Tag: Oxygen

Aliens? Or Alien Impostors? Finding Oxygen Might Not Mean Life

In our quest for life beyond the Solar System, it makes sense to look for a world like our own.

We’ve long hoped to find an Earth-sized world around a Sun-like star at the right distance for liquid water as our first step, and with thousands of planets in our coffers already, we’re extremely close.

But not every world with the right physical properties is going to have life; we need additional information to know whether a potentially habitable world is actually inhabited.

The follow-up would be to analyze the planet’s atmosphere for Earth-like signatures: potential signs of life.

Earth’s combination of atmospheric gases — nitrogen, oxygen, water vapor, carbon dioxide and more — has been assumed to be a dead giveaway for a planet with life on it.

But a new study by planetary scientist Dr. Sarah Hörst’s team throws that into doubt. Even worlds rich in oxygen might not harbor aliens, but an impostor process that could fool us all.

The scientific story of how to even reach that point is fascinating, and closer to becoming a reality than ever before.

We can understand how this happens by imagining we were aliens, looking at our Sun from a large distance away, trying to determine if it possessed an inhabited world.




By measuring the slight variations in the frequency of the Sun’s light over long periods of time, we’d be able to deduce the gravitational influence of the planets on them.

This detection method is known either the radial velocity or the stellar wobble method, and can tell us information about a planet’s mass and orbital period.

Most of the early (pre-Kepler) exoplanets were discovered with this technique, and it’s still the best method we have for both determining planetary masses and confirming the existence of candidate exoplanets.

We also need to know the size of the planet. With the stellar wobble alone, we’ll only know what the mass of the world is relative to the angle-of-inclination of its orbit.

A world that’s the mass of Earth could be well-suited to life if it’s got an Earth-like atmosphere, but it could be disastrous for life if it’s an iron-like world with no atmosphere at all, or a low-density, puffy world with a large gaseous envelope.

Most of the planets we know of that are comparable to Earth in size have been found around cooler, smaller stars than the Sun. This makes sense with the limits of our instruments; these systems have larger planet-to-star size ratios than our Earth does with respect to the Sun.

Most of them orbit red dwarf stars — the most common class of star in the Universe — which means the forces should tidally lock them: the same side should always face the star. These stars flare often, posing a danger to any potential atmospheres on these worlds.

Historically, when we’ve looked to the skies for evidence of life beyond Earth, we’ve been biased by hope and what we know on Earth.

Theories of dinosaurs on Venus or canals on Mars still linger in our memories, and we must be careful that extraterrestial oxygen signatures don’t lead us to falsely optimistic conclusions.

We now know that both abiotic processes and life-dependent ones can create an oxygen-rich atmosphere.

The hard problem, then, will be disentangling the potential causes when we actually find our first oxygen-rich, Earth-like exoplanet.

Our reward, if we’re successful, will be the knowledge of whether or not we’ve actually found life around another star.

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This Lung-Like Device Can Transform Water Into a Clean Source of Fuel

A device inspired by human lungs can split water into oxygen and hydrogen

Get water in your lungs, and you’re in for a very bad time.

But when water enters a new type of “lung” created by researchers at Stanford University, the result is hydrogen fuel — a clean source of energy that could one day power everything from our cars to our smartphones.

Though this isn’t the first device to produce hydrogen fuel, the unique design could be the first step along the path to an efficient method of generating hydrogen fuel.




Looking to Nature

The Stanford team describes its device in a paper published on Thursday in the journal Joule.

When air enters a human lung, it passes through a thin membrane. This membrane extracts the oxygen from the air and send it into the bloodstream. The unique structure of the organ makes this gas exchange highly efficient.

Combine hydrogen with oxygen, and you get electricity — and unlike the burning of fossil fuels, the only byproduct is water.

For that reason, researchers have been looking into hydrogen fuel for decades, but they simply haven’t found a way to produce it that is efficient enough to be worthwhile.

This is mainly because hydrogen doesn’t often exist on its own in nature — we need to isolate it, often by separating water into hydrogen and oxygen.

Take a Breath

The Stanford researchers’ lung is essentially a pouch created out of a thick plastic film. Tiny water-repelling pores cover the exterior of the pouch, while gold and platinum nanoparticles line its interior.

By placing the pouch in water and applying voltage, the researchers were able to compel the device to create energy at an efficiency 32 percent higher than if they laid the film flat.

They claim this is because the lung-like shape did a better job than other fuel cell designs of minimizing the bubbles that can form — and hurt efficiency — during the energy-generation process.

The geometry is important,” Stanford research Yi Cui said.

The team will now focus on scaling-up its design and finding a way to get it to tolerate higher temperatures — right now, it doesn’t work above 100 degrees Celsius, which could be a problem for commercial applications.

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NASA Is Planning To Make Water And Oxygen On The Moon And Mars By 2020

NASA astronaut Kate Rubins works with a Nitrogen/Oxygen Recharge System tank aboard the International Space Station.

NASA is forging ahead with plans to make water, oxygen, and hydrogen on the surface of the Moon and Mars.

If we ever want to colonize other planets, it is vital that we find a way of extracting these vital gases and liquids from moons and planets, rather than transporting them from Earth.

The current plan is to land a rover on the Moon in 2018 that will try to extract hydrogen, water, and oxygen — and then hopefully, Curiosity’s successor will try to convert the carbon dioxide in the atmosphere into oxygen in 2020 when it lands on Mars.

In 2018, NASA hopes to put a rover on the Moon that will carry the RESOLVE (Regolith and Environment Science and Oxygen & Lunar Volatile Extraction) science payload.

RESOLVE will contain the various tools necessary to carry out in-situ resource utilization (ISRU).




Basically, RESOLVE will sift through the Moon’s regolith (loose surface soil) and heat them up, looking for traces of hydrogen and oxygen, which can then be combined to make water.

There is also some evidence that there’s water ice on the surface of the Moon — RESOLVE will find out for certain by heating the soil and seeing of water vapor emerges.

A similar payload would be attached to Curiosity’s successor, which is currently being specced out by NASA and will hopefully launch in 2020.

This second IRSU experiment will probably suck in carbon dioxide from the Martian atmosphere, filter out the dust, and then process the CO2 into oxygen.

If either tech demonstration works as planned, future missions might include large-scale ISRU devices that are capable of producing significant amounts of hydrogen, oxygen, and water on the Moon or Mars.

This would probably be the most important advance since we first landed on the Moon in the ’60s. Basically, as it stands, space travel needs lots of hydrogen and oxygen and water.

Water has the unfortunate characteristic of being both heavy and incompressible, meaning it’s very difficult and expensive to lift large amounts of it into space (gravity can be really annoying sometimes).

Likewise, unless we come up with some other way of powering our spacecraft, it’s infeasible to carry the rocket fuel that we’d need for exploration from Earth.

In short, if we want to colonize space, we really, really need some kind of base outside of the Earth’s atmosphere, preferably on the Moon — but Mars would be good, too.

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Sea Spiders Pump Oxygen With Their Guts, Not Hearts

sea spider

Most animals depend on a beating heart to pump blood and oxygen, but sea spiders do this mostly with their unusual guts, according to a new study.

“Unlike us, with our centrally located guts that are all confined to a single body cavity, the guts of sea spiders branch multiple times and sections of gut tube go down to the end of every leg,” lead author H. Arthur Woods of the University of Montana, Missoula, said in a statement.

The study, published in the U.S. journal Current Biology, found that sea spiders, which take in oxygen directly through their cuticles, use gut peristalsis to move fluids.




In fact, the human gut also uses peristalsis – waves of involuntary constriction and relaxation of muscles — to mix gut contents and move them along.

Scientists had long observed that polar species, including giant sea spiders, have larger bodies than their more temperate or tropical relatives.

One of the things that make sea spiders a great organism for study is “that they are really skinny and, using a microscope, you can see easily into their bodies,” Woods said.

sea spider

In contrast, he noticed, their guts showed very strong and organized waves of peristaltic contractions, which are much more vigorous than would be needed for digestion.

It’s not clear whether the sea spiders’ space-filling guts first arose for purely digestive functions and the respiratory benefits came later or vice versa, the study said.

“Respiratory gut peristalsis may be more widespread than previously recognized,” the researchers wrote in their paper.

Although (sea spiders) are unusual in having gut diverticula in almost all body spaces, partially space-filling guts are common in other arthropods, suggesting that guts could transport gases in these other groups.”

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NASA Plans To Use Bacteria And Algae To Make Oxygen On Mars

If humans land on Mars in the 2030s as planned, one thing that will be essential to their survival will be self-sufficiency, as they won’t be able to take too much cargo with them.

With this in mind Nasa is testing whether oxygen can be created from Martian soil, without having to carry it all the way from Earth.

The innovative method would see bacteria or algae use the soil as fuel, pumping out usable oxygen in the process for astronauts on the surface.

Nasa has been working with Techshot Inc of Greenville, Indiana to develop this method in a so-called ‘Mars room’, which mimics the conditions on the red planet.




It is able to simulate the atmospheric pressure on the planet, in addition to the day-night temperature changes and the solar radiation that hits the surface.

In experiments, certain organisms were capable of producing oxygen from Martian soil – known as regolith – and they also removed nitrogen from it.

This is a possible way to support a human mission to Mars, producing oxygen without having to send heavy gas canisters,” said Eugene Boland, chief scientist at Techshot.

The research is part of the Nasa Innovative Advanced Concepts (NIAC) Programme.

It’s envisioned that biodomes could be scattered across the surface to produce the oxygen needed for humans to survive.

The oxygen produced could also be stored for later use.

But while experiments on Earth are all well and good, the scientists want to test their method actually on Mars in the near future.

To do so, an upcoming rover – such as the 2020 Mars rover – could carry small container-like devices with Earth organisms inside.

The containers would be buried a few inches underground in certain locations, to see how successful they are at producing oxygen.

Sensors inside the container would detect how much oxygen was made, and report the findings back to a satellite in Mars orbit.

The scientists note that the container would be sealed tightly, to prevent the organisms being exposed to – and possibly contaminating – the Martian surface.

But if proven successful, future explorers on Mars may use multiple biodomes like this to produce the oxygen they need to survive.

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Pass it on: New Scientist

Climate Change May Shrink the Fishes In The World

Warming temperatures and loss of oxygen in the sea will shrink hundreds of fish species—from tunas and groupers to salmon, thresher sharks, haddock and cod—even more than previously thought, a new study concludes.

Because warmer seas speed up their metabolisms, fish, squid and other water-breathing creatures will need to draw more oxyen from the ocean. At the same time, warming seas are already reducing the availability of oxygen in many parts of the sea.

A pair of University of British Columbia scientists argue that since the bodies of fish grow faster than their gills, these animals eventually will reach a point where they can’t get enough oxygen to sustain normal growth.

What we found was that the body size of fish decreases by 20 to 30 perent for every 1 degree Celsius increase in water temperature,” says author William Cheung, director of science for the university’s Nippon Foundation—Nereus Program.

These changes, the scientists say, will have a profound impact on many marine food webs, upending predator-prey relationships in ways that are hard to predict.




“Lab experiments have shown that it’s always the large species that will become stressed first,” says lead author Daniel Pauly, a professor at the university’s Institute for the Ocean and Fisheries, and principal investigator for the Sea Around Us.

Small species have an advantage, respiration-wise.

Still, while many scientists applaud the discovery, not all agree that Pauly’s and Cheung’s work supports their dramatic findings. The study was published today in the journal Global Change Biology.

Pauly is perhaps best known for his global, sometimes controversial, studies of overfishing.

But since his dissertation in the 1970s, he has researched and promoted a principle that suggests fish size is limited by the growth capacity of gills.

Based on this theory, he, Cheung and other authors published research in 2013 that showed average body weight for some 600 species of ocean fish could shrink 14-24 percent by 2050 under climate change.

It’s a difficult concept for people to imagine because we breathe air,” Pauly says. “Our problem is getting enough food—not oxygen. But for fish, it’s very different. For humans, it would be like trying to breathe through a straw.

Other scientists have linked oxygen to smaller fish sizes. In the North Sea, for example, haddock, whiting, herring and sole have already seen significant loss in size in areas of the sea with less oxygen.

Still, Pauly’s and Cheung’s 2013 results were criticized in some corners as overly simplistic. Earlier this year, a group of European physiologists argued that Pauly’s basic premise about gill size was, itself, flawed.

So Pauly and Cheung used more sophisticated models and re-examined their theory.

The new paper doubles down on their earlier case, explains the gill theory in more detail and argues that it can and should be used as a guiding principle.

The new work goes on to suggests their original conclusions actually underestimated the scale of the problem fish will soon face.

The earlier paper, for example, suggested the size of some species, such as tuna, may be less affected by climate change.

But the new research states that fast-swimming ever-mobile tunas, which already consume significant oxygen, may be more susceptible than some other fish.

In fact, in parts of the tropical Atlantic, Cheung says, there is a vast region where oxygen is already low in the open ocean. Other studies have shown tunas altering their range to avoid that bad water.

Tunas’ distributions have followed very closely the bounds of these oxygen minimum zones,” Cheung says.

Some fish experts find Pauly’s and Cheung’s gill theory and new work convincing.

Jeppe Kolding, a biology professor at the University of Bergen in Norway, who studies fish in Africa, says Pauly’s gill concept is the only thing he’s found that elucidates the dwarfing he’s seen in Nile tilapia, guppies, and a type of sardine found in Zambia and in Lake Victoria.

It does explain the phenomena I have encountered in Africa,” he says.

Nick Dulvy, a marine biologist at Simon Fraser University, says his own research “tends to confirm” Pauly’s ideas.

It is absoutely an inevitability that as fish grow heavier they will eventually reach a point where oxygen intake does not match their metabolic demand.

Still, one of Pauly’s earlier critics, Sjannie Lefevre, a physiologist with the University of Oslo in Norway, lead author of the critique published earlier this year in the same journal, continues to find Pauly’s gill theory wanting.

I am not at all impressed or convinced by their attempt to refute our arguments,” Lefevre says, adding that she doesn’t “consider the new results any more reliable.”

She says fish absolutely are capable of growing larger gills. “There are no geometric constraints stopping gills from growing as fast as the body of a fish,” she says.

She and Poertner could not view the work more differently. Lefevre says she hopes ecologists and modelers keep “an open and cautious mind” before accepting such unifying theories.

Poertner, on the other hand, maintains that Pauly’s and Cheung’s work is a great example of the right way to apply such theories.

The new research shows how “careful use of an overarching principle in a wide set of observations across species can support insight that is difficult to reach otherwise,” he says.

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