Ask any property inspector, and they’ll tell you one of the maxims of their profession – where there’s moisture, there’s mold. That relationship also holds true for the International Space Station. The interior climate on the ISS is carefully controlled, but if thrown out of whack, potentially dangerous mold could sprout overnight. A new paper by researchers at The Ohio State University explains why – and provides some insights into how we might prevent it if it does happen.
As humans spread into the cosmos, we will take a plethora of initially Earth-bound life with us for the ride. Some might be more beneficial or potentially harmful than others. And there is no lifeform more prevalent on Earth than bacteria. These tiny creatures and fungi, their long-lost cousins on the evolutionary tree, have a habit of clumping together to form a type of structure known as a biofilm. Biofilms are ubiquitous in Earth-bound environments and have been noticed on space missions for decades. But what potential dangers do they pose? More interestingly, what possible problems can they solve? A paper from a group of scientists focused on life support systems in the journal Biofilm provides a high-level overview of the state of the science of understanding how biofilms work in space and where it might need to go for us to establish a permanent human presence off-world.
Artist's impression of Earth in the early Archean with a purplish hydrosphere and coastal regions. Even in this early period, life flourished and was gaining complexity, and distant exoplanets might begin similarly. Credit: Oleg Kuznetsov
Astrobiologists continue to work towards determining which biosignatures might be best to look for when searching for life on other worlds. The most common idea has been to search for evidence of plants that use the green pigment chlorophyll, like we have on Earth. However, a new paper suggests that bacteria with purple pigments could flourish under a broader range of environments than their green cousins. That means current and next-generation telescopes should be looking for the emissions of purple lifeforms.
Humans aren’t the only living things in place onboard the ISS. Bacteria, which has found a way to integrate itself into every biome on Earth, has also found a home in the aseptic microgravity of the space station high above it. Unfortunately, this poses a hazard to both the astronauts that live on the ISS and the station itself. But now, a team of researchers funded by ESA and the Instituto Italiano di Tecnologia (IIT) think they have a solution – make the surfaces on the ISS antimicrobial.
When it comes to plans for future missions to space, one of the most important aspects will be the use of local resources and autonomous robots. This process is known as In-Situ Resource Utilization (ISRU), which reduces the amount of equipment and resources that need to be sent ahead or brought along by a mission crew. Meanwhile, autonomous robots can be sent ahead of a crew and have everything prepared for them in advance.
But what about bacteria that can draw iron from extraterrestrial soil, which would then be used to 3D print metal components for a base? That is the idea that is being proposed by PhD candidate Benjamin Lehner of the Delft University of Technology. On Friday (Nov. 22nd), he defended his thesis, which calls for the deployment of an uncrewed mission to Mars that will convert regolith into useable metal using a bacteria-filled bioreactor.
Spring System at Yellowstone. Photo by Bruce Fouke.
According to a new NASA-funded study that appeared in Astrobiology, the next missions to Mars should be on the lookout for rocks that look like “fettuccine”. The reason for this, according to the research team, is that the formation of these types of rocks is controlled by a form of ancient and hardy bacteria here on Earth that are able to thrive in conditions similar to what Mars experiences today.
The International Space Station (ISS), seen here with Earth as a backdrop. Credit: NASA
For years, scientists have been conducting studies aboard the International Space Station (ISS) to determine the effects of living in space on humans and micro-organisms. In addition to the high levels of radiation, there are also worries that long-term exposure to microgravity could cause genetic mutations. Understanding these, and coming up with counter-measures, is essential if humanity is to become a truly space-faring species.
Interestingly enough, a team of researchers from Northwestern University recently conducted a study with bacteria that was kept aboard the ISS. Contrary to what many suspected, the bacteria did not mutate into a drug-resistant super strain, but instead mutated to adapt to its environment. These results could be vital when it comes to understanding how living beings will adapt to the stressful environment of space.
The International Space Station (ISS), seen here with Earth as a backdrop. Credit: NASA
NASA keeps a close eye on the bacteria inhabiting the International Space Station with a program called the Microbial Observatory (M.O.) The ISS is home to a variety of microbes, some of which pose a threat to the health of astronauts. As part of their monitoring, the M.O. has discovered antibiotic resistant bacteria on the toilet seat on the ISS. Continue reading “Antibiotic Resistant Bacteria has been Found on the Space Station’s Toilet”
The Tesla Roadster sent into space aboard the Falcon Heavy Rocket in early February. Is it teeming with Earthly bacteria? Image: SpaceX
A great celebratory eruption accompanied the successful launch of SpaceX’s Falcon Heavy rocket in early February. That launch was a big moment for people who are thoughtful about the long arc of humanity’s future. But the Tesla Roadster that was sent on a long voyage in space aboard that rocket is likely carrying some bacterial hitch-hikers.
