On August 21st, 2018 we learned about

The Chandrayaan-1 spacecraft confirms relatively accessible supplies of ice on the Moon’s surface

If humans get thirsty on their way to Mars, it looks like we’ll be able to stop for drinks on our own Moon. Despite its reputation for being nothing more than a dusty target for asteroid strikes, researchers are solidly convinced that the Moon’s north and south poles are both home to water ice. If there proves to be a significant amount of frozen water, it could be a crucial resource for humans or spacecraft spending time in space.

Cold craters as ice cube trays

While the Moon’s surface is generally a dry, inhospitable place, it’s actually fairly conceivable to find water ice at the north and south poles. The Moon rotates with hardly any tilt to its axis, only 1.54 degrees, compared to the Earth’s 23.5-degree tilt, so the north and south poles don’t experience seasonal changes in their exposure to the Sun. With the Sun never being “overhead” at these locations, deeper craters can cast constant shadows on their interiors, maintaining temperatures below -250 degrees Fahrenheit. At this time, it’s unknown if this water was originally delivered by an icy comet or some other means, but there’s a good chance that it has remained frozen in these craters for a very long time.

The origin of the water might be revealed once a physical sample can be acquired. For now, the ice has been identified by examining a number of features with the Moon Mineralogy Mapper (M3) instrument aboard the Chandrayaan-1 spacecraft. Even with the dust and darkness in these polar craters, the M3 was able to measure the reflectivity, infrared light absorption and other properties that all point to frozen H2O being on the Moon.

Accessible ice

There’s likely more ice buried deeper in the Moon, but these patches are exciting thanks to how close they are to the surface. Even though it likely has a lot of dirt mixed into it, it would still be accessible enough to be of use to humans or robots visiting the Moon in the future. Water is pretty heavy to get off the Earth, so any supplies of water for drinking, irrigating or even splitting to gain access to oxygen, would be a welcome resource for astronauts traveling outside low Earth orbit.

Source: Ice Confirmed at the Moon's Poles, Jet Propulsion Laboratory News

On June 3rd, 2018 we learned about

How an expanding Atlantic ocean may contribute to the world’s next supercontinent

While humans have never known a world without it, the Atlantic Ocean is a relatively new addition to the planet. It started out a smaller lakes and marshlands through the center of a now-scattered supercontinent called Pangea, eventually growing and stretching into the massive body of water we know today. And it’s not actually done growing- every year, a seam down the middle of the Atlantic Ocean, called the Mid-Atlantic Ridge, continues to push outwards, widening the ocean by around two to five centimeters a year. Since the Earth’s circumference isn’t also growing to account for this new land, it got my third grader wondering, “will the Atlantic’s growth squeeze the Pacific Ocean until it’s gone?”

Expanding oceans

From a human time scale, this may seem like a wacky idea- Oceans don’t just disappear, right? Before geologists had developed the currently accepted model of plate tectonics, the Alfred Wegener’s continental drift model would have probably argued against the total destruction of an ocean. Wegener believed that the major land masses, or continents, on Earth slid around each other and the perimeters of the oceans, as if they were two distinct types of crust on our planet. As we’ve learned more about how our planet’s crust grows and recycles itself, we’ve come to realize that the continents and oceans are built as tectonic plates, and that these units may have boundaries through continents and oceans. This model can then better account for the growth of the Atlantic Ocean, but also for the various points of growth and destruction underneath the Pacific Ocean as well.

We now believe that there are around 12 major tectonic plates, and that they’re all moving relative to each other. As it turns out, the Mid-Atlantic Ridge isn’t the only major expansion taking place right now. The Arabian and African plates are also being pushed away from each other thanks to expansion under the Red Sea in a process that likely resembles the early days of the Atlantic Ocean. Given enough time, it’s thought that Africa will be fully separated from the Middle East as the Red and Mediterranean Seas are joined together. At the same time, the Horn of Africa will likely become an island as the Indian Ocean helps fill in the basins around present day Lake Victoria.

