The Aquarius Project 2: Into the Deep Void

by Shane L. Larson

When you stand on the shores of Lake Michigan, you cannot see the far shore. Many days of the year, the surf is a gentle lapping over stones or against breakwaters, but there are definitely days when weather whips the water into a frenzy, tossing up waves worthy of ocean waves. You can’t help but notice it is big water. 

Lake Michigan is the second largest of the Great Lakes, covering an area of 58,000 square kilometers and harboring 4918 cubic kilometers of water. In the early morning hours of 6 Feb 2017, a hunk of debris from outer space hurtled into Earth’s atmosphere, somewhere in the skies slightly to the west of Kewaskum, Wisconsin. Leaving a glittering trail of burning dust and shining brightly enough to cast shadows across the dark winter landscape of the Midwest, this space rock broke up and the fragments rained down about 10 miles off-shore in Lake Michigan, near Sheboygan, Wisconsin. Despite happening at roughly 1:30am, 511 people across the midwest reported seeing it. All those reports, together with a few others we had heard, let us make a good guess where it might have fallen in the Lake.

Here “we” are myself and colleagues from the Adler Planetarium, the Field Museum, and the Shedd Aquarium. “We” are a few professional scientists and (sorta) grown-ups, and a remarkable group of young people from the Adler, called “The Adler Teens.”  In the grandest tradition of scientific adventures, we decided it might be fun to go look for fragments of this space rock. On the bottom of Lake Michigan.

Our expedition would be aboard the Neeskay, a research vessel belonging to the University of Wisconsin-Milwaukee.

Scouring the bottom of Lake Michigan for a fallen space rock sounds like fun, but why would we do such a thing?  The answer begins far above our heads, in the inky dark between the planets. The solar system formed from a vast cloud of stuff that eventually accumulated into the planets and other bodies in the solar system. Just like when you clean your house, you don’t get every little fleck of detritus there is — there is always a little bit left over. The solar system is no different — there are bits of stuff floating around everywhere. You may remember from your ponderings of the night sky that there is a lot of such material between the orbits of Mars and Jupiter, called the asteroid belt. There is an additional vast swarm of stuff surrounding the solar system called the Oort Cloud that is the origin of most of the comets we see.

But randomly drifting around there is also other stuff; when space rocks are in space they are called meteoroids. They are interesting because they hold a set of stories, about the early history of the solar system if they are left-overs, and about the historical nature of the other planets and moons if they are fragments blasted off of their surfaces in collisions.  If by chance, one of them should tumble into the Earth’s atmosphere, the tremendous speeds generate tremendous heat and the meteoroid becomes a meteor, a glowing coal of stuff that briefly illuminates the night sky. You and I call these things “shooting stars,” and if they are spectacularly bright, we call them “fireballs.” Finally, if one of these meteors should make it to the surface of the Earth, where it can be picked up and handled and oogled and tested, we call it a meteorite. Meteorites harbour the same stories they did when they were meteoroids, they are just much easier to get your hands on. IF you can find them.

Our sled, on the desk of the Neeskay, waiting to be launched.

So we made a plan to survey the bottom of the Lake looking for this meteorite. While the original concept had been to simply dive down with an amateur ROV (“remotely operated vehicle”), like one from OpenROV, or designing our own, the team rapidly came to the realization that we wanted to keep anything we found and bring it to the surface. A cool idea, but a challenging one at the same time.

As is often the case in science, having a cool idea means you also have multiple competing problems that must be solved. For the Aquarius team, the competing problems were this: how do you cover a vast, VAST area of the lake bottom, find everything that looks interesting, and get it all to the surface. Working your way through such a list of problems is exactly what science is, and it is an iterative process. You imagine a solution, you tinker with it, you build prototypes, and you test them. When the prototypes don’t quite work, or fail dramatically, or succeed in unexpected ways, you take what you have learned and modify or build a new version, and start the testing all over again. Eventually, your efforts stabilize and coalesce around a final product — a plan, an experiment, a workable design. For Team Aquarius that design was a sled we call RV Starfall.

