Sulfur gases from our _____ have a most unpleasant odor. But why?

Fill in the blank here: 

"Beans, beans the magical fruit, 

the more you eat, the more you ____."

Do you remember that one? It was pretty common for my cousins and I when we were children. I recall at one point thinking of the "toot" like it was a tug boat's whistle in a harbor.

Let's try this one:

"Beans, beans, they're good for your heart,

The more you eat, the more you _____."

Okay, that one's pretty direct. Fart, toot, rip gas, bust ass, cut the cheese, break one lose, let one rip, send a bouquet, blast your chair, trouser cough: we have lots of ways to describe flatulence. One that I remember from my early adolescence was "doorknob": if you farted and someone said the word "doorknob" before you could say "safety" then you had to run as fast as you could to find and then touch a doorknob while your friends would do their best to pummel you. I know, I know... the stupid things that young boys do.

What is it about flatulence that seems so darned funny in some situations and absolutely disgusting in others? For that matter, why do farts smell bad?

The answer to the latter question is pretty simple: sulfur. 

Well, that might be a bit misleading. It's been thought for some time that some nitrogen-containing organic compounds contributed some of the odor to farts (most of these would smell something like the naphthalene in mothballs), however most recent research on the odors of flatulence points to volatile sulfur compounds (VSCs) as being the primary cause of "the big stink". Articles such as those of Suarez and colleagues (1998) and Tangerman (2009) point to hydrogen sulfide, methanethiol, and dimethyl sulfides as the primary agents of those smelly fart odors.

You may already know that sulfur is my favorite chemical element (and not just because my research involves sulfur). So let's talk about why sulfur makes our "booty belches" stink.

German peasants farting at Pope Paul III from
Martin Luther's "Depictions of the Papacy" (1545)

A fart, by any other name...

The majority of the gases that make up flatulence have no odor whatsoever. The portion of our flatulence that smells, the VSCs, make up less than 1% of the gases that come out. 

The other 99% or more of a fart is composed of gases like nitrogen, carbon dioxide, hydrogen, oxygen, and methane (many people think that methane has a "gassy" odor, but that's actually not true; pure methane has no odor). This image below, from a post on the Chronicle Books Blog, shows the primary composition of flatulence:

Image of primary fart compositions taken from Chronicle Books Blog

The gases in our "thunder from down under" come from three primary sources: atmospheric gases, undigested food material, and microbial metabolisms. The lattermost are the most important in making our noxious stenches. 

Life on Earth is utterly dominated by microorganisms. We might have developed civilization and science, but microbes still beat us in numbers by far. Indeed, the number of microbial organisms living on and inside of us outnumber the cells of our own bodies by anything from 10 to 1 up to 100 to 1. A lot of the processes that occur on our skin and in our guts are driven by the microbes who live with us. There can be over 1000 different microbial species living in our guts. These organisms help us digest our food: many of them ferment undigested carbohydrates to produce molecules that we can then use. Many of the dominant gases of our flatulence come from the processes of fermentation by our gut flora, especially hydrogen, a byproduct of fermentation. 

The action of sulfur-metabolizing microbes (such as sulfate reducers) is what causes the production of the malodorous sulfur-containing gases in our guts. In many cases, these microbes will pair the oxidation of hydrogen gas with the reduction of sulfur (from sulfate and from sulfur-containing amino acids), which is why we call them hydrogenotrophs. By consuming the hydrogen byproduct of fermentation, these sulfur reducing microbes form a symbiotic relationship with our other gut microorganisms. Thanks to that symbiosis and the processes involved, our gut microbes and our bodies benefit while our friends who have to smell the stench from our trouser trumpets are not so lucky. 

Here's a GIF showing the number of microbial species that can be found in or on various parts of our bodies:

So why do sulfur gases smell so bad?

I've been working on a project studying sulfur for so long that I've become accustomed to the smell of hydrogen sulfide. We usually say that hydrogen sulfide smells like rotten eggs, but that's not quite fair: the smell of rotten eggs includes hydrogen sulfide but also has other sulfur gases that make for a more repulsive odor. In fact, the smell of rotten eggs is much closer to the smell of farts than the smell of pure hydrogen sulfide gas. Still, there's not really another good way to describe the smell of hydrogen sulfide to most people. That's probably due to the fact that when we smell sulfide gases, we tend to do our best to get away from the odor. But why?