The Pacific pushes back

So if expansions are clearly taking place, what about the question of contraction in the Pacific? One complication is that the Pacific Ocean actually sits on more than one tectonic plate, and they’re not all moving in the same way. The East Pacific Rise is another point of tectonic expansion, stretching from Baja California, under Easter Island, and then past the southern tip of New Zealand. It’s actually adding between six to 16 centimeters of crust per year, suggesting that it’s outgrowing the Mid-Atlantic Ridge. However, some of that is undone by the way other plates are interacting. The Nazca plate, which sits between the East Pacific Rise and the coast of Chile, is actually being consumed thanks to this subductive movement. As the Rise pushes the Nazca towards South America, the plate is being pushed down below the continent, raising the Andes Mountains while otherwise being recycled deeper in the Earth.

Squishing together a new supercontinent

At this point, the trend seems to be that the Pacific Ocean will eventually shrink. Australia will likely end up mashed against southern Asia, and North America will be pushed west towards Asia as well, although in a way that may reopen much of the Pacific Ocean. After 100 million more years, there’s actually a decent chance the world will be home to yet another supercontinent. One prediction for this new landmass has been named Amasia, created from the Americas being mashed into Asia, just as the name implies. This model also predicts the eventual joining of South and North America, leaving the world’s land arranged in a giant crescent shape when viewed from the North Pole. There’s a lot of room for speculation at this point of course, so there’s also a chance we could instead end up with Pangea Proxima or Novopangea instead. Don’t let those last two names mislead you though— Pangea isn’t our only model for a supercontinent, as it certainly wasn’t the first or last time all the continents would be mashed together.

Source: Earth: Our Habitable Planet Chapter 13: Evolution of Continents and Oceans by Dr. Jürgen Schieber, Indiana University

On May 6th, 2018 we learned about

NASA launches the InSight mission to figure out how Mars was made

On the morning of May 5, 2018, cheers of excitement went up over the prospect of landing a robot on the most boring part of Mars imaginable. The target location wasn’t picked because we’re running out of interesting features to look at on Mars of course, but because we wanted a relatively “quiet” place for the Interior exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) lander to learn about what’s under Mars. To do that, the lander will essentially listen to the planet’s seismic activity for a year just north of the equator, trying to weed out other disruptions from the activity happening deep in the planet’s core.

Digging in the dirt

For this extended listening session, InSight will land in one spot, then set up shop. In a first, a robotic arm will lower its two primary instruments to the ground where they can then go to work for at least a year of data collection. The Heat Flow and Physical Properties Probe (HP3) will be inserted over 10 feet underground, where it will both heat the surrounding dirt and then measure how quickly that heat travels through the surrounding material. These measurements will then give researchers a good idea about the geological composition of Mars’ surface.

Super-sensitive seismic sensor

The second instrument will sit on the ground in a vacuum chamber further protected by a small dome. This will help block out wind, dust, and other possible sources of “noise.” This is important, because the Seismic Experiment for Interior Structure (SEIS) is so sensitive to vibrations it pick up the movement of ocean waves from as far away as Colorado. Even the movement of a single hydrogen atom is said to be detectable, which is why a tiny leak in the protective vacuum chamber required the entire InSight mission be delayed by two years— to truly be effective, the SEIS data must be as free of unexpected disruptions as possible.

On Mars, those vibrations will tell us a lot about the planet. Unlike the Earth’s moving, crunching and melting geology, Mars stopped churning 20 to 50 million years after it was formed. The quakes the Red Planet does experience are tied to the gradual cooling and contraction of the planet as a whole, and measuring the frequency and intensity of those quakes will tell us more about how the planet was formed in the first place. Naturally, a device as sensitive as SEIS will pick up other activity as well, meaning we can look forward to a log of asteroid impacts around the planet as they happen.