The sled is a scientific device in the grandest tradition. If you just walked up to the sled not knowing what was, then the most apt description of it you might come up with is contraption. A contraption it is. Overall, it is about 1.4 meters long, about 1.2 meters wide, and about 25 centimeters tall. Its made of plastics and metal, with bolts and cables holding it together.  The superstructure of the sled is laid out by four vertical slats that define the shape. The slats are held together by cross-members that provide strength and rigidity. There are two sled-rails on the bottom, bent upward at the front, to help the sled glide over the underwater landscape, no matter what it might encounter (just like the rails on a winter sled or snowmobile). 

A computer model of the sled, viewed from the rear. Note the clear sample capture bins near the front, the curved edge of the sled runner on the bottom, the three magnet wheels across the middle, and the wire capture cages on the back. The red “bricks” on the slats are also magnets. [Model by Annelise Goldman]

Attached at various points on the sled are different devices that were designed to find and recover samples and interesting objects (“possible meteorite candidates”) from the bottom of the lake. The strategy that guided the sled design was passive collection without inspection — pick up everything that is potentially interesting, and bring it back to the surface for later classification and analysis. Look at the back of the sled. There you’ll see three mesh footballs — if they hit something like a small rock (or meteorite!) as they get dragged across the lake bottom, the tines of the mesh spread open and the forward motion of the sled pushes the rock inside, then the mess closes behind it effectively trapping it. A brilliant mousetrap for a meteorite!  There are also magnets all over the sled, strategically positioned to attract metallic fragments and hold onto them until the sled reaches the surface again.

The most active group of magnets are on the three wheels in between the vertical slats. As the sled gets dragged across the lake bottom, the wheels rotate and attach to any metallic fragments they encounter. As a wheel rotates up and over, it encounters a “scraper” that pries off any large bits and drops them into three catch pods (clear acrylic) between the slats. The idea here is that something large might attach itself to a magnet, but if you don’t pry it off and save it, something might later knock if off and you’ll never know you had it. On the bottom of the sled, there are some V-shaped brushes that guide material toward the magnet wheels, as well as a variety of other magnets attached on open surfaces to catch any “just in case” bits the sled might encounter. 

Last but not least, there is an attachment bracket on the front of the sled, where we could mount a video camera to send live pictures of the bottom of the lake back to the surface. The sled is attached to a cable, which is lowered by a crane into the water to the lake bottom. A video cable attached to the camera is clipped to the cable as it is extended, delivering live movie data back to the team in the control room (“Mission Operations Center”) on the Neeskay.

A maritime navigation map of Lake Michigan, east of Manitowoc, with Chris Bresky indicating where we are heading for the sled drops.

We had a boat, we had a meteorite recovery sled, but where do we go? Despite the immense size of the lake, we had a good idea where the meteorite fell from all the reported sightings and the signature on weather radar the morning of the event. Several of the meteorite experts on our team had used codes that they had written as part of their professional research to model the breakup of the asteroid, predict the sizes of fragments, and then simulate how those fragments would fly through the atmosphere and into the water. Those analyses produced a map of the most likely areas to find meteorite fragments of different sizes. One of our meteorite colleagues on the expedition with us, Dr. Philip Willink, took those maps and predictions and estimated the average separation between meteorite fragments on the lake bottom. He estimated that in the areas dominated by 1 to 5 gram pieces (about the size of a marble) we would have to drag the sled about 1.5 kilometers across the lake bottom to encounter 2 fragments. The lake is big, and those aren’t very good odds. But it’s also not impossible!

Phil’s roughed out calculation of how far we’d have to drag the sled to find a piece of the meteorite.

I tried on the survival gear during the safety briefing!

