How introducing microbial life to Mars can make it livable for humans
In order to build a second Earth, we need to look at how the first one was made.
- Humanity dreams of becoming an interplanetary species, but no other planet in our solar system can currently support complex life.
- In order to make a planet like Mars hospitable for us, we'll have to engage in a massive, decades-long terraforming effort.
- Much of what makes Earth livable, such as breathable air, tolerable temperatures, and so on, are the result of microbial activity from Earth's early history. Can we use microbial life to make the same changes on Mars?
Three billion years ago, Earth would not have been all that pleasant for humans. It was covered in active volcanoes, spewing out carbon dioxide and water vapor. Single-celled life scraped by on a diet of sulfur. Most of the atmosphere consisted of carbon dioxide, methane, and other greenhouse gases, leaving the air toxic for us and most other modern life on Earth.
Then, about 2 and a half billion years ago, something happened. With what amounts to a snap of the fingers in geologic timescales, the atmosphere was pumped full of oxygen in what we call the Great Oxygenation Event. The abundance of oxygen meant that new, more diverse kinds of life could take a hold on the young planet, such as Eukaryotes. Fast-forward a few billion years, and complicated, multicellular life like ourselves are walking around the planet.
So where did all of this oxygen come from? Today, we think that nearly all of the oxygen on Earth came from cyanobacteria, tiny, blue-green, single-celled life that had the innovative idea of using sunlight to bake water and carbon dioxide into sugar for energy — that is, photosynthesis. Unfortunately for the cyanobacteria, photosynthesis makes the unappealing byproduct of oxygen, which they throw away into their environment.
Every breathe we take, we owe to cyanobacteria, and this influx of oxygen into our environment is ultimately responsible for why modern Earth is so accommodating to life. But what Earth giveth, Earth also taketh away. Whether it's because of climate change, nuclear war, a global pandemic, or some unknown catastrophe, eventually we'll want a new home. But our closest, best hope for a new home — Mars — doesn't have any oxygen.
It doesn't have much of an atmosphere at all, really.
This said, scientists are hoping to recreate the Great Oxygenation Event on Mars much in the same way it happened on Earth; by using microbial life to build the environment for us.
Terraforming Mars with microbes
An artist's depiction of a Martian terraforming effort's progression.
While Mars might be different from early Earth in many ways, it does possess some key characteristics that could make a microbial terraforming project work. Mars has an atmosphere that's 95 percent carbon dioxide, which provides half of the ingredients needed for cyanobacteria to make oxygen. The other ingredient, water, is admittedly scarce on the Red Planet, but we've seen evidence that it exists. We know that ice is abundant in the poles, so much so that if we were to melt them, Mars would be covered in an 18-foot-deep ocean.
There's already some liquid water that exists on Mars, to be sure — just in very scant amounts. We've seen features on Mars called recurring slope lineae, which are dark lines that advance down the sides of hills during the Martian summer and fade away during the winter. These dark lines are thought to be flows of water that come and go with the seasons.
This image of the side of a Martian crater shows recurring slope lineae. The dark lines descending from the slope of the crater come and go with the seasons, which may indicate flowing water.
So, to terraform Mars, we would start with areas where we know liquid water exists and dump a lot of cyanobacteria there. Admittedly, it would be a bit more of a sophisticated operation than that makes it sound, but that's the gist of the idea. We would also want to include microbes that produce greenhouse gases.
Mars has the opposite problem as Earth; we want to make Mars hotter and thicken its atmosphere, so its polar ice can melt. More water means more opportunities for microbial life to do its work. Not to mention that the current climate on Mars is much too chilly for even the hardiest human — it averages at about minus 81 degrees Fahrenheit, although the temperature can vary wildly.
The idea of using microbes to kickstart a terraforming project on Mars is so promising that NASA has already begun preliminary tests. The Mars Ecopoiesis Test Bed is a proposal for a device to be included with future robotic missions to Mars. It would look something like a drill with a hallow chamber inside. The drill would bury itself in the Martian soil, preferably somewhere with liquid water. A container full of cyanobacteria would be released into the chamber, and sensors would detect whether the microbial life produce any oxygen or other byproducts.