If this weren’t enough, we’ll also be tracking how our stationary lander’s position shifts throughout the year. Nobody is expecting a marsquake to start moving InSight around, but Mars’ axis of rotation is known to be gradually changing. So as we track signals from the lander, we’ll be able to detect how that telemetry shifts over time.

Mini-mission

Some of that will be made easier by the two other bots sent to space with InSight. Two mini-satellites in a class often referred to as “cubesats,” will be going into orbit around Mars to help track and report on InSight’s landing process. They’re not strictly necessary for InSight’s success, which is great since they’re actually an experiment themselves. While many cubesats now orbit the Earth,  MarCO-A and MarCO-B (aka Wall-E and Eva, thanks to their gas propulsion thrusters’ resemblance to a certain fire-extinguisher) will be the first such devices to visit another planet. If they prove up to the task, they could herald a new way for us to explore our solar system in a more modular, inexpensive manner.


My five-year-old asked: What kind of spaceship did they send the lander on?

InSight and the two cubesats were sent on an Atlas V rocket. The relatively lightweight payload and powerful rocket enabled the mission to launch from Vanderberg Air Force Base in California, rather than Cape Canaveral in Florida. While an east coast launch is generally beneficial to help push interplanetary missions out of Earth’s orbit, InSight planners wanted to avoid crowded schedule in Florida, opting for a bigger rocket from California instead. As such, this was the first time an interplanetary mission launched from the west coast.

Source: Meet InSight: The Mission To Measure Marsquakes and Unlock the Red Planet by Emily Lakdawalla, Popular Mechanics

On April 25th, 2018 we learned about

Mini model meteorites demonstrate how well hot rocks can deliver water to dry planets

While we live on an impressively wet planet today, the Earth probably didn’t start out with our lush collections of rivers, lakes and oceans. With no obvious way for the planet’s iron and other minerals to have spontaneously transmuted into H2O billions of years ago, scientists have long suspected that our water was instead delivered from space via icy objects like comets. Further research found that our water looked more like the water found on icy asteroids like Ceres, which was clearly abundant in the asteroid belt, but it still posed a problem. Asteroids tend to burn and explode a lot when they get too close to the Earth, so how would any of their water survived long enough to help soak our planet?

Proxy-asteroid projectiles

With no asteroids or spare planets at their disposal, researchers from Brown University turned to the Vertical Gun Range at the NASA Ames Research Center to simulate icy impactors. Marble-sized projectiles were fabricated to match the composition of carbonaceous chondrites, or meteorites suspected of being formed in ancient, icy asteroids. The miniature proxy-meteors were then fired at a chunk of dry pumice powder, which served as their stand-in for the once-parched surface of the Earth.

The small impactors hit their targets at more than 11,000 miles-per-hour, releasing heat and an impressive amount of debris in all directions. As with real asteroid impacts, enough heat was generated in these collisions to outright destroy some material, including some of the water ice. However, some of the mineral content also melted, which weirdly enough was key to some of the water’s survival. Because the rock melted and re-cooled so quickly, it could capture some of the water inside the resulting glass, keeping it “safe” from vaporizing. Additional water was similarly captured by flying breccias— random debris thrown and heated by the impact that were hot enough to become “welded” together.

Making sense of previous predictions

This experiment not only helps explain some of the water on Earth, but also some of the confusing H2O around the solar system. Since previous estimates found that asteroid impacts should vaporize water, researchers had a hard time explaining the presence of water in impact craters on places like the Moon and Mercury. The physical test proved that those estimates hadn’t captured the full complexity of such an impact, and that delivering water via screamingly-fast hunks of icy rock is apparently more practical than you might think.


My five-year-old asked: What does the Vertical Gun Range look like?

“Gun” may be a misleading term here, because the equipment in question doesn’t really look much like pistol, rifle or cannon, at least outside science fiction. A large barrel launches a projectile into an enclosed, reinforced chamber. That chamber is outfitted with a number of sensors and cameras so that researchers can learn more details about the behavior of whatever collision is being studied. NASA has more on the AVGR in this handy PDF.