Season 2, episode 12, of Neil deGrasse Tyson's podcast Star Talk Radio was called "Appetite for Destruction" and featured an interview with Peter Ward, a paleobiologist and astrobiologist at the University of Washington (Peter Ward's book "Life as We Do Not Know It" rekindled my personal interest in astrobiology during my early college years). Tyson and Ward spoke about Ward's then recently published idea, The Medea Hypothesis, which is his consideration of the general relationship between life and the planet. There's a point in the episode where Tyson and Ward discuss hydrogen sulfide as it relates to global climate change and mass extinctions. That's when Peter Ward says this (roughly transcribed):

"Flatulence is essentially hydrogen sulfide... a very very deadly, deadly gas. It smells bad because it is so deadly to us. We are detecting the tiniest, tiniest [amount]; very few molecules floating around [and] you know it. ...We've come from a very long history of exposure to this stuff in the past mass extinctions. We've evolved to run [from the smell of this gas]. We know just how dangerous this is; our lineage of mammals goes back 300 million years [and] we have repeatedly been gassed by this stuff. We are the survivors of a number of hydrogen sulfide gas attacks. 200 parts per million, 10 times what you can smell, will kill you; and that was the level that appears to have happened at least 12 times in the past 500 million years due to global warming." 

So did we evolve to hate the smell of hydrogen sulfide to keep ourselves safe?

We can smell hydrogen sulfide at very low concentrations. According to OSHA, something in the range of 10 parts per trillion (ppt) to 1.5 parts per billion (ppb) is the beginning of human reception of hydrogen sulfide in the air we breathe (even better than the number that Ward threw out off the top of his head). Somewhere in the range from 2 to 20 ppm is when we start feeling the ill effects of breathing too much hydrogen sulfide, while the hundreds of ppm or more region of hydrogen sulfide exposure can be fatal. 

We know that hydrogen sulfide has had an important role in the evolution of life and the biosphere and may even have been involved in the earliest origins of life on Earth. Sulfur is one of the most important elements for life, but sulfide, it's reduced form, can be quite dangerous for those of us who breath oxygen. The end-Permian mass extinction event, believed to be the greatest mass extinction event in history, occurred about 252 million years ago and may have been highly influenced by the buildup of hydrogen sulfide in the oceans. It's even been suggested that the evolution of multicellular life on Earth, during the Avalon and Cambrian Radiations, was held back for over 1.3 billion years due to hydrogen sulfide concentrations in the middle to lower zones of the oceans. Yet that doesn't mean that we've necessarily evolved to avoid hydrogen sulfide.

Many organisms that would otherwise want to avoid hydrogen sulfide have evolved various mechanisms for dealing with too much of it. I haven't found any literature that can provide direct evidence to support Ward's claim (let me know if you can!), yet it makes a lot of sense as a speculation. Hydrogen sulfide is dangerous to us, so it makes sense that we would have evolved to avoid areas where it's abundant, or even to avoid the gases that are produced from our own bodies since they contain hydrogen sulfide and other reduced sulfur gases. Until I have some more evidence in hand (I'll be reading Ward's book on the Medea Hypothesis soon) I can't say for sure that we evolved to avoid hydrogen sulfide, but that sure sounds like a reasonable suggestion.

Even though the VSCs that make our farts stink only make up <1% of the total gas that comes from our hind ends, that's still a lot more than the range necessary for us to smell it (1%, or 1 part per hundred, is also 10,000 ppm). I don't know if evolution guided us to detest the smell of hydrogen sulfide due to its danger to us, but I can say for sure that the reason our "stink bombs" are so pungent is due to the presence of reduced sulfur gases.

I suppose that leaves one more interesting question about our farts: why are most of us okay (or at least not disgusted) with the smells from our own farts but we always find the flatulence of others to be revolting? 

Well, our detestation to the aroma of the farts of others might not just be due to the sulfur gases contained within but might also be about avoiding potential dangers related to many things that smell bad to us. Here's a video from AsapSCIENCE that considers just this:

You can consider this video a bit further by checking out the review from ThinkTank on Youtube.


Fart Science

If you found this post interesting, then you might want to check out this video by Vsauce on Youtube where he considers some more fart science:

Thunderstruck acoustic by Luca Stricagnoli will blow your mind!

Italian guitarist Luca Stricagnoli

Just came across this amazing acoustic arrangement of AC/DC's Thunderstruck by Luca Stricagnoli. This might just be the best thing you're going to hear today!

Borup Fiord Pass: video from the 2011 expedition to this unique Arctic environment

Science on the ice at Borup Fiord Pass in summer, 2014 (Photo: John Spear)

Borup Fiord Pass is a truly unique and intriguing field site. The deposition of elemental sulfur and microbial processes at the surface of a glacier at Borup Fiord Pass may provide clues we need in our search for life on icy worlds like Jupiter's moon Europa, and strange circular structures in the valley near the glacier may be the remnants of past springs which could inform our future exploration of Mars. I got to travel to Borup Fiord Pass in the summer of 2014 and it was an incredible experience.

My current graduate research is focused on characterizing the materials that form at the surface of this Arctic glacier. Much of that material is rich with sulfur in various chemical forms. I'm now using various instruments to perform my characterizations of the sulfur-rich materials from the site. For instance, I get to use a particle accelerator to conduct x-ray spectroscopy to look at the sulfur!

