Last week, the mainstream news was filled with headlines about K2-18b — an exoplanet some 124 light-years away from Earth that 98% of the population had never even heard about. Even astronomers weren’t aware of its existence until the Kepler Space Telescope picked it out back in 2015, just one of the more than 2,700 planets the now defunct observatory was able to identify during its storied career. But now, thanks to recent observations by the James Web Space Telescope, this obscure planet has been thrust into the limelight by the discovery of what researchers believe are the telltale signs of life in its atmosphere.

Well, maybe. As you might imagine, being able to determine if a planet has life on it from 124 light-years away isn’t exactly easy. We haven’t even been able to conclusively rule out past, or even present, life in our very own solar system, which in astronomical terms is about as far off as the end of your block.

To be fair the University of Cambridge’s Institute of Astronomy researchers, lead by Nikku Madhusudhan, aren’t claiming to have definitive proof that life exists on K2-18b. We probably won’t get undeniable proof of life on another planet until a rover literally runs over it. Rather, their paper proposes that abundant biological life, potentially some form of marine phytoplankton, is one of the strongest explanations for the concentrations of dimethyl sulfide and dimethyl disulfide that they’ve detected in the atmosphere of K2-18b.

As you might expect, there are already challenges to that conclusion. Which is of course exactly how the scientific process is supposed to work. Though the findings from Cambridge are certainly compelling, adding just a bit of context can show that things aren’t as cut and dried as we might like. There’s even an argument to be made that we wouldn’t necessarily know what the signs of extraterrestrial life would look like even if it was right in front of us.

Life as We Know It

Credit where credit is due, most of the news outlets have so far treated this story with the appropriate amount of skepticism. Reading though the coverage, Cambridge’s findings are commonly described as the “strongest evidence yet” of potential extraterrestrial life, rather than being treated as definitive proof. Well, other than the Daily Mail anyway. They decided to consult with ChatGPT and other AI tools in an effort to find out what lifeforms on K2-18b would look like.

So, AI-generated frogmen renders not withstanding, what makes these findings so difficult to interpret? For one thing, we have very little idea of what extraterrestrial life would actually be like, so proving that it exists is exceptionally difficult. Scientists have precisely one data point for what constitutes as life, and you’re sitting on it. We only know what life on Earth looks like, and while there’s an incredible amount of biodiversity on our home planet, it all still tends to play by the same established rules.

We assume those rules to be a constant on other planets, but that’s only because we don’t know what else to look for. Consider that the bulk of our efforts in the search for extraterrestrial intelligence (SETI) thus far have been based on the idea that other sentient beings would develop some form of radio technology similar to our own, and that if we simply pointed a receiver at their star, we would be able to pick up their version of I Love Lucy.

This is a preposterous presupposition, which doesn’t even make much sense when compared to humanity’s history. Consider the science, literature, and art that humankind was able to produce before the advent of the electric light. Now imagine that Proxima Centauri’s answer to Beethoven is putting the finishing touches on their latest masterpiece as our radio telescope silently checks their planet off the list of inhabited worlds because it wasn’t emanating any RF transmissions we recognize.

Similarly, here on Earth dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) are produced exclusively by biological processes. DMS specifically is so commonly associated with marine phytoplankton that we often associate its smell with being in proximity of the sea. This being the case, you could see how finding large quantities of these gases in the atmosphere of an alien planet would seem to indicate that it must be teaming with aquatic life.

But just because that’s true on Earth doesn’t mean it’s true on K2-18b. We know these gases can be created abiotically in the laboratory, which means there are alternative explanations to how they could be produced on another planet — even if we can’t explain them currently. Further, a paper released in November 2024 pointed out that DMS was detected on comet 67P/Churyumov–Gerasimenko by the European Space Agency’s Rosetta spacecraft, indicating there’s some unknown method by which it can be produced in the absence of any biological activity.

Finding What You’re Looking For

All that being said, let’s assume for the sake of argument that the presence of dimethyl sulfide and dimethyl disulfide was indeed enough to confirm there was life on the planet. You’d still need to confirm beyond a shadow of a doubt that those gases were present in the atmosphere. So how do you do that?

Within our own solar system, you could send a probe. Which is what’s been suggested to investigate the possibility that phosphine gas exists on Venus. But remember, we’re talking about a planet that’s 124 light-years away. In this case, the only way to study the atmosphere is through spectroscopy — that is, examining the degree to which various wavelengths of light (visible and otherwise) are blocked as they pass through it.

This is, as you may have guessed, easier said than done. The amount of data you can collect from such a distant object, even with an instrument as powerful as the James Webb Space Telescope is minuscule. You need to massage the data with various models to extract any useful information from the noise, and according to some critics, that’s when bias can creep in.

In a recently released paper, Jake Taylor from the University of Oxford argues that the only reason Nikku Madhusudhan and his team found signs of DMS and DMDS in the spectrographic data is because that’s what they were looking for. Given their previous research that potentially detected methane and carbon dioxide in the atmosphere of K2-18b, it’s possible the team was already primed to find further evidence of biological processes on the planet, and were looking a bit too hard to find evidence to back up their theory.

When analyzing the raw data without any preconceived notion of what you’re looking for, Taylor says there’s “no strong statistical evidence” to support the detection of DMS and DMDS in the atmosphere of K2-18b. This conclusion itself will need to be scrutinized, of course, though it does have the benefit of Occam’s razor on its side.

In short, there may or may not be dimethyl sulfide and dimethyl disulfide gases in the atmosphere of K2-18b, and that may or may not mean there’s potentially some form of biological life in the planet’s oceans…which it may or may not actually have. If you’re looking for anything more specific than that, the science is still out.