Using Phil’s prediction, we decided to do several mile long drags of the sled (“transects” across the fall field). With that in mind, there was nothing left to do except go out and start searching. The anticipation was palpable — this was literally what we had been waiting more than a year for, planning and imagining.

Scouring the lake depths for fallen space rocks is an all day affair. We arrived bright and early to our expeditionary vessel, the Neeskay. We had a safety briefing from our captain, tried on some of the survival gear, and we set sail. Our destination was off-shore about 16 kilometers, in about 70 meters of water. The Great Lakes are temperamental — soggy days and blustery weather can whip the Lake into a frenzy. But on this day we were lucky — the skies were clear, the winds were gentle, and the Lake was calm.

We loaded all our gear on board, we stowed the sled on the rear launch deck, and before we knew it, Neeskay turned in the harbor, and pointed her bow to the southeast. We were off. The moment we left the harbor was striking to me. Being a kid from a land-locked state, the view off the bow was one of completely open water, with not a speck of land in sight. If I didn’t turn around and look back the way we had come, it could have just been the endless blue expanse of the open sea.

[LEFT] Our expedition leader, Chris Bresky, lays out our plan for the day. [RIGHT] A map of our target area, showing the predicted density of meteorite fragments of a given size on the lake bottom, worked out using a computer model. The blue dashed line near the bottom of the oval shows our first drag, and the purple dashed line shows our second drag.

It was about an hour to our first drop point. On the journey out, we had a briefing about the target area and the drag plan. We would do two mile-ish long transects, one NE to SW, and one N to S. After the first transect, we’d pull the sled up, clean it off and store recovered samples, then drop it for the second run.

[LEFT] The sled is lowered into the water using a hefty steel cable being spooled off of a crane. ][RIGHT] As we let out cable and the sled descends to the lake floor, we clip the cable to our video feed that is bringing live images back to the surface.

When we arrived on site, we attached the sled to a tow harness, we bolted our video camera onto the nose, and we hoisted it up until it hung vertically over the deck. Pivoting it out over the edge of the boat, it hung poised over the water, just waiting for a moment, then cable began to unreel, it slipped beneath the waves, and was gone. The video feed was carried along its own cable. We didn’t want it to get tangled up on something, so every couple of meters we paused and  clipped it to the main tow cable to keep them together.

Pretty much the entire time the sled was in the water, the team huddled around a couple of computer monitors, watching the live video feed, and discussing what we might be seeing, noting down interesting time markers to go back and watch more closely. These were the moments we had been waiting for — having our experiment work successfully, and showing us something that had never been observed before.

In the operations center, the team could watch the video feed as the sled descended into the depths. At first, the image was a brilliant cerulean green, but as the sled descended, less and less sunlight from the surface was making it to the depths, and the images got darker and darker. The meager light from the camera lights revealed only a monochrome murkiness, and the faint shadow of our cable stretching out into the darkness above, where the team waited aboard the Neeskay.  And then….

Live video touchdown image from the bottom of Lake Michigan, 70 meters beneath the Neeskay.

Touchdown! The sled settled onto the bottom of the Lake, churning up a cloud of silt and dirt when it landed, not unlike the landers on the Moon. We had arrived!

As is often the case in science, we discovered something new and interesting immediately. Based on previous surveys of the Lake from two to three decades ago, the depths we were at had very little in the way of a visible macroscopic biosystem — a few lake creatures and fish, but by and large the temperature and light at these depths meant the lake bottom was a bare, open, abyssal plain. But that was not what we were greeted with on the monitors. In every direction, as far as our cameras could see, the lake bottom was covered in colonies of quagga mussels.

The lakescape we could see, as far as we could see in every direction, was dominated by quagga mussels. A few bare spots existed, but they were few and far between.