In 2011, Bob Pappalardo, of the Jet Propulsion Laboratory, and Steve Grasby, of the Geological Survey of Canada, made the trek north to visit Borup Fiord Pass. They took some samples that we've now been using to better understand the geochemical and biological processes that have occurred at the glacier. They also recorded a lot of video. Some of that video was recently edited into B-roll by JPL. The video shows Bob and Steve collecting sulfur on the ice beside a sulfide-rich spring. Take a look and see what you think about the sulfur that forms on the ice at this strange Arctic site:

B-roll: Astrobiology Field Research on Ellesmere Island, Canadian Arctic from JPLraw on Vimeo.

For more information about this strange glacial environment in the Arctic, check out an earlier post on this blog titled "Borup Fiord Pass: An introduction to how an Arctic glacier may aid in our search for life on Jupiter's moon Europa". You can also find articles about Borup Fiord Pass science that have been posted by sites like Space.com and Popular Science.

We'll soon be putting together videos that show our work during the more recent field expedition in 2014. Stay tuned to this blog for those videos and for more of the science and awesomeness of Borup Fiord Pass!

#TDB20, Viking Poetry, and Marooned on Earth as Viewed from Space

Artwork from Storm Thorgerson from Pink Floyd's The Division Bell

Pink Floyd's album The Division Bell was released over two decades ago! 

One of my favorite memories from the mid-1990s was when I spent an entire day listening to this album over-and-over while sitting in an old rocking chair and reading poems from  The Viking Book of Poetry of the English-Speaking World. The skylight windows were open in the attic room where I was reading and a soft summer breeze brought warm drafts of air to where I was sitting. I can still close my eyes and feel the warmth as I rocked back-and-forth and lost myself in a world of poetry and music.

I honestly can't recall anymore how many hundreds of pages of classic poetry I read that day, but the sounds of Floyd and the poetry seemed to flow together into a collage of various thoughts and emotions that hit me in various ways as the hours passed. Ah, youth.

The Division Bell was reissued last year, the 20th year since its original release. For #TBD20, they've also cut a new video for the song Marooned. The song is a chilling instrumental piece that was cut from a few improvised takes onboard David Gilmour's houseboat/recording-studio, the Astoria. The original setting was said to be their feeling of being marooned on an island, but this new video shows something a bit different. 

Starting with views from orbit of our planet, our island in the cosmos, the video then takes us to the now-abandoned Pripyat, Ukraine. Pripyat was abandoned due to the Chernobyl nuclear disaster. On our little island in the cosmos, on our only home, we've built empires and industries, art and science, and yet we've also built disaster and destruction. Your interpretation of the video may be different from mine, especially with regard to the individual performing calculations at the end, but I see it as a story of marooned humanity; this is, to me, a vision of what it would be like if we were to lose our ambitions for a future. Our species is now at a point where we can foresee leaving our little island to explore the greater cosmos, yet, if we don't take care of our island, we could end up feeling less like inhabitants of a beautiful world and more like prisoners marooned in a prison of our own making. 

What do you think?

Only for geniuses? No, finding the answer doesn't mean you're a genius, but these puzzles from Facebook can still be fun

I just came across another one of these puzzles on Facebook the other day. You may already know that I love a good puzzle. Ones like you see here are usually quick and fun. In the puzzle above we have this problem:

111 = 13
112 = 24

113 = 35

114 = 46

115 = 57

117 = ??

In this case, the solution could be 79. But you knew that, right?

These kinds of problems can often have multiple solutions. Some of them are easy and some of them require a bit of work.

The above problem has two little tricks. Firstly, you have to notice the pattern for each operation (the equality symbol in this case does not imply that the left and right are equal, but that there is some operation that can be done to one side to make it equal to the other). To get my answer, the last digit on the left of the equality symbol can be taken as the first digit on the right. The second digit on the right is then the sum of all of the digits on the left. However, the second little trick in this problem is to then skip 116 = 68 and go straight to 117 = 79. Ya, not a big shocker there at all.  Like I said, quick and fun.  

Here are some more of these types of puzzles
(can you figure out answers for all three?):

So, what'd you get for your answers? My answers are, in order:

90, 410, and 143547 (though there are other answers!)

I posted those three problems with an order of increasing difficulty, but they're all still quite manageable since they all follow the same idea as the problem that started this post: namely, assume that the equality sign implies an operation is necessary to form one of the numbers from the other. If you're curious to now how I got my answers to those three problems, then you can cruise down to the bottom of this post. 

Before I get to that, however, I want to point out that answering these questions correctly does not make you a genius, nor should you believe the statistics that claim that only some number of people can get the answer correct.

Only for Geniuses?