Source: Projectile cannon experiments show how asteroids can deliver water by Brown University, Phys.org

On April 19th, 2018 we learned about

A meteorite delivered diamonds carrying traces of our solar system’s less successful protoplanets

Building a planet out of dust isn’t easy. Sure, the recipe basically requires innate forces like gravity to do a lot of the work, but not every clump of debris successfully forms into a durable planet. Those first steps are called protoplanets, and while we’ve seen them around other stars, we’ve only recently found evidence of the protoplanets that helped build the planets in our own solar system.

Learning from dirty diamonds

The evidence found in diamonds carried to Earth in a meteorite that struck the Earth in 2008. Those diamonds carried small bits of other metals and minerals that were present when the diamond was formed. The composition and structure of this extra material, known as inclusions, can tell us a lot about the conditions that created the diamond.

In this case, the structure of the diamond indicates that it was formed as an achondrite— a rock formed in an object large and hot enough to create a metallic core inside a layer of rock. That could include very large asteroids, but other features of these diamonds make it more likely to have been formed in a larger protoplanet instead. The inclusions also show that these diamonds were formed under at least 20 gigapascals of pressure, well beyond diamond’s normal elastic breaking point. With that reference point, geophysicists can estimate that the protoplanet that created these diamonds was somewhere between the size of Mercury and Mars.

This may seem like a crazy amount of information to infer from a single space rock, but we’ve been reading history from diamonds here on Earth for years. Actually, we’ve been getting history out of the Earth, as diamonds are known to carry information about the formation and movement of materials deep under the Earth’s crust, carrying them to the surface like shiny time-capsules, including deposits of water over a 100 miles below the Earth’s surface.

Potential planets from the past

None of this suggests that we have a new planet forming next door. Simulations of our solar system’s formation predicted that multiple protoplanets formed within 10 million years of our Sun’s formation. While at least eight of those objects managed to survive long enough to become the planets we know today, the diamonds found in the 2008 meteorite are probably just pieces of some of the other protoplanets that were destroyed in collisions in a more crowded solar system.

 

Source: Diamonds in Meteorite May Hail from Our Ancient Solar System by Doris Elin Slazar, Space.com

On April 1st, 2018 we learned about

Satellites can spot underground supplies of volcanic magma from space

The best way to find volcanic activity brewing under the ground may be to look from space. While magma and gas aren’t directly visible until a volcano actually erupts, their accumulation underground can cause the ground surrounding a volcano to deform. These deformations aren’t necessarily big enough to be noticed by the naked eye, they can be detected by special GPS sensors staked in the ground surrounding the volcano. However, these sensitive instruments can’t be everywhere at once, which is why researchers from Penn State are looking into looking for these subtle shifts in the ground from over 1000 miles above the Earth’s surface.

While a lot of information can be gleaned from visual photography, the imaging in this study was actually a form of radar. Known as Interferometric Synthetic-Aperture Radar (InSAR), this technology creates topographic maps precise enough to show changes in elevation as small as a one-third of an inch. This allowed them to track a three-inch bulge in the ground north of the Masaya volcano in Nicaragua which was attributed to a growing pool of magma that was otherwise undetected. It’s not that the traditional GPS monitors weren’t sensitive to these shifts, but that they just didn’t have the range of satellite imaging, and thus couldn’t pick up on changes in the ground two miles away from the volcano’s open crater.

Better predictions from bigger pictures

This wider range of detection then offers a number of benefits. By monitoring a larger swath of territory, we increase the odds that we’ll detect deformations in terrain that could predict eruptions before people are in danger. The Masaya volcano is known to have blasted ash and lava in a radius of 30 miles during a 1772 eruption, which is probably the kind of thing the two million people that now live within 12 miles of the volcano would like to be ready for.