Quagga mussels, like their cousins the zebra mussels, are an invasive species in the Great Lakes, having been transplanted in the ballast water of ships that plied both the Great Lakes and other waters in the world. Over the past few decades they have been spreading through the Lakes, starting in large colonies in shallow waters, but clearly now also extending into the deeper waters. There are lots of interesting questions that immediately spring to mind. For instance: As we moved across the lake bottom, there are small patches here and there where the mussels hadn’t settled — what were those? Are the mussels not there yet, were they cleared away somehow, or is there something different about those patches? How far into the depths do the colonies extend? Are the depths they are reaching simply growing with time, or correlated with other environmental aspects of the lake (like temperature, lake currents, water chemistry, or other suspensions in the water)? Those are questions for another day, and a future expedition and a future team. As dutiful observers of Nature, we record our findings and the conditions under which we made them, together with thoughts we have, and report them to our scientific colleagues for further consideration.

Once we were on the bottom, we started our run. The captain revved up the Neeskay and we started trundling along our planned transect at about 1 knot (1 nautical mile per hour, which is about 1.15 mph = 1.85 km per hour). But as you might guess, it’s not that easy! We wanted the sled to glide over the bottom in contact with the surface. If we were going too fast, the sled started to “fly” from the hydrodynamic forces of the water lifting it like it was an airplane. We knew when we were on the bottom because we would see occasional puffs of silt and dirt, like the cloud we saw when we landed. If we were going too fast and flying, then we never saw any puffs and the mussels were really flying past fast. 🙂  The video below shows about 2 minutes of what flying over the area was like, extracted from the Aquarius video feed.

So for about an hour, all we could do was watch the video screen, occasionally talking with the captain about speeding up or slowing down by a smidgen. The mussels sailed by — endless lakescapes of mussels. Surprisingly, there were often apparent detritus from our civilization that we could see — bars of metal protruding from the lake bottom or other bits of shattered something. In many ways it was surprising, because you have this sense that the lake is vast and there is no possible way that humans could have somehow made their imprint on so much of it that a random trip across the bottom would turn up some artifacts from our civilization. But we have. It is a testament to how much time humans spend on the lake, and how far reaching our influence likely is.

Two examples of interestings “things” that passed with the field of view of the Aquarius sled camera. Possibly natural (wood?) and possibly anthropogenic (metal?). The team noted where they were, in case we ever want to go back and look at them too.

Eventually, we decided to haul the sled up, clean it off, and preserve any samples we found. The ascent was a little slower than the descent because as we hauled it up, we had to separate the video cable and the tow cable. Separating the two was not nearly as straightforward as clipping them together — while the sled is in the water and the cable is under tension, the two cables wind around each other, so as they come out of the water and are separated, all of the twists remain in place! The result is a giant spaghetti ball of cable that you have to manage as the sled ascends. It’s only 70 to 100 meters of spaghetti cable, but it’s a plenty big mess! If you’re watching on the monitor, eventually the sled video can see us up through the water as it ascends, a distorted fun house view of the team, peering eagerly into the water to see what secrets had been pulled up from the depths.

[TOP ROW] As we raise the sled, we have to cut the video cable free from the tow line, but it turns into a big spaghetti mess that must be managed as the sled returns home. When it is near the surface, it can see the mess above it! [LOWER ROW] When the sled is clear of the water, it drops all kinds of mud that it has been dragged through. We have to grab the sled, and pivot it back onto the deck so we can begin cleaning it.

As the sled emerges from the water, there is a flood of mud that is released as water sheets off of it, but we move it aboard and finally it is laid down on the deck. What happens next is a burst of activity: every member of the team moving to do something to get us ready for the next transect. The captain turns the boat and heads to our next drop point. A group grabs the spaghetti ball and takes over an entire side of the Neeskay to untangle it and lay it out, untangled, for the next drop. A cadre of people with cameras and smartphones are taking pictures of everything, documenting what is going on. And the sled itself is surrounded by a pack of the Aquarius team, shoulder to shoulder, digging in to clean the sled and preserve the recovered samples.