Something that really bothers me about these types of puzzles on Facebook is that so many of them say something like "Only for Geniuses" or "Only geniuses will get the answer". What's with that? It may seem a bit silly to think that anyone would feel like they are somehow a certified genius just for answering a very simple problem just because some text on the problem said so, but I wonder how many people really do. How many people out there are swindled by such claims? 

I guess the important question is what exactly is a genius? A quick search online will reveal that there is no well-constrained definition of genius. Dictionaries may give some definition for genius, such as "an exceptional natural capacity of intellect, especially as shown in creative and original work in science, art, music, etc." from Dictionary.com. You might also see definitions claiming that genius implies having a high Intelligence Quotient (IQ). But scoring high marks on a standardized test is probably not the best way to judge. 

It's seems fairly well agreed upon that all people who are recognized as geniuses can score fairly high on tests of logic and reason, but they don't necessarily have to have the highest scores. Richard Feynman, one of the greatest physicists and thinkers of the past century, self-reported that his IQ was only ever measured as high as 125. 

The word genius should be used to imply respect for someone who has shown their mental prowess with mathematics, art, science, creativity, oratory, or teaching, but surely it's not something that can be determined from a simple puzzle on Facebook. That's absurd. Maybe the people who add the "only geniuses" text to those Facebook puzzles are just misled about what "genius" implies, but it's more likely that they're pandering to others in the hopes to increase the "likes" and "shares" of their images. I think the latter seems more likely. Indeed, it's become pretty common for people to use pandering techniques on social media to try to improve their internet presence.

So, what's the point? Why do I care so much? 

I think the "only for geniuses" crap bothers me because I love puzzles, but I don't like having my intellect attacked by pandering. Finding the answers to these puzzles on Facebook doesn't make you a genius, but the people who actually believe that are most likely not geniuses. Even a genius can be suckered into something stupid once in a while, but I think a measure of genius is having the ability to recognize when you're being cajoled.

There's a quote that goes "Everybody is a Genius. But If You Judge a Fish by Its Ability to Climb a Tree, It Will Live Its Whole Life Believing that It is Stupid".  This quote is often misattributed to Albert Einstein though it was likely written in this form first by someone named Matthew Kelly. Is everyone a genius in their own way? I'd like to think so, but the problem with being a genius is that it's only a quality in a person that can be recognized by others. If you want to be a genius, don't worry about what some pandering asshole wrote on a Facebook image, but rather find what you're good at and use that to make the world a better place.

We need a society of people who are literate in statistics

One other crappy thing about some of these Facebook puzzles is when they throw out some ridiculous faux statistic about how few people get these things correct. For instance, the claim that "Only 20% will give right answer on 1st attempt" on the first problem in this post is laughable. Where did they derive such information? Nowhere, of course. They made it up because it sounded impressive and because, once again, they're pandering to people who can be won over through emotional wheedling.

Todd Snider has a song called "Statisticians Blues" where he points out that "...64% of all the world's statistics are made up right there on the spot. 85.4% of people believe them whether they're even accurate statistics or not." Check out that tune here:

What do you think? Are 72% of all statistics really made up right there on the spot? Are you one of the 80.4% who will believe those made up statistics whether they're even accurate statistics or not?

You might have noticed that none of those values matched, and you might have also noticed many times in your life when someone tries to throw some numbers at an opinion to make it sound stronger without having the ability to say where those numbers came from. So what's up with that? 

Statistics is a field of study that focuses on how to qualify and quantify data in a rigorous manner. It's about learning from measurable data and making predictions from known evidence. Statistics is very much a scientific approach to considering data, yet it's constantly misused, especially in our era of data overload.

Misusing statistics is just another form of pandering on these Facebook puzzles, just like the "only for geniuses" claims. These fake stats are an attack on your intellect and your reason, but also on your emotions. Don't fall victim to the wheedling of the people who don't understand statistics! We should all take a little time in our lives to be sure we understand the "writing on the wall"; statistics literacy should be a common goal of all peoples' education in our modern world.

Okay, okay, enough ranting

Here's how I found my answers to those three problems earlier in the post:

How did I get the answers of 90, 410, and 143547?

Let's step through each one and see if you agree with me (again, there are usually many ways to solve these problems, and they often include breaking some of the "rules" of mathematics to do so):

Here's the easy one

This one is very simple. The problem is:

2 = 6 

3 = 12

4 = 20

5 = 30

6 = 42

9 = ??

Just as with the first problem in this post, the idea is to forget what you know of the equality symbol (it doesn't imply equality here, but rather what must be done to the numbers on one side to make them the numbers on the other side). You should hopefully see rather quickly that the operation is to take the number on the left and multiply it by the integer that is one greater than itself (so multiply 2 by 3 to get 6, 3 by 4 to get 12, and so on...). Once you see that you should find that the final answer (??) is 9 multiplied by 10, or 90. 

It's nice to get the right answer, but fun puzzles are definitely not only for geniuses.