Beyond human safety, getting more data about volcanic activity will help researchers better understand how volcanoes work in the first place. A build-up of magma two miles from the actual volcano shows that there’s a lot more to these systems than the cone we see on the surface. If more of that system can be tracked and measured with a satellite, it will help build more accurate models about how magma and pressure leads to eruptions in the first place. That will then make future observations, possibly from space, all the more useful in predicting eruptions in other locations around the world.

Source: Wider coverage of satellite data better detects magma supply to volcanoes by David Kubarek, Penn State News

On March 15th, 2018 we learned about

Burning coal was likely the key component of the world’s worst extinction event

As dramatic as a good asteroid strike can be, giant falling space rocks aren’t the only thing that has wiped out life on Earth. The mass extinction that ended the Age of Dinosaurs was actually the fifth time nearly everything died. Before the first dinosaur was ever born, an extinction event known as “The Great Dying” took place, a horrific series of events that choked, poisoned or burned multitudes of animals on both the land and in the seas. 70 percent of terrestrial vertebrates and 90 percent of sea life went extinct during this time 252 million years ago, with the devastation taking at least 10 million years to show signs of recovery. While many of the terrible details about how things died have previously been discovered, research out of Utah is helping piece together what started all this destruction in the first place.

Indirect effects of eruptions

With no sign of an asteroid strike in sight, researchers have been looking for other events that might have knocked the world’s climate and atmosphere so far out of balance that it became toxic for most creatures to breathe. There’s evidence that massive volcanic eruptions took place in Asia around the end of the Permian period, but they predated the fossil records of the Great Dying by 300,000 years. Furthermore, analysis of rock layers from Utah don’t show signs of direct volcanic impact at that time— instead of the metals like nickel that you’d expect to  be carried from underground by a volcano’s magma, deposits from the end of the Permian have extra mercury, lead and carbon-12, all of which are associated with burning coal.

The picture that then emerged was one where volcanic eruptions were a trigger for The Great Dying, but not the exact cause, as their ash wasn’t influential enough to reach around the world, such as to what is now Utah. Instead, the erupting lava seems to have hit and ignited massive coal beds that were originally deposited in Asia in the Carboniferous period. As that coal burned, it spread around the world, setting off the bigger chain of events that led to mass extinctions.

From coal to corrosion

The fallout from the burning coal might be enough to make a prehistoric therapsid dream of asteroid strikes. The soot from the coal led to severe changes in the planet’s climates, raising temperatures, and acidity, of the oceans. As the oceans warmed, barium levels indicate that more methane was released from the sea floor, trapping even more heat in the atmosphere. After all this, an abundance of pyrite that was formed at this time suggests that the oceans became depleted of oxygen, naturally leading to more dead marine animals. Those deaths were so abundant that the bacteria that set to work consuming corpses released an immense amount of hydrogen sulfide gas (H2S), bringing us to what happened to the poor creatures living on land.

Hydrogen sulfide gas is toxic in large doses, but more importantly can react with moisture in the air to form acidic sulfur dioxide (SO2). So as bacteria tried to clean up the oceans, their waste led to acid rain that started killing plant life on land. Between the toxic, burning atmosphere and a lack of plants, the food chain understandably would have collapsed, taking both herbivores and the carnivores that ate them with it.

Current costs of burning coal

The scariest part of all this is probably just how mundane the idea of burning coal seems today. Thanks to industrialization, we don’t even need the help of a volcano to burn massive amounts of the stuff around the world. Thankfully, air quality legislation has managed to take steps to reign in acid rain, so we’re not corroding our forests into pulp right now. However, the seas do seem to be starting to relive some of the Great Dying, as temperatures and pH levels have been rising in various patches of the ocean. Thankfully, unlike a volcano or asteroid strike, there’s more we can actually do to head off The Great Dying II, because that’s definitely a sequel nobody wants to ever see.