The first phase of this project was conducted in a simulated Martian environment here on Earth, and the results were positive. But even still, there are some major challenges we'll have to meet if we want to use microbially terraform Mars on a large-scale.
The Mars Ecopoiesis Test Bed.
Mars lacks something very necessary for life-giving planets: a magnetosphere. Mars used to have a magnetic field that protected the planet. We've found magnetized rocks on the surface indicating that this was the case, but at some point, the magnetic field just disappeared, and we don't know for certain what happened. Without a magnetosphere, the planet's surface is bombarded by solar radiation, which will make larger, more complex life difficult to sustain.
This "solar wind" also blows away the Martian atmosphere. So, even if we do coax microbial life into producing oxygen and other gasses, much of it will simply float away into space.
These images show different elements escaping from the Martian atmosphere. From left to right, the images show carbon, oxygen, and hydrogen floating away to space.
Fortunately, these challenges are not insurmountable. In the short term, we'll likely construct dome-like habitats to protect both us, our cyanobacteria, and our new atmosphere from the solar wind. In the long term, NASA scientists have proposed placing a powerful magnet in fixed orbit between Mars and the Sun. This magnet will redirect the solar wind, shielding the Martian atmosphere. As microbial life continues to output oxygen and greenhouse gases into the Martian atmosphere, the planet will warm up, the ice caps will melt into oceans, and Mars may very well become our second home.
- A Magnetotail Around Mars Would Cause the Planet to Terraform Itself ›
- Should We Use Comets and Asteroids to Terraform Mars? - Big Think ›
- The Cheapest Way to Terraform Mars - Big Think ›
Northwell Health CEO Michael Dowling has an important favor to ask of the American people.
- Michael Dowling is president and CEO of Northwell Health, the largest health care system in New York state. In this PSA, speaking as someone whose company has seen more COVID-19 patients than any other in the country, Dowling implores Americans to wear masks—not only for their own health, but for the health of those around them.
- The CDC reports that there have been close to 7.9 million cases of coronavirus reported in the United States since January. Around 216,000 people have died from the virus so far with hundreds more added to the tally every day. Several labs around the world are working on solutions, but there is currently no vaccine for COVID-19.
- The most basic thing that everyone can do to help slow the spread is to practice social distancing, wash your hands, and to wear a mask. The CDC recommends that everyone ages two and up wear a mask that is two or more layers of material and that covers the nose, mouth, and chin. Gaiters and face shields have been shown to be less effective at blocking droplets. Homemade face coverings are acceptable, but wearers should make sure they are constructed out of the proper materials and that they are washed between uses. Wearing a mask is the most important thing you can do to save lives in your community.
Two massive clouds of dust in orbit around the Earth have been discussed for years and finally proven to exist.
- Hungarian astronomers have proven the existence of two "pseudo-satellites" in orbit around the earth.
- These dust clouds were first discovered in the sixties, but are so difficult to spot that scientists have debated their existence since then.
- The findings may be used to decide where to put satellites in the future and will have to be considered when interplanetary space missions are undertaken.
What are they?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xODgyMDA0NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNTM1ODc0Mn0.NH33LuauIo__sUBi4tvhwxDcsvhflDFD-Nhx9FjlSNk/img.jpg?width=1245&coordinates=148%2C0%2C149%2C0&height=700" id="cec96" class="rm-shortcode" data-rm-shortcode-id="acb78abe2ab46a17e419ad30906751d6" data-rm-shortcode-name="rebelmouse-image" />
Artist's impression of the Kordylewski cloud in the night sky (with its brightness greatly enhanced) at the time of the observations.