Update (13 June 2015): 

Someone left a comment on this post today. They found an answer for this problem of 36, and I love their approach. Here's the comment they left:

f(z) = z * | |z-6| -7|
2 = 6
3 = 12
4 = 20
5 = 30
6 = 42

9 = 36

As you can see, this approach works perfectly well for this problem. Although this one isn't as easy to "see" by looking at the problem, it's still completely valid.

How about this one?

This one takes a little more thought, but it's not terrible. The problem is:

5 + 3 = 28  

9 + 1 = 810

8 + 6 = 214

5 + 4 = 19  

7 + 3 = ???

Remember my answer was 410? Beyond having to think beyond the normal use of an equality symbol, this problem requires you to break your usual thinking of how numbers are arranged. You need to perform some operation to the numbers on the left to make the numbers on the right, but you don't have to follow the normal rules of mathematics and you don't have to consider a string of numbers to be one unique number. What if I told you to think of these numbers like each one is separate? How does this look?

<5> <3> = <2> <8>

Any better? What if I just said "you have to do something with a 5 and a 3 that can give you a 2 and an 8"?

Did you think that the difference of 5 and 3 is 2 and the sum of 5 and 3 is 8? If so, then you're on the right track. 

Applying that thinking to the rest of the problem shows you:

The difference of 9 and 1 is 8 and the sum of 9 and 1 is 10:

9 + 1 = 810

The difference of 8 and 6 is 2 and the sum is 14:

8 + 6 = 214

Following that convention to the unknown gives you, "the difference of 7 and 3 is 4 and the sum of 7 and 3 is 10", hence my answer of 410:

7 + 3 = 410

Don't worry if you didn't get it. That whole "99% People Failed to Solve this Question" malarky is just a bunch of bunk!

Now for the tricky one:

This one may look pretty intimidating, and, admittedly, it took me a couple minutes to figure out.  Here's the problem:

5 + 3 + 2 = 151022

9 + 2 + 4 = 183652

8 + 6 + 3 = 482466

5 + 4 + 5 = 202541

7 + 2 + 5 = ??????

My answer for this problem is 143547. Notice how it has 6 digits? Did you notice how all the other answers have six digits? That's a pretty important feature of this problem.

This is one where you have to look at the numbers available on the left and start trying to figure out the potential associations to single numbers, strings of numbers, and the whole numbers on the right. Doing this, one thing I noticed right away was that the first line has 5, 3, 2 on the left and it has 15 (the product of 5 and 3) as well as 10 (the product of 5 and 2). If you take a look at the rest of the lines, this relationship holds; product of first and third numbers followed by the product of the fist and third numbers. Let's make some notation to explain this.  Let's set a line up as:

A + B + C = xxyyzz

Then, from what I've said so far:

A*B = xx

and

A*C = yy

That just leaves "zz". You may want to think about that one for a moment. Try combinations of A, B, and C using general arithmetic. I'll post the final answer below, but here's a fun cartoon first:

Get more giggles at Explosm.net

Still hanging around? This is a pretty long post, but, if you love puzzles and games as much as I do, then I hope you've found it worth your while. So here's how I found the final answer:

In the first line we get the product of 5 and 3 (15) and the product of 5 and 2 (10) and, if we're looking close, we have 22 yet to figure out, which is pretty close to 25 (the sum of 15 and 10). In fact, 22 is 3 less than 25, which led me to my answer:

For A + B + C = xxyyzz

where A*B = xx

and A*C = yy,

we can find that zz = A*(B+C) - B

or, in other words, zz = xx + yy - B

Now using the numbers from the problem:

7 + 2 + 5 = (7*2) / (7*5) / (7*(2+5) - 2) = 14 / 35 / 47

and, finally:

7 + 2 + 5 = 143547

Finding this answer will not make you a genius and no one has any idea about how many people have successfully solved this problem (or have even run any tests on an adequate sample to statistically say roughly how likely you are to be capable of solving it compared to the general public). Still, if you're like me, then you've probably at least had some fun working on the answers. 

Feel free to comment on these problems, my approach to solving them, or suggest some more fun puzzles!

Borup Fiord Pass: An introduction to how an Arctic glacier may aid in our search for life on Jupiter's moon Europa

Standing on the glacier at Borup Fiord Pass and looking down-valley (Photo: John Spear)

Borup Fiord Pass. I've said that name so many times that it almost feels like the name of a good friend. Last summer I had the opportunity to visit this remote place on the planet, far north of the northernmost cities of North America. The experience was incredible and something that I will cherish forever. My research team and I spent two weeks at Borup Fiord Pass, and when we left we brought back the samples that I'm now studying to better understand the relationships between living organisms and the chemical element sulfur.