[LEFT] The moment the sled was on the deck, the Aquarius Team was swarming all over it. No known force in the Universe could have kept them away. [RIGHT] Getting the mud off was a chore; spraying it off worked well, but then the mud had to be gathered off the deck and sifted through.

The philosophy of the sled clean-off stage is simple: keep everything for later. Set aside interesting stuff for careful consideration later.

There is a lot of mud. Some of it we spray off, carefully sifting through it for anything that was surrounded by the gooey stuff. The cleaning teams grabs great gobs of the stuff and mashes their hands through every little bit of it, looking for anything small and solid. We find rocks, we find clear bits of metallic somethings. We keep it all, and toss it in big 5 gallon buckets. The buckets are marked with the day of the expedition, and the transect that we made, so when we get back to the lab we’ll know where the samples came from. We find stuff stuck to the magnets — all the magnets — so we pull it off, and stick it in the buckets. Every now and then we find a mussel; what do you do with that? You see if it sticks to a magnet! If it sticks, you keep it — it probably has eaten something metallic (possibly a meteorite fragment) and we want to know what it is! If it doesn’t stick, we toss it back into the Lake. If something looks particularly interesting, we show it to one of our meteorite experts, who decide to toss it in the general buckets, or keep it in a special “oooo interesting” container. 

[TOP ROW] The magnets collected plenty of material. Notice the fine grain black stuff — this is “magnetic mud,” the kind of stuff you can pick up in a sandbox with a magnet, comprised largely of metallic rich grains. [LOWER ROW] We mash through ever little bit of mud with our hands, looking for fragments and interesting bits. With the mud cleared away, there are a variety of different things we find, almost all of which we keep.

The entire clean-up takes 30 to 60 minutes, and by the time we’re done, the spaghetti cable is untangled, and we’re ready to make a second drop. We hook RV Starfall back onto its cable, pivot out over the water, and drop it in for a new run. Wash, rinse, repeat!

Really interesting looking samples are set aside, to make sure we look at them more closely later, and to insure that we don’t lose them in all the detritus.

But all too soon,  you discover the day has wiled itself away. The Sun is heading toward the horizon, you have buckets of samples, thousands of pictures, hard drives full of video, and notes, thoughts, and observations from everyone on the team that need to be collected, collated, read over, pondered, and speculated with. 

With the happy melancholia that accompanies the end of any adventure, the team looks to shore as the captain turns the bow of the Neeskay to the west, and we begin to steam toward home.

Now, the samples are back in the lab, and the next long bit of hard work is happening — consulting with scientific colleagues who are experts in meteorite identification, and figuring out what all this stuff is!

Now, our samples are in the lab. Fall is winding away and winter will be here soon. This is the time for careful lab work and analysis of all the samples we’ve found. There are, perhaps, fragments of our meteorite in the collection. If there are, we will be beyond excited. But if there are not, the samples still represent a treasure trove of knowledge about one small part of Lake Michigan. Contained in those carefully preserved samples is a story, yet to be understood, about the geology and history of human influence in that part of the Lake. We’re going to find out what we can learn from that hard earned haul — truly a treasure, valued in the sweat and joy and mystery of its recovery.

———————-

This post is the second of two describing my adventures with the Adler Planetarium’s AQUARIUS team. The first post was here: https://wp.me/p19G0g-LB

You may also enjoy listening to the Adler Planetarium’s podcast series about Aquarius, it is excellent. You can hear them online here:  https://www.adlerplanetarium.org/education/far-horizons/aquarius-project-podcast/ 

The Aquarius Project 1: The Cosmos Beneath the Waves

by Shane L. Larson

The wind is brisker, the nights cooler and crisper, and something about the slanting misted light of morning says autumn is here. Over your morning nibbles, with your family prattling around you in the kitchen and the hum of a weekend just getting underway, you look back through your memories on social media, and it’s like “Wow! I had some awesome adventures this summer!”

