite binary-orbiting plant, Tatooine.

Sunset on a world orbiting binary stars. However, the planet detected by Kepler is likely a gas giant, not a rocky world like Tatooine. Image copyright Lucasfilm Ltd.

Next, Jacob Haqq-Misra, author of the new book “Planetary Messenger”, talked about how life and climate are intertwined. One example of this was the early climate, when the only life was methane-producing bateria. Methane is a powerful greenhouse gas, and so the global climate would warm rapidly with a world full of methane-making critters, but methane also undergoes chemical reactions when exposed to UV light and forms a thick haze. Just take a look at present-day Titan for proof of this! The haze would eventually get thick enough to cool the planet’s surface, balancing out the warming due to methane and preventing the planet from overheating.

Of course, then along came oxygen-producing life, which destroyed the methane and organic haze and poisoned most ofther forms of life, relegating them to dark anaerobic places like the stomachs of cows. Haqq-Misra also pointed out that the modern climate is pretty unusual: we have ice caps. Models suggest that Earth typically is quite warm, with no ice caps even at the poles, or it enters a “snowball” phase, where everything freezes up and ice extends down to the equator. In either case, live persists, and it may be the action of life that nudges the Earth out of these extremes. Haqq-Misra’s bottom line was that life is extremely resilient and can have a powerful effect on climate. Modern-day climate change could have serious consequences for humans, but life in general will adapt in the long run. “We’re not saving the world, but ourselves,” he said. It’s not quite that simple, since many species other than humans are threatened by climate change, but his basic point still is valid.

The Earth likely oscillates between a “snowball” and “hothouse” climate, with life-driven cycles, particularly the CO2 cycle, playing a major role.

The last few talks in the session strayed from science into social science and philosophy. Linda Billings spoke about the relationship between astrobiology and culture. She pointed out that astrobiology has gained credibility from large agencies like the National Research Council, and has always been popular with the public, but that the public and scientific perception is somewhat different. The public tends to assume ET life is common and like us, while science focuses more on extremophiles and the origin of life. One thing that I wish she had addressed a bit more was whether the public perception of ET life is necessarily a bad thing. Yes, there are powerful misconceptions to work against, but the public’s interest in astrobiology makes it a perfect “entry point” into all sorts of science!

The last few talks in the session considered the interplay between astrobiology and religion. Richard Randolph, presenting for Ted Peters who couldn’t make it, showed the results of a survey asking the question “Could the confirmation of another civilization in the universe cause a religious crisis?” The findings were not that surprising: Religious people did not think it would cause them to lose their faith, but were somewhat more likely to think that other people might lose faith. Non-religious people were almost all sure that such a discovery would cause religious people to have a crisis of faith. I would like to see the results of the survey if the word “crisis” was removed from the questions. I suspect more people would be willing to admit that discovering ET would make them think hard about their religion, but that they wouldn’t consider that a “crisis” of faith.

Next, Connie Bertka talked about astrobiology and evolution. She said that we really can’t avoid discussing science versus religion because, to paraphrase, “nature and creation are no longer purely in the theological domain”. Thus, she said that astrobiologists should encourage dialog with religious people. I think it’s a fine line to walk. We don’t want to give people like creationists legitimacy by engaging them on equal ground, but we equally can’t just avoid the interface between religion and science.

Finally, Richard Randolph discusses the Christian ethical implications of astrobiology. He asked two primary questions: What ethical obligations would Christians owe non-intelligent extraterrestrial life? and Is there a Christian obligation to spread life in the universe?

Based on his reading of Genesis, Randolph extended the common interpretation of humans as “stewards” or “god’s authority on earth” to extraterrestrial life. I was disappointed that he so obviously avoided talking about the elephant in the room for this issue though. Sure, the bible gives us stewardship over extra-terrstrial microbes. He even said that predation, in moderation, is “acceptable” just as it is for life here on earth. That’s all well and good. But what happens when we find aliens who are as smart or smarter than us? Does the bible give us stewardship over them? Permission for “predation in moderation”? Why would a creator make mere humans stewards over equally intelligent or possibly much more advanced species?

Ok, we are stewards over alien microbes, but what if we meet these guys?

As for the obligation to extend life in the universe, Randolph said that, since the bible repeated describes creation of life as “good” then by extension, spreading that life elsewhere qould also be good. Thus he said that there was “qualified affirmation” of the assertion that we are obliged to extend life elsewhere. Again he dodged a big question: do we extend terrestrial life at the expense of possible more primitive extra-terrestrial life? (a.k.a. when is it morally justified to terraform Mars?) What if spreading terrestrial life is at the expense of more advanced ET life?

It was refreshing to have these more philosophical talks after so much science. I may not have agreed with much of what Randolph said, but it definitely made me think, and it was a good reminder that science does not operate in a cultural vacuum.

“Alien Skull” on Mars

May 6, 2009

PD*28522608

Are you kidding?!

Guys. That’s a rock. A chunk of vesicular basalt to be specific. As far as pareidolia goes, it’s not even very good! I had to stare for a while before I saw a face. The human brain loves to see familiar shapes in everything, so it’s pretty easy to find examples of rocks on Mars that look like anything you want. Here, take a look at this annotated picture of Mars put together by Eric Hartwell over at the Unmanned Spaceflight forum. Mars is apparently crawling with various forms of life! (click for a larger version)

pia10216_left_detail


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