Borup Fiord Pass is a valley in the Canadian High Arctic where yellow staining of the surface of a glacier is caused by large deposits of sulfur in its elemental form. This site gives us the opportunity to study the chemical and biological cycling of sulfur through various forms in a unique icy environment. Borup Fiord Pass also gives us a chance to study some of the biological processes we might expect to find on icy worlds with subsurface oceans, such as Jupiter's moon Europa, if life ever came to exist there.  

Europa, one of the most intriguing places in the solar system (NASA)

Watch out where those huskies go...

Borup Fiord Pass is located on Ellesmere Island, very near the North Pole, at the northern extreme of the Canadian territory of Nunavut. To get an idea of where this is, if you hold up a globe and point the North Pole directly toward yourself, then Borup Fiord Pass will be within the first 10 degrees of latitude from the center:

Looking at the world with the North Pole at the center

Benoit Beauchamp, of the University of Calgary, was the first person to see the yellow staining on the glacier at Borup.  At least, that's what I've been told. There are military flights that pass overhead quite often. I wouldn't be too surprised if one of the pilots of a military plane was flying low and happened to see some large yellow patch on the white of the ice. Maybe that pilot thought, "huh, that's interesting." Or maybe some explorer decades ago chanced upon a glacier with a yellow icing that smelled of hydrogen sulfide, but the same explorer didn't see need to note the occurrence. 

We really don't know how long this yellow staining has been happening, though we know it's been active since Benoit first noticed it during a helicopter fly-over in 1988. Once Steve Grasby, a geochemist with the Geological Survey of Canada and my collaborator, learned from Benoit about the yellow coloration on top of the glacier, he knew something special was happening and had to check it out.  

Steve Grasby sampling a sulfur deposit on one his earliest trips to Borup Fiord Pass

Steve Grasby and his earliest collaborators on the Borup Fiord Pass project published the results of their initial findings after multiple visits to the site in an article published in the journal Astrobiology in 2003. In this article they detailed some of the basic characteristics of the yellow sulfur materials and the processes causing their existence on the glacier.  

The sulfur is deposited by springs that emerge on the glacier and which carry high levels of sulfide, the most electron-rich (reduced) form of sulfur, with a formal oxidation state of -2. In considering the chemical composition of the spring fluids and the isotopes of sulfur at the site, Steve Grasby and his colleagues determined that the sulfide is likely derived from sedimentary sulfate deep in the subsurface. Sulfate is the most electron-poor (oxidized) form of sulfur (since the sulfur atom in a sulfate molecule shares it's electrons with four oxygen atoms, giving the sulfur a formal oxidation state of +6). The transition from sulfate to sulfide implies that there must be microorganisms somewhere below the glacier which are using sulfate reduction (making sulfur more electron-rich) for their metabolisms.  

After sulfur in groundwater has been processed by organisms in the subsurface, it then flows up through the glacier or along its base and emerges as springs at the surface. Many years, the springs are still quite active when researchers have arrived to investigate. Last summer, in 2014, there was no apparent spring activity, but rather an earlier spring had deposited a large sheet of sulfide-rich ice. 

Where this icing dropped over the sides of a small canyon, we called the deposit "Sulfur Falls" (see image below). Near the glacier, in the middle of the icing, was a large circular structure that we called "The Blister". This structure may be the remnant of a sulfur-rich plume which had burst its way out from the subsurface and could possibly have formed the icing.

This is me kneeling on a pile of glacial till in front of the toe of the glacier at Borup Fiord Pass.  The yellow coloration of the ice behind me is caused by the deposition of elemental sulfur at this site. (Photo: John Spear)

The sulfide-rich water and ice that forms at the surface then provides the material for the oxidation of sulfide (stripping of electrons from sulfur) to form elemental sulfur (sulfur with a formal oxidation state of 0 and which only forms bonds with other sulfur atoms).  Elemental sulfur forms one of the most beautiful minerals on Earth:

Elemental sulfur: the mineral is yellow in solid state,
turns blood red when melted, and burns a bright blue (Image: Volty)

There are a lot of scientifically intriguing questions that remain with regard to Borup Fiord Pass. For one thing, cells of a certain type of microorganism that our lab has isolated from the field site have the strange capability of forming unique biominerals when grown in gradient cultures of sulfide and oxygen. This was first reported in a paper by Damnhait Gleeson and our colleagues in the journal Geobiology in 2011. We've learned a good deal about these biominerals since that time. Specifically, Julie Cosmidis, a postdoc in our lab, is now working on characterizing these unique structures. I'm also now in the process of looking at the samples from the field to see if any of these unique structures can be found there.

Another interesting question comes from the presence of the yellow sulfur itself.  Given the chemistry of the fluid at the ice surface and the presence of oxygen from the atmosphere, the sulfur should be oxidized the whole way to sulfate, yet the yellow staining persists throughout the summer (at least until the snow begins to fall at this site). Much of my work is now focused on quantifying the different chemical forms of sulfur at Borup Fiord Pass. Expect more posts from me in the near future that details some of the various types of instruments and methods that I'm using in this endeavor.