If you had to guess, what do you think it would take to build an ocean-going buoy that could not only survive on its own without human intervention for more than two years, but return useful data the whole time? You’d probably assume such a feat would require beefy hardware, riding inside an expensive and relatively large watertight vessel of some type — and for good reason, the ocean is an unforgiving environment, and has sent far more robust hardware to the briny depths.

But as Wayne Pavalko found back in 2016, a little planning can go a long way. That’s when he launched the first of what he now calls Maker Buoys: a series of solar-powered drifting buoys that combine a collection of off-the-shelf sensor boards with an Arduino microcontroller and an Iridium Short-Burst Data (SBD) modem in a relatively simple watertight box.

He guessed that first buoy might last a few weeks to a month, but when he finally lost contact with it after 771 days, he realized there was real potential for reducing the cost and complexity of ocean research.

Wayne recalled the origin of his project and updated the audience on where it’s gone from there during his 2024 Supercon talk, Adventures in Ocean Tech: The Maker Buoy Journey. Even if you’re not interested in charting ocean currents with homebrew hardware, his story is an inspirational reminder that sometimes a fresh approach can help solve problems that might at first glance seem insurmountable.

DIY All the Way

As Dan Maloney commented when he wrote-up that first buoy’s journey in 2017, the Bill of Materials for a Maker Buoy is tailored for the hobbyist. Despite being capable of journeys lasting for several thousand kilometers in the open ocean, there’s no marine-grade unobtainium parts onboard. Indeed, nearly all of the electronic components can be sourced from Adafruit, with the most expensive line item being the RockBLOCK 9603 Iridium satellite modem at $299.

Even the watertight container that holds all the electronics is relatively pedestrian. It’s the sort of plastic latching box you might put your phone or camera in on a boat trip to make sure it stays dry and floats if it falls overboard. Wayne points out that the box being clear is a huge advantage, as you can mount the solar panel internally. Later versions of the Maker Buoy even included a camera that could peer downward through the bottom of the box.

Wayne says that first buoy was arguably over-built, with each internal component housed in its own waterproof compartment. Current versions instead hold all of the hardware in place with a 3D printed internal frame. The bi-level framework puts the solar panel, GPS, and satellite modem up at the top so they’ve got a clear view of the sky, and mounts the primary PCB, battery, and desiccant container down on the bottom.

The only external addition necessary is to attach a 16 inch (40 centimeter) long piece of PVC pipe to the bottom of the box, which acts as a passive stabilizer. Holes drilled in the pipe allow it to fill with water once submerged, lowering the buoy’s center of gravity and making it harder to flip over. At the same time, should the buoy find itself inverted due to wave action, the pipe will make it top-heavy and flip it back over.

It’s simple, cheap, and incredibly effective. Wayne mentions that data returned from onboard Inertial Measurement Units (IMUs) have shown that Maker Buoys do occasionally find themselves going end-over-end during storms, but they always right themselves.

Like Space…But Wetter

Early on in his presentation, Wayne makes an interesting comparison when talking about the difficulties in developing the Maker Buoy. He likens it to operating a spacecraft in that your hardware is never coming back, nobody will be able to service it, and the only connection you’ll have to the craft during its lifetime is a relatively low-bandwidth link.

But one could argue that the nature of Iridium communications makes the mission of the Maker Buoy even more challenging than your average spacecraft. As the network is really only designed for short messages — at one point Wayne mentions that even sending low-resolution images of only a few KB in size was something of an engineering challenge — remotely updating the software on the buoy isn’t an option. So even though the nearly fifty year old Voyager 1 can still receive the occasional software patch from billions of miles away, once you drop a Maker Buoy into the ocean, there’s no way to fix any bugs in the code.

Because of this, Wayne decided to take the extra step of adding a hardware watchdog timer that can monitor the buoy’s systems and reboot the hardware if necessary. It’s a bit like unplugging your router when the Internet goes out…if your Internet was coming from a satellite low-Earth orbit and your living room happened to be in the middle of the ocean.

From One to Many

After publishing information about his first successful Maker Buoy online, Wayne says it wasn’t long before folks started contacting him about potential applications for the hardware. In 2018, a Dutch non-profit expressed interest in buying 50 buoys from him to study the movement of floating plastic waste in the Pacific. The hardware was more than up to the task, but there was just one problem: up to this point, Wayne had only built a grand total of four buoys.

Opportunities like this, plus the desire to offer the Maker Buoy in kit and ready to deploy variants for commercial and educational purposes, meant Wayne had to streamline his production. When it’s just a personal project, it doesn’t really matter how long it takes to assemble or if everything goes together correctly the first time. But that approach just won’t work if you need to deliver functional units in quantities that you can’t count on your fingers.

As Wayne puts it, making something and making something that’s easily producible are really two very different things. The production becomes a project in its own right. He explains that investing the time and effort to make repetitive tasks more efficient and reliable, such as developing jigs to hold pieces together while you’re working on them, more than pays off for itself in the end. Even though he’s still building them himself in his basement, he uses an assembly line approach that allows for the consistent results expected by paying customers.

A Tale Well Told

While the technical details of how Wayne designed and built the different versions of the Maker Buoy are certainly interesting, it’s hearing the story of the project from inception to the present day that really makes watching this talk worthwhile. What started as a simple “What If” experiment has spiraled into a side-business that has helped deploy buoys all over the planet.

Admittedly, not every project has that same potential for growth. But hearing Wayne tell the Maker Buoy story is the sort of thing that makes you want to go dust off that project that’s been kicking around in the back of your head and finally give it a shot. You might be surprised by the kind of adventure taking a chance on a wild idea can lead to.