During the daily grind, when the morning commute is doing its best to wear down the gears of your soul, and the daily maintenance of jobs and life stretches well beyond the length of a reasonable ToDo list, I sometimes despair that there are no great adventures to be had. But those are just little demons whispering, preying on weariness. In reality, I think there are always new adventures launching without you even knowing it. Some of them lead to great friendships and growth for your community around you. Some of them bring great good to the world, even if it is just a small group of people around you. A few indelibly ink a memory in your heart and soul that you will carry around with you to the end of your days in this Cosmos. This is an adventure story with all of these. Like most adventures, it arrived unexpectedly, and grew from humble beginnings. It started one winter night in the northwest suburbs of Chicago.

I’m a bit of a short sleeper, so I’m always up late at night, long after the rest of my family and friends are slumbering. It’s always quiet, just me and the cats. When it’s nice, I can do a bit of backyard astronomy, but if the weather is inclement, I can wheedle away hours in the workshop or at the Lego table.  More often than not, I have papers from my students to read, or lectures to write, or homework to grade. The latter was the case in the early morning hours of 6 February 2017. My study is on the second floor of our house, and I have my writing desk situated to look out over the wetlands north of our home. 

I don’t recall exactly what I was doing, but I was up and at my desk. At 1:25am I just happened to be looking north and witnessed one of the awesome transient events you can see in the sky, a fireball. I’m an active amateur astronomer (I’m also a professional astronomer, but that’s a discussion for another day), so I’ve literally spent thousands of hours out under the night sky. I’ve seen fireballs before, but they are not common enough to simply shrug your shoulders when one graces the skies overhead. They are all of them dramatic, bright, beautiful, colorful, and awesome to behold. This one was no different. It had a brilliant teal colored head and a streaky tail that was long and “sparky” with a yellowish color. It was BRIGHT. So bright that it lit up the walls inside the house and cast shadows, like a long duration flash bulb had gone off.

I’m one of those amateur astronomers who has a strong habit of writing everything down when it happens; if you have a birder friend who keeps a lifelist of all the birds they’ve seen, I’m of the group of amateur astronomers who do the same thing only with objects in the night sky.  I try and immediately write down everything interesting I see happening in the sky. I note everything I can — the time, how “big” it looked in the sky, how long it lasted, and anything I noticed like its color or shape or behaviour. All those details are important to write down in the moment before your brain thinks about it and embellishes it. Colors are completely subjective, but for an event like this, they are the best description you can usually give. The size is also not precise, but you can use old astronomer tricks to estimate the size of an object, either by referencing other things you can see in the sky (like the positions of stars) or using your hands. In this case, the fireball was perfectly framed in my window, so I used my hands to estimate angles. I also like to simply write down my responses — from my journal entry above, you can see I was pretty excited.

When you need to quickly estimate angles in the night sky, use your outstretched hands. The width of your fist is about 10 degrees, and your spread hand is about 20 degrees fingertip to thumbtip. [Image: S. Larson]

It is all well and good to keep your own notes about what you see, your personal dialogue of your relationship with the sky, but if no one ever hears about what you saw in the sky we can’t use your experiences to learn more about the Universe and our place in it. There is something special in the sharing of communal experiences with the Cosmos, and sometimes we can learn something new at the same time. When that fireball lit up the night that winter morning, I did two things. The first was to ping all of my local friends on email and social media, on the off chance someone had also seen it. The second was to report the event to the American Meteor Society, which collects observations and collates them together. 

My initial query to my friends to see if any of them saw the event.

In the end, hundreds of people all over Illinois, Wisconsin, Michigan and Indiana reported the event, and collating all of our reports generated a good guess about what the fireball did, pointing to something I had speculated: it probably came down in Lake Michigan. You can see the report at the AMS online here.