Using the Field Microsensor Multimeter from Unisense to measure sulfide (Image: Alexis Templeton)

The Connection to Europa

There's been a lot of buzz in the press and social media lately regarding Europa. Europa is one of the four Galilean Moons of Jupiter and is definitely one of the more intriguing places in our solar system for astrobiologists. Europa bears a deep subsurface ocean, and that ocean might have been in recent communication with the surface. If life ever came about in the ocean of Europa, we might have the potential to find signs of such life near the surface of that moon. We're now working on the next spacecraft that will explore Europa.  

Europa's awesome surface textures and deep subsurface ocean are enough to scientifically justify a mission to that moon, but the possibility for life detection in materials at Europa have bolstered scientific and public support together and now it looks like we might soon see a Europa mission on its way to Jupiter. For us to better understand what signs of life we may find on Europa, it's a good idea to study life in icy environments here on Earth. Places like Lake Vostok and Blood Falls in Antarctica and Borup Fiord Pass, my field site, in the Arctic can aide in this type of research. Indeed, Borup Fiord Pass has gotten its fair share of press as a Europa analogue site. Here are articles from Wired, Space.com, Popular Science, and CBC News that report on the importance of Borup Fiord Pass in our search for life on Europa.

With Lake Vostok and other ice-covered Antarctic lakes, as well as some recent research on a drilling project to study the organisms living under the Ross Ice Shelf, we can explore ecosystems in lakes and oceans deep below icy environments. Research in these areas may highlight the techniques we'll need if we ever want to get through the ice on Europa and explore the ocean below.  However, that ice is very thick (probably at least 1 km but maybe more than 10 km in thickness), and it will take us a long time to build a spacecraft with the right technology to get down there. In the meantime, there's a lot that we have to learn about Europa's ocean and the possibility for signs of life to be found in the near-surface of the ice through an orbiter mission and our first lander mission. That's where our work at Borup Fiord Pass comes in. By studying the connection of subsurface microbial processes to the chemical and biology processes that occur where fluids make their way through the ice and to the surface, we might be able to highlight some key signs of life to look for near the Europan surface.  

I was recently at NASA's Ames Research Center for the Workshop on the Potential for Finding Life in a Europa Plume. There are a lot of us who are now trying to figure out what the best instrumentation is to send to Europa to capture signs of life.  You might have read recently about the potential discovery of water plumes coming out of Europa.  Although some of us are highly skeptical of the data in that study, if there are water plumes at Europa, they may offer even more insight into the processes that are occurring in the subsurface ocean.  Even if the plumes are not there, we still have a lot to learn with the mission that we'll be sending to Europa. If we can get data about the chemistry of the surface or, better yet, the near subsurface, then we may be able to find signs of life from the subsurface ocean.  This of course requires that fluid from the ocean has made its way through the ice and to the near surface. There's a lot of "ifs" involved, but that's part of the fun of science.

In the coming months, I'll be writing up posts that detail the importance of sulfur for astrobiology as well as the importance of Borup Fiord Pass in our exploration of Europa (and other worlds). These are important topics for me, especially since they'll be included in my Ph.D. dissertation.  Before I leave you, though, here's a sweet infographic from NASA regarding Europa, one of the most intriguing worlds in our solar system:

Senator Jim Inhofe needs better glasses: A snowball cannot refute climate science

Sen. Jim Inhofe and his poor vision (ABC News)

Senator Jim Inhofe needs better glasses.  It appears that he's having a hard time seeing past his own nose.

In an attempt to refute climate science, Inhofe took a snowball out of a bag while speaking on the Senate floor on the 26th of February, 2015, and said, "I ask the chair, you know what this is? It’s a snowball, just from outside here. So it’s very, very cold out."  Inhofe appears to be suggesting that the occurrence of snow this winter in Washington D.C. negates the wealth of evidence and scientific understanding about the human influence on global climate.  It really seems that, if anything, Inhofe's stunt is just another reason to shake our heads at the lack of vision amongst some of our politicians.

This isn't the first time that Inhofe has tried to make some statement regarding his belief that scientists have fabricated anthropogenic impacts on the global climate.  Back in 2010, Inhofe and his family built a snow fort on the lawn of the National Mall in a mockery of climate science.  They called this snow fort "Al Gore's New Home".  In fact, Inhofe has been making such statements and attempted jabs throughout his political career.  Inhofe has been the Chair for the Senate Committee on Environment and Public Works since 2003.  It's somewhat bewildering to think that someone who honestly believes a snowball can refute all of modern climate science can also hold the highest rank within a Senate committee which requires knowledge of the environment.  Here's a video of Bill Maher from back in 2009 where he considers climate change deniers, including Inhofe:

Maher's bashing of Inhofe is more than warranted.  To better understand the Anthropocene and the impacts of industrialization and human activities on the environment we must have scientifically literate world leaders.  Infrastructure development, coastal economies, weather-related dangers and costs, growing seasons and crop yields, and far more will all be impacted by the global climate.  Politicians like Inhofe are a threat to the future of our species and to our biosphere.  We need leaders who can see that there is more to the world than their own day-to-day experiences.