Source: Burning coal may have caused Earth’s worst mass extinction by Dana Nuccitelli, The Guardian

On February 21st, 2018 we learned about

Tsunamis may soon be detected with a single hydrophone and a decent amount of math

Tsunamis aren’t subtle, but they do still manage to be surprising. They’re created by earthquakes under the sea, sometimes so far from a coast that people will have no idea any seismic activity occurred. Then, once the surge of water reaches a shoreline, anyone there has very little time to react and escape the area. As we get better at monitoring the ocean floor for earthquakes, these events are becoming slightly easier to predict, but the sea floor is so vast that it’s not the most practical endeavor. However, new research is suggesting that the key to catching tsunamis earlier may come down to listening to the sea, and acoustic gravity waves in particular, in just the right way.

Massive amounts of movement

When an earthquake occurs in the ocean, there’s obviously a lot of shaking and vibrating going on. In addition to massive amounts of displaced water, a quake will send out acoustic gravity waves (AGWs) in every direction. These waves are a bit like a hybrid of sound waves moving laterally through the air, and the gravity-sensitive waves you see shaping fluids like the average waves near a beach. This has made AGWs tricky to study and model, since they don’t follow the exact patterns we see in more common wave activity. One trait that has stood out, however, is that an AGW can move through the ocean at the speed of sound across huge distances. Because of their impressive sizes and speeds, researchers have long hoped that they could be detected well in advance of a tsunami’s arrival, buying people more time to get to safety.

The difficulty hasn’t been detecting the AGWs, but making sense of them. Fortunately, scientists from the University of Cardiff are now suggesting that this kind of analysis is not only possible, but practical even with only a single hydrophone sensor in the ocean to detect the wave. The distinct shape and speed of any AGW should reveal various aspects about the earthquake that created them. With more information in the system, such as details about the suspected fault location, researchers state that the tsunami’s amplitude and potential impact on a shoreline can be predicted. Once compiled, these data could then be used to trigger tsunami alarms in the tsunami’s path, giving people crucial time to find safety.

Heard through single hydrophone

On a basic level, this is similar to the tsunami alarms we have today. Devices known as dart buoys are anchored at sea, and can then detect unusual pressure changes in the water below them. This works if the buoys are in the tsunami’s path, which then requires that they’re located in all the right locations at all the right times. Measuring AGWs, however, don’t require that kind of specific placement. Because AGWs expand in multiple directions from an earthquake’s epicenter, hydrophones in any direction could detect clues about the formation of a tsunami. This then leads to a much more practical system for early warnings, increasing the chances that an alarm will reach people with enough time to get away from the water.

Source: Could underwater sound waves be the key to early tsunami warnings? by Cardiff University, Science Daily

On January 15th, 2018 we learned about

Sifting through the causes, concepts and misconceptions of quicksand

Despite growing up in tame suburban landscape of sidewalks and lawns, my kids are very concerned about how to deal with quicksand. I can only assume that repeated viewings of Wreck It Ralph and The Force Awakens (no Princess Bride yet) have helped build up the mystery of watery sand, particularly since fiction usually portrays it as something perilous that can capture a hero without warning. Of course, having seen DuckTales and G.I. Joe, I know that my kids’ concerns are unfounded, and that we’ll never run into quicksand near our home. Or so I thought.

Sources of soupy sand

Well, I was right about the general composition of quicksand. It’s any loose, grainy soil with a large concentration of water in it to turn it into a fluid. One of the most common places to run into quicksand is at the beach when water rushes into loose sand. Sand that’s only moist is likely to clump together, but with enough water flowing through the sand, each grain will separate and basically roll around independently of each other. The resulting soup can then look like solid ground from above, but has a consistency just a bit thicker than water when you step into it. While quicksand in nature is going to involve water, Mark Rober has a great demonstration of how sand can behave like a fluid using air as well.