The American Meteor Society map showing people in northern Illinois and southern Wisconsin who saw the fireball. Reports came in from a much larger area than this, but in this view you can see the estimate of the meteorite’s trajectory (between the green and red pins). [Image: American Meteor Society]

My email to my friends and colleagues at the Adler Planetarium ended up being the seed for this particular adventure story. One of my hobbies is constructing underwater robots (ROVs — remotely operated vehicles), which is also another story for another day. But in my email, I speculated on whether or not we could use such a “hobby” to perhaps dive down to the floor of Lake Michigan and take a look around on the off chance that we might find something.

The early email, speculating that maybe an ROV could be used to look for any possible fragments from the meteorite.

Now why would we do that? Material from outer space rains down on the Earth all the time. On any given night, if you spend enough time looking up, you’ll see numerous quick streaks of light slashing across the sky — the “shooting stars” you learned about when you were young. Most of these are small, no bigger than a grain of sand, and burn up in the atmosphere high above you, leaving only the flash of light and your memory of its existence. Throughout the year, we have regular “meteor showers” when the Earth sails through the trail of dust and debris left behind by comets as they blaze their journey toward the Sun, dropping fragments of ice and dust that we see as their tails. Such events are not unique to Earth — they also happen on other worlds (one of my first scientific papers was about using comet orbits to predict when you might see meteor showers if you lived on other planets in the solar system). Larger fragments of stuff also hit the Earth, though less frequently, with fewer and fewer instances as the size gets larger and larger. Things the size of baseballs and laundry baskets will light up the night sky and while they can cause damage, aren’t devastating. Most events of this size are over the ocean and out of sight of stargazing humans because 71% of the Earth is covered by water!

A typical shooting star (this one is a meteor during the Perseid Meteor Shower). [Image: S. Larson]

NASA estimates that around 100 tons of material hits the Earth every single day. But most of that is small flecks that vanish in a sparkling flash of light, sometimes seen by someone like you looking up from their backyard. But a few pieces — a precious few — make it all the way down. Something about the size of your fist has a good chance of making it to the ground. Meteorites are not as common as everyday rocks, but not so rare that ordinary people like you and I can own small fragments purchased in museum gift shops or from reputable dealers.  Never-the-less, they are rare enough to still be of intense scientific interest. After tracking this random fireball through the skies of the Midwest it seemed, perhaps, we knew where one had come down in Lake Michigan, and maybe a little adventure was in order.

Me and the indomitable Chris Bresky, off on an adventure.

The adventure started innocently enough, because my Adler colleague, Chris Bresky, thought pitching ROVs into Lake Michigan to look for sunken space rocks not only sounded cool, but would be a great way to engage area teens in some science investigation. It has all the hallmarks of what science is all about. It begins with a phase of Big Thinking, where there are no boundaries. You put a group of interested people together in a room or on an email thread, and you just talk. The rules are simple: no idea is too whacky, no question is too silly, everything should be put out there for discussion. During the Big Thinking phase there are no limits or considerations of limits, there is no quarter given to practicality or logic, there is no worry about regulations or costs or anything. That is all for later. In the beginning, you want to let your imagination run wild, and let your curiosity and excitement drive what you are thinking and talking about. Why? Because good ideas come from unfettered imaginative thinking. There are many ideas and hypotheses that are untenable or wrong. There’s nothing wrong with exploring those ideas — that is the pathway to finding out what is possible and what is true. When we are first embarking on a journey of scientific investigation, we do not know where fundamental insights will come from, or what will spark them. 

It’s not that all the squirrel-brained ideas that come out of the Big Thinking phase are workable or even reasonable. That’s not the point of Big Thinking. The point of Big Thinking is to have conversations about the ideas that form around all the squirrel-brained ideas. For this project, we started with simply the idea of an ROV to photograph whether there was a piece of this space rock on the bottom of Lake Michigan. That simple question opened up a remarkable spectrum of questions that would ultimately be an important part of our adventure.

Big Thinking started early, even in email. Chris’ imagination was captured early on.