Senator Sheldon Whitehouse: A leader with greater vision

At least not everyone on the Senate Committee for Environment and Public Works has poor vision.  Senator Sheldon Whitehouse, a politician from Rhode Island, took the Senate floor to rebut Inhofe's remarks later in that same day.  Senator Whitehouse has given many speeches on the Senate floor in support of science literacy and education with regard to the current and future effects of anthropogenic climate change.

Senator Sheldon Whitehouse (Image: Stephen Crowley/NY Times)

Senator Whitehouse took out his iPad and brought up an image from the Earth-Now app, a free application developed by NASA to share global climate data with anyone and everyone (you can use this app to see where several of our Earth observing satellites are in their orbits and to map various physicochemical parameters such as air temperature, CO, CO2, sea surface salinity, and ozone).  Whitehouse points out that you can use this app to see the current polar vortex in the Arctic and how the cold air is being driven down to New England.  Whitehouse, highlighting the fact that these basic climate data are available from NASA, then said, "...you can believe NASA and you can believe what their satellites measure on the planet, or you can believe the Senator with the snowball."  

Indeed, Senator Whitehouse then points out four more instances in which one can side with a group or organization which supports the wealth of information from climate science or one can side with "the Senator with the snowball".  Although I usually oppose this pitting of side-vs-side on political issues (most issues are more complex than yes-or-no or red-and-blue), Senator Whitehouse is definitely a skilled speaker and gives a strong argument in support of scientific literacy from more than just the scientific viewpoint.  Here is Whitehouse's rebuttal:



Take home point from Whitehouse's rebuttal: you simply can't be scientifically literate if you agree with the Senator with the snowball.  The occurrence of snow on a winter day in Washington D.C. does not refute our knowledge of the changing climate.  2014 is now the hottest year on record, with higher average global temperatures than any previously recorded since the 1800s.  We still have the seasons and we're still going to experience hot summers and cold winters, but the general trend of warming at the global scale is still occurring.  It's hopeful to think that we at least have some politicians, like Senator Sheldon Whitehouse, who support a scientifically literate populace and leadership with greater vision.

Frosty the Snowman has no idea about climate science

Let's face it, Frosty the Snowman was only imbued with knowledge about winter.  Still, in his various incarnations, Frosty has always known well enough to take off before the warming temperatures destroyed him because that's how the seasons work in the regions of our planet that get snow in the winter.  

We can learn a lot from the snow.  We can measure the pH of the water composing the snow and can study the particles of dust and debris mixed into the snow to learn about the chemistry of the clouds and the atmosphere where that snow formed.  However, a snowball, in and of itself, is not a refutation of modern science, science literacy, or our combined knowledge of the human impacts to the global climate.

There's plenty of snow here in Boulder, Colorado, U.S.A. right now.  Maybe I'll go outside and make a snowball, without any pretensions that the weather in my backyard means that everywhere else is the same.  If you'd like a good laugh, here is some climate science denier busting by John Oliver of Last Week Tonight:




You can find 5 hilarious moments of climate denial busting, including the videos from Bill Maher and John Oliver that I posted in this blog, from Forecast the Facts at this link.



Update: 3 March 2015

Looks like I beat the Daily Show to pointing out the ridiculousness of Jim Inhofe's little snowball stunt:

I've been through the desert on a horse with no name, which then carried me from the Sahara to the Amazon

Image: NASA Goddard Space Flight Center's Scientific Visualization Studio

There's a lot we can learn from Earth observing satellites.  For instance, the dust from the Sahara desert, the world's largest desert, has been found to travel through the atmosphere, making its way across the ocean and settling down to fertilize the Amazon rainforest.  That's quite a journey, and it probably seems a bit baffling to think that the material from a desert can then help to sustain all the diverse organisms that live in the world's largest rainforest.

A team of researchers have recently provided estimates of the amount of dust that makes the journey to the Amazon.  Of the 182 million tons of dust that gets lofted out of Africa, some 27.7 million tons of that same dust then finds its way to the Amazon rainforest.  The same team of researchers that made this discovery have also announced that the phosphorous within the Saharan dust fertilizes the rainforest.  Some 22,000 tons of phosphorous are estimated to rain down to the Amazon, far from their Saharan origin.  The researchers estimate that this influx of phosphorous makes up for the all the phosphorous lost to erosion.  Our world is truly dynamic.  Our fleet of Earth observing satellites have so much to teach us about our home.

Here is a fantastic video from NASA explaining these new discoveries:

For more information about this research, check out the NASA Press Release.