The Falcon Heavy’s first flight. Image: SpaceX
A report from Purdue University suggests that, though unlikely, the Roadster may be carrying an unwelcome cargo of Earthly bacteria to any destination it reaches. But we’re talking science here, and science doesn’t necessarily shy away from the unlikely.
“The load of bacteria on the Tesla could be considered a biothreat, or a backup copy of life on Earth.” – Alina Alexeenko, Professor of Aeronautics and Astronautics at Purdue University.
NASA takes spacecraft microbial contamination very seriously. The Office of Planetary Protection monitors and enforces spacecraft sterilization. Spreading Terran bacteria to other worlds is a no-no, for obvious reasons, so spacecraft are routinely sterilized to prevent any bacterial hitch-hikers. NASA uses the term “biological burden” to quantify how rigorously a spacecraft needs to be sterilized. Depending on a spacecraft’s mission and destination, the craft is subjected to increasingly stringent sterilization procedures.
If a craft is not likely to ever contact another body, then sterilization isn’t as strict. If the target is a place like Mars, where the presence of Martian life is undetermined, then the craft is prepared differently. When required, spacecraft and spacecraft components are treated in clean rooms like the one at Goddard Space Flight Center.
The clean room at Goddard Space Flight Center where spacecraft are sterilized. Image: NASA
The clean rooms are strictly controlled environments, where staff wear protective suits, boots, hoodies, and surgical gloves. The air is filtered and the spacecraft are exposed to various types of sterilization. After sterilization, the spacecraft is handled carefully before launch to ensure it remains sterile. But the Tesla Roadster never visited such a place, since it’s destination is not another body.
The Tesla Roadster in space was certainly manufactured in a clean place, but there’s a big difference between clean and sterile. To use NASA’s terminology, the bacterial load of the Roadster is probably very high. But would those bacteria survive?
The atmosphere in space is most definitely hostile to life. The temperature extremes, the low pressure, and the radiation are all hazardous. But, some bacteria could survive by going dormant, and there are nooks and crannies in the Tesla where life could cling.
This images shows the Orion capsule wrapped in plastic after sterilization, and being moved to a workstand. These types of precautions are mandated by NASA’s Office of Planetary Protection. Image: NASA.
The Tesla is not predicted to come into contact with any other body, and certainly not Mars, which is definitely a destination in our Solar System that we want to protect from contamination. In fact, a more likely eventual destination for the Roadster is Earth, albeit millions of years from now. And in that case, according to Alina Alexeenko, a Professor of Aeronautics and Astronautics at Purdue University, any bacteria on the red Roadster is more like a back-up for life on Earth, in case we do something stupid before the car returns. “The load of bacteria on the Tesla could be considered a biothreat, or a backup copy of life on Earth,” she said.
But even if some bacteria survived for a while in some hidden recess somewhere on the Tesla Roadster, could it realistically survive for millions of years in space?
As far as NASA is concerned, length of time in space is one component of sterilization. Some missions are designed with the craft placed in a long-term orbit at the end of its mission, so that the space environment can eventually destroy any lingering bacterial life secreted away somewhere. Surely, if the Roadster does ever collide with Earth, and if it takes millions of years for that to happen, and if it’s not destroyed on re-entry, the car would be sterilized by its long-duration journey?
That seems to be the far more likely outcome. You never know for sure, but the space-faring Roadster is probably not a hazardous bio-threat, nor a back-up for life on Earth; those are pretty fanciful ideas.
Musk’s pretty red car is likely just a harmless, attention-grabbing bauble.
These are transmission electron microscope images showing tiny magnetofossils containing iron-60, a form of iron produced during the violent explosion and death of a massive star in a supernova. They were deposited by bacteria in sediments found on the floor of the Pacific Ocean. Click for more details. Credit: courtesy Marianne Hanzlik, Chemie Department, FG Elektronenmikroskopie, Technische Universität München
Space and events that transpire there directly affect our lives and those of our remote ancestors including early humans who walked the planet two million years ago. Credit: Bob King
Outer space touches us in so many ways. Meteors from ancient asteroid collisions and dust spalled from comets slam into our atmosphere every day, most of it unseen. Cosmic rays ionize the atoms in our upper air, while the solar wind finds crafty ways to invade the planetary magnetosphere and set the sky afire with aurora. We can’t even walk outside on a sunny summer day without concern for the Sun’s ultraviolet light burning out skin.
So perhaps you wouldn’t be surprised that over the course of Earth’s history, our planet has also been affected by one of the most cataclysmic events the universe has to offer: the explosion of a supergiant star in a Type II supernova event. After the collapse of the star’s core, the outgoing shock wave blows the star to pieces, both releasing and creating a host of elements. One of those is iron-60. While most of the iron in the universe is iron-56, a stable atom made up of 26 protons and 30 neutrons, iron-60 has four additional neutrons that make it an unstable radioactive isotope.
The Crab Nebula, shown here in this image from NASA’s Hubble Space Telescope, is the expanding cloud of gas and dust left after a massive star exploded as a supernova in 1054. Supernovae propel a star’s innards back into space while creating new radioactive isotopes such as iron-60. Credit: NASA, ESA, J. Hester and A. Loll (Arizona State University)
If a supernova occurs sufficiently close to our Solar System, it’s possible for some of the ejecta to make its way all the way to Earth. How might we detect these stellar shards? One way would be to look for traces of unique isotopes that could only have been produced by the explosion. A team of German scientists did just that. In a paper published earlier this month in the Proceedings of the National Academy of Sciences, they report the detection of iron-60 in biologically produced nanocrystals of magnetite in two sediment cores drilled from the Pacific Ocean.
Magnetite is an iron-rich mineral naturally attracted to a magnet just as a compass needle responds to Earth’s magnetic field. Magnetotactic bacteria, a group of bacteria that orient themselves along Earth’s magnetic field lines, contain specialized structures called magnetosomes, where they store tiny magnetic crystals – primarily as magnetite (or greigite, an iron sulfide) in long chains. It’s thought nature went to all this trouble to help the creatures find water with the optimal oxygen concentration for their survival and reproduction. Even after they’re dead, the bacteria continue to align like microscopic compass needles as they settle to the bottom of the ocean.
These are transmission electron microscope images showing tiny magnetofossils containing iron-60, a form of iron produced during the violent explosion and death of a massive star in a supernova. They were deposited by bacteria in sediments found on the floor of the Pacific Ocean. Click for more details. Credit: courtesy Marianne Hanzlik, Chemie Department, FG Elektronenmikroskopie, Technische Universität München
After the bacteria die, they decay and dissolve away, but the crystals are sturdy enough to be preserved as chains of magnetofossils that resemble beaded garlands on the family Christmas tree. Using a mass spectrometer, which teases one molecule from another with killer accuracy, the team detected “live” iron-60 atoms in the fossilized chains of magnetite crystals produced by the bacteria. Live meaning still fresh. Since the half-life of iron-60 is only 2.6 million years, any primordial iron-60 that seeded the Earth in its formation has long since disappeared. If you go digging around now and find iron-60, you’re likely looking at at a supernova as the smoking gun.
Co-authors Peter Ludwig and Shawn Bishop, along with the team, found that the supernova material arrived at Earth about 2.7 million years ago near the boundary of the Pleistocene and Pliocene epochs and rained down for all of 800,000 years before coming to an end around 1.7 million years ago. If ever a hard rain fell.
Reconstruction of Homo habilis at the Westfälisches Museum für Archäologie. Credit: Lillyundfreya / Wikipedia
The peak concentration occurred about 2.2 million years ago, the same time our early human ancestors, Homo habilis, were chipping tools from stone. Did they witness the appearance of a spectacularly bright “new star” in the night sky? Assuming the supernova wasn’t obscured by cosmic dust, the sight must have brought our bipedal relations to their knees.
There’s even a possibility that an increase in cosmic rays from the event affected our atmosphere and climate and possibly led to a minor die-off at the time. Africa’s climate dried out and repeated cycles of glaciation became common as global temperatures continued their cooling trend from the Pliocene into the Pleistocene.
Cosmic rays strike our atmosphere all the time, but their energy is spent striking atoms to create showers of secondary, less energetic particles, a few of which sometimes make it to the ground. Credit: Simon Swordy, University of Chicago, NASA
Cosmic rays, which are extremely fast-moving, high-energy protons and atomic nucleic, rip up molecules in the atmosphere and can even penetrate down to the surface during a nearby supernova explosion, within about 50 light years of the Sun. The high dose of radiation would put life at risk, while at the same time providing a surge in the number of mutations, one of the creative forces driving the diversity of life over the history of our planet. Life — always a story of taking the good with the bad.
The discovery of iron-60 further cements our connection to the universe at large. Indeed, bacteria munching on supernova ash adds a literal twist to the late Carl Sagan’s famous words: “The cosmos is within us. We are made of star-stuff.” Big or small, we owe our lives to the synthesis of elements within the bellies of stars.