What was the bottom of Lake Michigan like? Probably rock and dirt, as the depths in the target zone are too deep for sunlight to penetrate and support plant life.  Is it mud or hard packed surface? If it’s mud, will we see little divots from meteorites or will they sink in the mud? If it is hard packed will the meteorite sitting on the surface just look like another rock? What is the Lake really like in the area where the fall happened? No one really knows, because 99% of the Lake hasn’t been seen, only surveyed by sonar and most of that at low resolution. Do we just want to take pictures? What if there is a big rock we want to recover? Can we make a robot arm to pick it up? Will we need to dig on the bottom of the Lake? Can an ROV even lift a giant space rock?

And so on. Over time, we coalesce together into a team, and we develop some common language and ideas, and a plan begins to emerge. In this case:

• we didn’t even know where there was a space rock, only a huge area that it could be in. If we were going to search, we had to be able to search vast areas.
• we absolutely wanted to recover some space rocks if they were on the bottom of the lake. Anything was probably small, so we’d have to recover material and separate it on the surface
• like outer space, the bottom of the lake is not amenable to humans hanging out, so we’d have to do this space-exploration style — with uncrewed, mechanical entities
• we’ve never done ANY of this before; few if any people have looked for space rocks in deep water before. So we’re going to have to figure out how to do it, teach ourselves, learn from our mistakes, and then execute our search on the true frontier — the unexplored depths of Lake Michigan.

After that, it’s time to start rolling. You get your hands dirty and your feet wet and you make your brain tired, for months. Not exhausted tired; happy tired. So tired you can’t fall asleep at night because you’re still turning a problem over in your head tired. The core team in this endeavour are a group of kids from Chicago we call “the Adler Teens” (follow them on Twitter, and Instagram). Like all teens, they are extraordinary. They’re excited, they’re passionate, they’re full of boundless energy, and they want to learn how to solve cool problems. There are also a few of us grown-ups around too, but we try to stand back and let the team push the project forward. The beauty of science is there are as many ways to solve a problem as there are people trying to solve them. Some solutions work better than others, but no solution is right and no solution is wrong. I’ve been a science educator my entire career, and while I could go and figure out a way to find and recover space rocks on the bottom of Lake Michigan, I long ago learned that some of the most inventive solutions to problems come from students who are learning to flex their scientific skills.

Doing science requires talented minds with all kinds of skills. The AQUARIUS Project, like all great exploration missions, has a patch and logo, developed by our talented graphics designers at the Adler Planetarium [Images: Orilla Fetro]

Our project became known as “AQUARIUS” (suitably nautical and astronomical at the same time — you can follow their progress on OpenExplorer), and over the course of the next year it grew into an extraordinary voyage of discovery. The first part of the journey involved the team figuring out clever ways they could recover meteorite fragments from the bottom of the Lake. The team settled on the idea of a towed sled with scoops and magnets that could be pulled behind a boat in long transects across the fall field on the bottom of the Lake. They made simulated meteorites in the lab, threw them in shallow water and tested their sled repeatedly. When their design didn’t work quite as expected, or it ran into an unexpected problem, they rolled their sleeves up again and went back into “Big Think” mode, and thought of a way to fix the problem. They deployed and retested. 

After more than a year of work, the team was ready to take their equipment and hit the open water, searching the depths of Lake Michigan for fragments of a space rock that had fallen more than a year before, waiting quietly and patiently to be found in the dark depths of the Lake. I had the great honor of accompanying them on a sunny day in July 2018.

Our port of call was Manitowoc, Wisconsin. Our ship was the SS Neeskay, a research vessel owned and operated by the University of Wisconsin-Milwaukee. Built in 1953, the vessel had served many roles during its time at sea, but was converted into an expeditionary scientific ship in 1970. This summer, it carried a group of us on a hunt for space rocks on the bottom of Lake Michigan…

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This post is the first of two describing my adventures with the Adler Planetarium’s AQUARIUS team. The rest of the story is in the next post:  Into the Deep Void (https://wp.me/p19G0g-Md).