G. Horváth<p>The<a href="https://en.wikipedia.org/wiki/Kordylewski_cloud" target="_blank"> Kordylewski clouds</a> are two dust clouds first observed by Polish astronomer Kazimierz Kordylewski in 1961. They are situated at two of the <a href="https://www.space.com/30302-lagrange-points.html" target="_blank">Lagrange points</a> in Earth's orbit. These points are locations where the gravity of two objects, such as the Earth and the Moon or a planet and the Sun, equals the centripetal required to orbit the objects while staying in the same relative position. There are five of these spots between the Earth and Moon. The clouds rest at what are called points four and five, forming a triangle with the clouds and the Earth at the three corners.</p><p>The clouds are enormous, taking up the same space in the night sky as twenty lunar discs; covering an area of 45,000 miles. They are roughly 250,000 miles away, about the same distance from us as the Moon. They are entirely comprised of specks of dust which reflect the light of the sun so faintly most astronomers that looked for them were unable to see them at all. </p><p>The clouds themselves are probably ancient, but the model that the scientists created to learn about them suggests that the individual dust particles that comprise them can be blown away by solar wind and replaced by the dust from other cosmic sources like comet tails. This means that the clouds hardly move but are <a href="https://www.nationalgeographic.com/science/2018/11/news-earth-moon-dust-clouds-satellites-planets-space/" target="_blank">eternally changing</a>. </p>
How did they discover this?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xODgyMDAzNi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1Nzc4MjQ4MX0.7uU9OqmQcWw5Ll1UXAav0PCu4nTg-GdJdAWADHanC7c/img.jpg?width=1245&coordinates=0%2C180%2C0%2C181&height=700" id="952fb" class="rm-shortcode" data-rm-shortcode-id="a778280a20f1c54cd2c14c8313224be2" data-rm-shortcode-name="rebelmouse-image" />
"In this picture the central region of the Kordylewski dust cloud is visible (bright red pixels). The straight tilted lines are traces of satellites."
J. Slíz-Balogh<p>In their study published in the <a href="https://academic.oup.com/mnras" target="_blank">Monthly Notices of the Royal Astronomical Society</a>, Hungarian astronomers Judit Slíz-Balogh, András Barta, and Gábor Horváth described how they were able to find the dust clouds using polarized lenses.</p><p>Since the clouds were expected to polarize the light that bounces off of them, by configuring the telescopes to look for this kind of light the clouds were much easier to spot. What the scientists observed, polarized light in patterns that extended outside the view of the telescope lens, was in line with the predictions of their mathematical model and ruled out other possible sources. </p>
Why are we just learning this now?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xODgyMDAzOS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2MjUyNDMyMH0.Zl8GmQ_rJHiL4b7hN0r_YBmgb6_ZqIRvqOVuko2ubpw/img.jpg?width=1245&coordinates=0%2C141%2C0%2C185&height=700" id="87afe" class="rm-shortcode" data-rm-shortcode-id="dd4c0b5088e601d7279cc5eb226f8b7b" data-rm-shortcode-name="rebelmouse-image" />
"Mosaic pattern of the angle of polarization around the L5 point (white dot) of the Earth-Moon system. The five rectangular windows correspond to the imaging telescope with which the patterns of the Kordylewski cloud were measured."
J. Slíz-Balogh<p>The objects, being dust clouds, are very faint and hard to see. While Kordylewski observed them in 1961, other astronomers have looked there and given mixed reports over the following decades. This discouraged many astronomers from joining the search, as study co-author Judit Slíz-Balogh <a href="https://ras.ac.uk/news-and-press/research-highlights/earths-dust-cloud-satellites-confirmed" target="_blank">explained</a>, <em>"The Kordylewski clouds are two of the toughest objects to find, and though they are as close to Earth as the Moon are largely overlooked by researchers in astronomy. It is intriguing to confirm that our planet has dusty pseudo-satellites in orbit alongside our lunar neighbor."</em></p>
Will this have any impact on space travel?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="c3d797fff5430c64afcb5a49bddc3616"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/Ou8N3v9SFPE?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Lagrange points have been put forward as excellent locations for a space station or satellites like the <a href="https://jwst.nasa.gov/about.html" target="_blank">James Webb Telescope</a> to be put into orbit, as they would require little fuel to stay in place. Knowing about a massive dust cloud that could damage sensitive equipment already being there could save money and lives in the future. While we only know about the clouds at Lagrange points four and five right now, the study's authors suggest there could be more at the other points.</p><p>While the discovery of a couple of dust clouds might not seem all that impressive, it is the result of a half-century of astronomical and mathematical work and reminds us that wonders are still hidden in our cosmic backyard. While you might never need to worry about these clouds again, there is nothing wrong with looking at the sky with wonder at the strange and fantastic things we can discover. </p>
New cancer-scanning technology reveals a previously unknown detail of human anatomy.
- Scientists using new scanning technology and hunting for prostate tumors get a surprise.
- Behind the nasopharynx is a set of salivary glands that no one knew about.
- Finding the glands may allow for more complication-free radiation therapies.
PSMA PET/CT technology<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="676e611b970c9b516cace0870447b325"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/RHAyoQF09X4?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>PSMA PET/CT is a new combination of <a href="https://www.mayoclinic.org/tests-procedures/pet-scan/about/pac-20385078" target="_blank">PET scans</a> and <a href="https://www.mayoclinic.org/tests-procedures/ct-scan/about/pac-20393675" target="_blank">CT scans</a> that is believed to offer a more reliable means of locating prostate cancer metastasis. A <a href="https://www.cancer.gov/news-events/cancer-currents-blog/2020/prostate-cancer-psma-pet-ct-metastasis" target="_blank" rel="noopener noreferrer">study</a> published last spring suggests it may be the most accurate way to diagnose prostate cancer metastasis than any method previously available.</p><p>Prior to PSMA PET/CT, the primary way to look for metastatic prostate cancer was to image the body using x-ray-based CT scans and to perform bone scans, since bone is where prostate cancer often spreads. CT scans, however, often miss small tumors, and bone scans can generate false positives as a result of other damage or abnormalities that have nothing to do with prostate cancer.</p><p>PSMA PET/CT scans track the travels of an intravenously administered radioactive glucose tracer throughout the body. For hunting down prostate cancer, this tracer contains a molecule that binds to the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1472940/" target="_blank">PSMA</a> protein that's present in large amounts in prostate tumors. The molecule is linked to a radioisotope, <a href="https://netrf.org/2018/11/13/gallium-68-scan-for-neuroendocrine-tumors/" target="_blank" rel="noopener noreferrer">gallium-68</a> (Ga-68).</p><p>In last spring's research, PSAM PET/CT was shown to be 27 percent more accurate than previous methods at finding metastases (92 percent accuracy as opposed to 65 percent). In addition, it was found to be much less likely to produce false positives, and it was particularly good at detecting tumors far removed from the prostate.</p>
A good kind of avoidance behavior<p>"Radiation therapy can damage the salivary glands," says Vogel, "which may lead to complications. Patients may have trouble eating, swallowing, or speaking, which can be a real burden."</p><p>The researchers looked back through the cases of 723 patients who had undergone radiation treatment, interested in seeing if inadvertent radiation of the tubarial glands was associated with the complications experienced by the patients. It turned out that this <em>was</em> the case: In cases where more radiation had been delivered to this area, patients did indeed report more in the way of complications of the type one would expect when salivary glands are radiated.</p><p>Now that we know the tubarial salivary glands exist, therapists can stay out of their way. Vogel says, "For most patients, it should technically be possible to avoid delivering radiation to this newly discovered location of the salivary gland system in the same way we try to spare known glands."</p><p>He's hopeful that that things may be about to get at least a bit better for cancer patients: "Our next step is to find out how we can best spare these new glands and in which patients. If we can do this, patients may experience less side effects which will benefit their overall quality of life after treatment."</p>
A new survey found that 27 percent of millennials are saving more money due to the pandemic, but most can't stay within their budgets.