Now, not every puddle turns into quicksand, obviously, mainly because the water needs to flow in a way that helps separate the grains of sand or soil. A great way to break up clumped soil turns out to be vibrations from earthquakes, and tremblors are a major cause of quicksand in all kinds of environments. Quake-produced quicksand is actually a significant safety hazard, not so much for people suddenly in need of conveniently placed vines, but for buildings that partially sink into the ground, stressing or warping their structural integrity. As such, researching the exact combinations of vibrations, soil composition and water flow has been the subject of research looking to predict which locations are most likely to suddenly turn to soup when the ground shakes.

Saving yourself from sinking

Aside from our next trip to the beach, the intersection of quakes and quicksand adds sudden legitimacy to my kids’ concerns about sinking into the soil. We don’t live especially close to a marsh or lake, but earthquakes aren’t uncommon in the Bay Area. Unless a water pipe bursts at just the right spot, it still seems unlikely that we’ll run into quicksand nearby, but there aren’t many conveniently placed vines to grab hold of if we did. Despite what cartoons and movies have taught us, that’s probably ok, since most quicksand isn’t likely to swallow you up in the first place.

While drowning in fluidized soil can happen, most instances of quicksand in nature aren’t that deep, so you aren’t likely to be fully submerged in order to drown. You might get stuck though, and trying to lift your legs straight up to take a step would be very difficult. Your best option is to try to lean back and spread your arms, letting buoyancy help lift you up. Small movements of your legs will help loosen them, but sharp vertical yanks aren’t going to be practical. This isn’t to say that people don’t die after getting stuck in quicksand, but some of those cases are due to other factors, like rising water levels, than the quicksand on its own.

Source: How Quicksand Works by Kevin Bonsor, How Stuff Works

On January 4th, 2018 we learned about

Fossilized microbes show surprising biodiversity from 3.4 billion years ago

Most rocks on the Earth’s surface don’t last more than 200 million years before erosion or other forces get the best of them. Sure, that’s older than any dinosaur, but it’s only a tiny slice of our planet’s 4.5-billion-year history. Thankfully, rocks and crystals from the Earth’s early days do turn up here and there, helping us understand what our planet once looked like, and even more intriguing, who first called it home. That latter point is being revealed by 3.4-billion-year-old rocks from Australia, which have been found to not only contain fossilized microorganisms, but evidence of a surprisingly diverse ecosystem at a time when our planet was just beginning to be habitable.

Combing through fossils for traces of chemistry

The fossilized microorganisms weren’t multicellular animals of course, so these ancient rocks offered no bones or organs to study. Instead, researchers studied each singled-celled organism with secondary ion mass spectroscopy (SIMS). This technology allowed researchers to compare variations of carbon atoms, or isotopes, in the fossils and surrounding stone. The ratios of carbon-12 to carbon-13 was then be used to determine how each microbe functioned when it was alive, as those isotopes will accumulate differently in different metabolic conditions.

Differences in these early prokaryotes‘ metabolisms suggest that even 3.4 billion years ago, life had evolved a few different ecological niches. One group was apparently a methane producer, while another powered its metabolism by consuming methane. A third fossil showed signs of primitive photosynthesis that, unlike today’s plants, didn’t produce oxygen (which would have been toxic to these organisms). A microbe from an earlier study rounds out the bunch, as it relied on sulfur as its primary food-source.

Is life less unusual than we assumed?

This version of Earth certainly wouldn’t be habitable by today’s standards, but it’s an amazing degree of sophistication for a planet that had probably only had solid ground for 600 million years. This suggests that either the Earth was intensely lucky at an early age, or that life may be a bit more tenacious than we once thought. If it’s the latter, researchers suspect that this aggressive microbial timeline may have played out on other planets as well. It wouldn’t mean that other planets have the same complex organisms we do here, but that getting some microbes growing in the first place isn’t such a long-shot.

Until we get probes out to places like Europa, Titan or Enceladus, the best location to find extraterrestrial microbes may be Mars. This wouldn’t be to find microbes alive today, but to look for traces of similar fossils from the days when Mars was likely a more habitable planet.

Source: