Nautilus Magazine: We Never Know Exactly Where We’re Going in Outer Space

In the early 1960s, during the space race, neither American nor Soviet scientists really knew where planets like Mars or Venus were—especially at the accuracy and precision essential for spacecraft navigation. That may sound faintly ludicrous. They of course knew roughly where a target like Venus would be when a spacecraft got there. But “roughly” in this context might be an offset of 10,000 or 100,000 kilometers. Planetary positions, their ephemerides, rely on the calibration of their orbits to extremely high precision over time. But the only way to do that properly is to make direct measurements, just as the mariners of old would need to sail right by an island or shoreline in order to nail down its latitude and longitude. [...]

It remains to be seen whether tiny spacecraft can carry the requisite computational toolkit or sensory and steering capacity to do this. The bright stars themselves might be the best markers to exploit, together with our own sun forming a navigational beacon. Tiny pulses from miniature laser diodes could provide thrust to maneuver with, and perhaps the key is to send hundreds, even thousands, of nanocraft, each with modest AI and an ability to learn from each other and to reach their goals in space and time through massive redundancy and the sacrifice of many. But when you’re trying to catch a flying bullet—whether star or planet—with another flying bullet, things can go wrong. [...]

In sending machines to other worlds, even to other stars, we have no choice but to fully admit our inaccuracies and imprecisions, to be entirely, brutally honest about our limited grasp of what’s out there. Even the laws of nature are deductions based on wholly imperfect measurements, whether of planetary orbits and gravity, or of the properties of logic and symbolic manipulation in algebra—the latter being “measured” through human minds and the machines those minds produce. The amazing thing is how well these laws let us model and predict aspects of the physical world, a capacity that has reassured and helped us for thousands of years. We have managed to turn the problem around, and can now predict the kinds of chaos that should occur across nature, from unsettled weather conditions and unstable stock markets to, of course, planets.

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Aeon: Imagine alien signals are detected. Here’s what happens next

Planets aren’t rare. Life is surprisingly durable. The more we’ve learned about the Universe, the more the search for extraterrestrial life has shifted from science fiction to serious scientific undertaking. So it’s worth considering how humanity would react if we learned, through some distant but unmistakable signal, that lifeforms elsewhere in the Universe were communicating with us. In this interview, Seth Shostak, senior astronomer at the Center for SETI Research in California, discusses how first contact is more likely to be perspective-shifting than Earth-shattering.

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Nautilus Magazine: Galactic Settlement and the Fermi Paradox

In a 2014 paper on the topic, my colleagues and I rebutted many of these claims. In particular, we argued that one should not conflate the population growth in a single settlement with that of all settlements. There is no reason to suppose that population growth, resource depletion, or overcrowding drives the creation of new settlements, or that a small, sustainable settlement would never launch a new settlement ship. One can easily imagine a rapidly expanding network of small sustainable settlements (indeed, the first human migrations across the globe likely looked a lot like this). [...]

The results are pretty neat. When we let the settlements behave independently, Hart’s argument looks pretty good, even when the settlement fronts are slow. Even if all the ships have a very limited range (only able to reach, say, the nearest stars to Earth) and even if they are no faster than our own interstellar ships today (like Voyager 2), we find they can still settle the entire Milky Way in less than its lifetime, supporting Hart’s version of the Fermi Paradox. [...]

On the other hand, there are a lot of assumptions in Hart’s arguments that might not hold. In particular, his assertion that if the sun has ever been in range of a settled system then it would have been settled and the settlers would still be here. Perhaps Earth life for some reason keeps the settlements at bay, either because “they” want to keep Earth life pristine or it’s just too resilient and pernicious for an alien settlement to survive. Perhaps Earth is Aurora?

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VICE: NASA’s Solar Probe Found Things Near the Sun That We Can’t Explain

During its two encounters, Parker traveled within 15 million miles of the Sun’s surface, far surpassing the 25-million-mile record first set by NASA’s Helios 2 mission in 1976. Parker has also claimed the title of the fastest human-made object in history from Helios 2, as it surfed near the Sun at over 153,000 miles per hour. [...]

“To our big surprise,” Kasper said, “by the time we got to our closest approach, [the solar wind] was flowing between 35 and 50 kilometers per second around the Sun. That’s something like 15 to 25 times faster than the standard solar models predict, so we’re missing something really fundamental in our standard models of the Sun—how it rotates and how the wind escapes—and that’s really interesting.” [...]

Though the mechanism behind these waves is still unknown, the sheer force of them may help explain two of the most persistent mysteries about the Sun: Why is solar corona, or the atmosphere of the Sun, about 1,000 times hotter than its surface? And why does the solar wind suddenly accelerate to supersonic speeds at a certain distance from the Sun?

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Nautilus Magazine:

Several things. People have long wondered, why has the Great Red Spot been around for such a long time? The Great Red Spot is a storm, and we are used to storms on Earth. The average hurricane lasts a couple of weeks at most, and it has a definite mechanism for destruction: It either goes into cool water, which cuts off its fuel supply, or it goes over land, which really cuts off its fuel supply. Tornadoes are quite impressive, but they’re very ephemeral—they only last a few hours. So why do we have a Great Red Spot lasting so long? People used to say, “Oh, it’s clouds hanging around a mountain top.” Or “It’s an iceberg in a sea of hydrogen.” Those theories pretty much stopped around 1979, when Voyagers 1 and 2 flew by the planet. Nobody really knew it was a vortex, a huge hurricane that takes about six days for a single rotation. The United States would fit into the Red Spot a couple of hundred times. I mean, it’s really huge. One of the great things about the Voyager missions was that they took hundreds of pictures of the clouds that make up the Red Spot, so we could finally see the whole thing swirling around, and that’s how we knew for sure it was a vortex. Nobody knew it was really spinning. [...]

The harvest of that energy is what balances the loss of the Great Red Spot’s energy from thermal radiation. In a computer simulation, you can actually measure the direction and magnitude of all the energies that go in and out of the Great Red Spot, and the whole energy budget balances very nicely. You’ve got this great drain of potential energy in the atmosphere in the area surrounding the Great Red Spot due to this circulation of gas, but it’s OK because the sun re-establishes radiative equilibrium in that surrounding area and re-supplies its energy. So, ultimately, the source of energy that prevents the Great Red Spot from being destroyed is the sun. [...]

I am speculating that the Red Spot is, from top to bottom, somewhere between 50 and 70 kilometers tall. From side to side, it’s about 26,000 kilometers. So it’s a pancake. Just like with a tube of toothpaste, if I squish the pancake with high pressure at its center, something is going to squirt out the sides and top and bottom. It’s known that the Great Red Spot has a high pressure at its center, but its gases don’t go squirting out horizontally from its sides because of the Coriolis force in those directions—instead they squirt out vertically from the top and bottom. So, what can prevent the gases from squirting out vertically? The only way that I know to prevent that is if the top of the Great Red Spot has a dense cold lid of atmosphere above it. It’s that extra density that pushes the gases in the Great Red Spot back down. And, below the Great Red Spot, there must be a warm buoyant floor of atmosphere, and that floor prevents the high pressure center from pushing the gases in the Great Red Spot downward and out its bottom. That’s the balance.

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National Geographic: Mysterious oxygen spike seen on Mars puzzles scientists

In the Martian spring and summer, the red planet’s oxygen levels spike an extra 400 parts per million, or 30 percent above what researchers expected to see based on the behavior of other gases in the planet’s atmosphere. The oxygen spike seems to partially correlate to another gassy mystery: a seasonal ebb and flow of atmospheric methane on Mars. [...]

Though it’s tempting to think of photosynthesis when hearing about oxygen in a planet’s atmosphere, non-living processes are known to make oxygen on Mars, and these findings are not necessarily evidence of life. Instead, the results highlight gaps in our understanding of the red planet’s surface chemistry—holes that must be filled if we are to hunt for direct evidence of past or present Martians.[...]

Future missions might be able to help, especially if they can take more atmospheric measurements. Because of the many science demands on Curiosity, Trainer’s team obtained only 19 data points across the Martian seasons. While this gives them a sense of the long-term pattern, they can’t see any shorter-term changes. What would researchers find if they could take daily, or even hourly, oxygen and methane readings from Mars?

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The Atlantic: An Alarming Discovery in an Astronaut’s Bloodstream

The study was designed to study different, well-known side effects of space travel. A decade ago, scientists started noticing that astronauts who spent months on the International Space Station came home with swollen optic nerves, slightly flattened eyeballs, and changes in vision. NASA started putting glasses on board the station for astronauts who found that their eyesight had worsened. Scientists have suspected that the cause involves an accumulation of the body’s fluids such as blood and water. Free from the steady tug of gravity, the fluids float toward the head and can increase pressure inside the skull. [...]

Scans showed that blood flow in the vein stalled in five of the 11 astronauts. “Sometimes it was sloshing back and forth a bit, but there was no net-forward movement,” Marshall-Goebel says. Seeing stagnant blood flow in this kind of vein is rare, she says; the condition usually occurs in the legs, such as when people sit still for hours on a plane. The finding was concerning. Stagnant blood, whether it’s in the neck or in the legs, can clot. Blood clots can dissolve on their own or with the help of anticoagulants, but the blockages can also cause serious problems, such as lung damage. [...]

The researchers attribute the effects they observed to the space environment. All the astronauts were considered to be in good health before they launched. And when they came home, the conditions vanished in nearly all of them. When the researchers analyzed the data, they found that a second astronaut may have developed a blood clot no one had seen while they were in orbit. But no one experienced any health troubles. “None of the crew members actually had any negative clinical outcomes,” Marshall-Goebel says.

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Nautilus Magazine: Is Physical Law an Alien Intelligence?

For example, if machines continue to grow exponentially in speed and sophistication, they will one day be able to decode the staggering complexity of the living world, from its atoms and molecules all the way up to entire planetary biomes. Presumably life doesn’t have to be made of atoms and molecules, but could be assembled from any set of building blocks with the requisite complexity. If so, a civilization could then transcribe itself and its entire physical realm into new forms. Indeed, perhaps our universe is one of the new forms into which some other civilization transcribed its world.[...]

For example, only about 5 percent of the mass-energy of the universe consists of ordinary matter: the protons, neutrons, and electrons that we’re composed of. A much larger 27 percent is thought to be unseen, still mysterious stuff. Astronomical evidence for this dark, gravitating matter is convincing, albeit still not without question. Vast halos of dark matter seem to lurk around galaxies, providing mass that helps hold things together via gravity. On even larger scales, the web-like topography traced by luminous gas and stars also hints at unseen mass. [...]

The universe does other funky and unexpected stuff. Notably, it began to expand at an accelerated rate about 5 billion years ago. This acceleration is conventionally chalked up to dark energy. But cosmologists don’t know why the cosmic acceleration began when it did. In fact, one explanation with a modicum of traction is that the timing has to do with life—an anthropic argument. The dark energy didn’t become significant until enough time had gone by for life to take hold on Earth. For many cosmologists, that means our universe must be part of a vast multiverse where the strength of dark energy varies from place to place. We live in one of the places suitable for life like us. Elsewhere, dark energy is stronger and blows the universe apart too quickly for cosmic structures to form and life to take root.

But perhaps there is another reason for the timing coincidence: that dark energy is related to the activities of living things. After all, any very early life in the universe would have already experienced 8 billion years of evolutionary time by the time expansion began to accelerate. It’s a stretch, but maybe there’s something about life itself that affects the cosmos, or maybe those well-evolved denizens decided to tinker with the expansion.

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Politico: Germany wary of Macron’s space force

Macron unveiled the broad outlines of the plan during Bastille Day celebrations this month, saying it would help the country “better protect our satellites.”

But the French president's agenda, unveiled in the midst of France's biggest national celebration, sits uneasily with Germany's preference for a multilateral approach to military and defense issues. [...]

In his announcement, Macron was careful to say that the plans should fit with a “European framework” but he also said the move is meant to strengthen France's “strategic autonomy.”

And the president’s insistence that the country must launch an “active” defense of its array of space-based infrastructure — key to communication networks, as well as intelligence, navigation and surveillance — has raised questions over whether he wants to develop offensive capabilities that could be deployed by France alone. [...]

However, Brussels is for the first time launching a significant program to fund defense equipment spending, despite strong opposition from left-wing groups to the idea of using EU cash for military purposes.

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IFLScience: Astronomers Looked For Alien Civilization In Our Closest 1,300 Stars. Here's What They Found

“We scoured thousands of hours of observations of nearby stars, across billions of frequency channels. We found no evidence of artificial signals from beyond Earth, but this doesn't mean there isn't intelligent life out there: we may just not have looked in the right place yet, or peered deep enough to detect faint signals,” Dr Danny C Price, a radio astronomer who leads the Breakthrough Listen project, said in a statement. [...]

Founded in 2015, the Breakthrough Listen project was funded by Yuri Milner, Russia's answer to Peter Thiel, who founded the colossal Russian internet company "Mail.ru Group" and an investor in Facebook, Twitter, Airbnb, Whatsapp, and numerous other big names in tech. Stayed tuned because there's plenty more on its way.

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The Atlantic: A Tremor on Mars Confirms a Lasting Suspicion

Scientists know this because they sent a seismometer to our planetary neighbor. The instrument arrived last year, on board a NASA lander called InSight. The seismometer, small and dome-shaped, has sat on the brick-colored surface since, waiting for hints of movement below the surface. On April 6, it caught something, a “quiet but distinct” signal, scientists said. A rumble from the depths. [...]

Scientists have suspected for decades that they’d find this phenomenon if they had the right tools to look. Unlike Earth, Mars lacks tectonic plates that glide over its mantle, jostling the ground when they touch. But like Earth, Mars has three distinct layers—a rocky crust, a mantle, and a metal core—and it’s still cooling from its fiery formation out of a primordial cloud of cosmic dust. Even now, billions of years later, heat radiates from its center and can be strong enough to crack the surface and escape. The fracturing sends seismic waves streaming in all directions. [...]

While scientists are thrilled about the detection, they wish the rumble were stronger. The quake measured about 2.5 on the Richter scale, too weak to draw a path within the depths. If a tremor like that happened on Earth, you wouldn’t feel it. If you were standing next to the InSight lander at the moment of detection, you wouldn’t know either. “We are waiting for the big, big one,” says David Mimoun, a scientist at France’s Higher Institute of Aeronautics and Space and a member of the seismometer team. Researchers expect to detect dozens more, some as powerful as 5.5 magnitude.

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Kurzgesagt – In a Nutshell: The Most Dangerous Stuff in the Universe - Strange Stars Explained

Inside neutron stars we can find the weirdest and most dangerous substance in the universe: Strange matter. What is strange matter, how dangerous is it and what can it tell us about the origin of the universe?

The New Yorker: Have Aliens Found Us? A Harvard Astronomer on the Mysterious Interstellar Object ‘Oumuamua

Wait. The most unusual fact about it is that it deviates from an orbit that is shaped purely by the gravitational force of the sun. Usually, in the case of comets, such a deviation is caused by the evaporation of ice on the surface of the comet, creating gases that push the comet, like the rocket effect. That’s what comets show: a cometary tail of evaporated gas. We don’t see a cometary tail here, but, nevertheless, we see a deviation from the expected orbit. And that is the thing that triggered the paper. Once I realized that the object is moving differently than expected, then the question is what gives it the extra push. And, by the way, after our paper appeared, another paper came out with analysis that showed very tight limits on any carbon-based molecules in the vicinity of this object.[...]

The only thing that came to my mind is that maybe the light from the sun, as it bounces off its surface, gives it an extra push. It’s just like a wind bouncing off a sail on a sailboat. So we checked that and found that you need the thickness of the object to be less than a millimetre in order for that to work. If it is indeed less than a millimetre thick, if it is pushed by the sunlight, then it is maybe a light sail, and I could not think of any natural process that would make a light sail. It is much more likely that it is being made by artificial means, by a technological civilization.[...]

It’s possible that the civilization is not alive anymore, but it did send out a spacecraft. We ourselves sent out Voyager I and Voyager II. There could be a lot of equipment out there. The point is that this is the very first object we found from outside the solar system. It is very similar to when I walk on the beach with my daughter and look at the seashells that are swept ashore. Every now and then we find an object of artificial origin. And this could be a message in a bottle, and we should be open-minded. So we put this sentence in the paper.

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IFLScience: Where IS Everybody?

Probably one of the most fascinating possible solutions is actually older than the paradox itself. Russian astronautics pioneer Konstantin Tsiolkovsky implicitly mentioned the question in an unpublished manuscript. His solution is now known as the "zoo hypothesis". His theory suggests that alien civilizations exist, but they won’t contact us until we are ready to be contacted, leaving us to our own devices yet keeping an eye on us.

This idea clearly echoes in the minds of many when talking about UFOs. Many argue that alien sightings are just a way for these advanced civilizations to keep a non-too conspicuous eye on our planet. Many official investigations, such as Project Blue Book, have come to the conclusion that no UFOs were a threat to National Security – definitely in favor of the "good watchful aliens" idea. At the same time, the reports concluded there was no evidence that UFOs were actually extraterrestrials.

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Kurzgesagt – In a Nutshell: End of Space – Creating a Prison for Humanity

Space travel is the most exciting adventure for humanity, but in an irony of history we may stop ourselves from going into space the more we do it. With every rocket launched we are creating a deadly trap for mankind.

Nautilus Magazine: So Can We Terraform Mars or Not?

Musk, the CEO and lead designer of SpaceX, wants to “make life multiplanetary,” starting with Mars. The red planet is relatively close to the Earth and once harbored surface seas and rivers, and it still has ice and a subsurface lake. Its weather is surprisingly workable, too. Mars’ surface temperature range (–285 to 88 degrees Fahrenheit) isn’t too far off from Earth’s (–126 to 138 degrees Fahrenheit). The problem is Mars’ atmosphere now has 0.006 bar of pressure, where one bar is the standard atmospheric pressure at sea level on Earth. Not only does this mean that dangerous levels of radiation reach the surfaced unchecked, but humans need at least 0.063 bar to keep our bodily liquids from boiling (this is called the Armstrong limit). [...]

No—not any time soon. At least, that’s according to the latest look at the idea from NASA’s principal investigator for the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, Bruce Jakosky, a space scientist at the University of Colorado, Boulder. He says the growing popularity of terraforming—driven in part by Musk—persuaded him and Christopher Edwards, a geologist also at Boulder, to gauge whether it was feasible. Their answer: No, it “is not possible using present-day technology.” In their July Nature Astronomy paper, they mention Musk directly, shooting down his idea of terraforming by nuking Mars’ polar ice caps. The amount of frozen CO2 released would not be enough to induce a runaway greenhouse effect, they argue. On July 30, Discover magazine singled out Musk in a tweet linking to the headline: “Sorry, Elon. There’s Not Enough CO2 to Terraform Mars.” [...]

If Jakosky is wrong, and Mars really does have multiple bar-equivalent of buried CO2 that we can access, we could potentially terraform Mars rapidly. “To judge from how quickly our greenhouse emissions are warming Earth, we could shift Mars into a warm climate state within 100 years,” McKay explained in his Nautilus feature. “The most efficient technique would be to produce supergreenhouse gases such as chlorofluorocarbons or, better, perfluorinated compounds, which are not toxic, do not interfere with the development of an ozone layer, and resist destruction by solar ultraviolet radiation. Curiosity has recently confirmed the presence of fluorine in the rocks on Mars, so the ingredients are all there.”

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IFLScience: Scientists Have Discovered The Strongest Known Material In The Universe

Using simulations to study the elastic properties of neutron star crusts, the researchers were able to conclude that the material inside it is up to 10 billion billion times more rigid than steel. Neutron stars are, after all, 100 trillion times denser than any material here on Earth. The results are published in Physical Review Letters.

The simulations required 2 million hours worth of processor time, which was conducted using a supercomputer. On a regular laptop, the simulations would run for 250 years. [...]

"A lot of interesting physics is going on here under extreme conditions and so understanding the physical properties of a neutron star is a way for scientists to test their theories and models,” Caplan added. “With this result, many problems need to be revisited. How large a mountain can you build on a neutron star before the crust breaks and it collapses? What will it look like? And most importantly, how can astronomers observe it?"

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IFLScience: A Physicist Claims He's Figured Out Why We Haven't Met Aliens Yet, And It's Pretty Worrying

Russian physicist Alexander Berezin, from the National Research University of Electronic Technology (MIET), has another idea. He calls it the “First in, last out” solution of the Fermi Paradox. He suggests that once a civilization reaches the capabilities of spreading across the stars, it will inevitably wipe out all other civilizations. [...]

Berezin's solution for the paradox comes from several simplifications of assumptions. For example, our definition of life depends on seven parameters, but for Berezin, there’s only one that matters: growth. Growth is the push for expanding beyond the planet of origin, and if the push to expansion becomes the dominant force, it will trample any other existing life in the universe. Colonialism and capitalism are two historical example of such forces.

So, is this it? We need to either go out there and conquer or be destroyed? Well, Berezin hopes that he’s wrong. One other requirement of his solution is that life can only be found when very close rather than at a distance. So finding alien life before we are on the destruction path might just make us a decent civilization.

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The Atlantic: Mike Pence’s Outer-Space Gospel

This kind of language, the invocation of past conquests to promote future ones, persists to this day, and the current White House has described the aspirations of the American space program in similar terms. But it has added an extra layer to the rhetoric, courtesy of the vice president. Since the Trump administration was sworn in, Mike Pence has been the unofficial spokesperson for the U.S. space program, touring nasa centers and delivering remarks about the country’s ambitions on behalf of the president. Even now that nasa finally has an administrator—it took nearly 15 months after the inauguration to get a Donald Trump nominee into the job—Pence remains the headliner at space-related events. [...]

No leader before Pence has injected this much religious rhetoric into speeches about the space program, according to space historians. Which makes sense, since Pence is an Irish Catholic turned evangelical Christian, and outspokenly so. Pence has a long record of presenting his political beliefs in the context of his religious ones; even before he was elected to any office, Pence liked to say he was “a Christian, a conservative, and a Republican, in that order.” As a congressman, he cited scripture to explain his votes and prayed with his staffers. [...]

In his famous speech, Kennedy had asked for God’s blessing: “As we set sail, we ask God’s blessing on the most hazardous and dangerous and greatest adventure on which man has ever embarked.” Buzz Aldrin, who followed him, brought a small plastic container of wine and a piece of bread, and actually took Communion on the moon. The stunning success of the landing strengthened the notion that the United States was favored by God over other would-be spacefaring nations, Weibel says.

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Kurzgesagt – In a Nutshell: Wormholes Explained – Breaking Spacetime

Are wormholes real or are they just magic disguised as physics and maths? And if they are real how do they work and where can we find them?