Month: July 2021

For decades, scientists engaged in the search for life in the universe (also known as astrobiology) have focused on the search for life on other Earth-like planets. This included terrestrial (also known as rocky) planets outside of our solar system (extrasolar planets) and those at home. Beyond Earth, Mars is considered to be the most habitable planet alongside Earth, and scientists have also theorized that life (in microbial form) could exist in the cloud tops of Venus.

In all cases, a major focus is on whether planets have (or have had in the past) large bodies of water on their surface. However, a new study led by a team of British and German researchers (with support from NASA) has shown that the existence of life may have less to do with the amount of water than with the presence of atmospheric water molecules. As a result, we may be luckier to find life on the turbulent cloud deck of Jupiter than on that of Venus.

The study describing their results, recently published in Nature Astronomy under the title “Water Activity in the Uninhabitable Clouds of Venus and Other Planetary Atmospheres”, was written by Dr. John E. Hallsworth of the School of Biological Sciences at Queen’s University Belfast. He was supported by colleagues from several universities in the UK and Germany as well as the Space Science Division (SSD) of the NASA Ames Research Center.

This artistic impression shows Venus. Astronomers at MIT, Cardiff University, and elsewhere may have observed signs of life in Venus’ atmosphere. Credits: ESO (European Space Agency) / M. Grain Knife & NASA / JPL / Caltech

Venus has been the focus of attention lately since the announcement that phosphine gas was discovered in the planet’s dense atmosphere. These results, according to a team of independent researchers, were a possible sign that microbial life might exist in Venus’ sulfuric acid clouds (also known as a potential biosignature). However, according to this latest study, Venus’s atmosphere does not have enough water activity to support this claim.

This conclusion is based on a new method developed by Hallsworth and colleagues to determine the level of water activity in a planet’s atmosphere. They then applied this method to the atmosphere of Venus, where temperatures range from 30 to 80 ° C (86 to 176 ° F) at altitudes of 50 km (30 miles) above the surface and where water vapor makes up about 0.002% of the atmosphere’s volume .

Ultimately, the researchers found that the water activity in Venus’ atmosphere was more than a hundred times below the lower limit. When they used the same method on the clouds of Jupiter, they found something entirely different. Above the stratosphere-thermosphere boundary (320 km above the troposphere) there is a “sweet spot” where the temperatures are stable and the clouds have a sufficiently high water vapor concentration.

In short, the clouds of Venus don’t have what it takes, but the upper atmosphere of Jupiter does. This information is of great importance at a time when NASA and other space agencies are proposing various astrobiology missions for the near future. Before these missions can be sent out to search for life, it is imperative that we prioritize targets based on the likelihood of scientific return.

NASA / JPL-Caltech / SwRI / MSSS / Kevin M. Gill (wikimedia Commons)

Like Dr. Hallsworth stated in a press release from Queen’s University Belfast:

“Our research shows that the sulfuric acid clouds on Venus have too little water for active life to exist based on what we know about life on Earth. We also found that the water and temperature conditions in the Jupiter clouds could allow microbial life forms to persist, provided that other requirements such as nutrients are in place.

“This is a timely realization as NASA and the European Space Agency have just announced three missions to Venus in the coming years. One of them will take measurements of the Venusian atmosphere, which we can compare with our results. ”

In addition, the results of this study represent another possibility to broaden the search for habitable exoplanets. Currently, the characterization of exoplanets is focused on finding evidence of life on rocky planets with surface water. But the detection of sufficient water vapor in the atmosphere of gas giants – such as Exo-Jupiter and Exo-Neptune – could point the way to life beyond our solar system.

“We have also done calculations for Mars and Earth and show that these calculations can be done for planets outside of our solar system,” added Dr. Hallsworth added. “Although our research does not claim that extraterrestrial (microbial) life exists on other planets in our solar system, it does show that if water activity and other conditions are right, such life could exist in places we hadn’t looked for before. “

This artist’s impression shows the planet orbiting the sun-like star HD 85512 in the southern constellation Vela (The Sail). Photo credit: ESO

Dr. Christopher McKay, a planetary scientist at NASA Ames and another co-author of the study, brought his extensive expertise in planetary atmospheres and astrobiology to this research. “We infer water activity from atmospheres without any model, based only on direct observations of pressure, temperature and water concentration,” he said.

In the near future, the James Webb Space Telescope (JWST) will finally launch into space (currently planned for November 2021). With its advanced infrared imaging capabilities, the JWST will play an important role in astrobiology and the characterization of exoplanet atmospheres. Coupled with missions like the Nancy Grace Roman Space Telescope (RST), the count of potentially habitable exoplanets is expected to grow exponentially.

Dr. Philip Ball, expert on the physics and chemical biology of water and co-author of the article, said:

“The search for extraterrestrial life was sometimes a bit simplified when it came to water. As our work shows, it is not enough to say that liquid water equates to habitability. We also need to think about how earth-like organisms actually use it – which shows us that we then have to wonder how much of the water is actually available for these biological purposes. ”

Further reading: Queens University Belfast, Natural Astronomy

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[If I interpret this press release correctly, I believe it claims: Ocean plastic pollution is less than 1% of what we’ve been screaming for decades, but is still as big a problem as ever! MAYBE EVEN BIGGER!~cr]

The missing plastic sink in the ocean: away from the rivers

The mysterious plastic tub in the ocean

UNIVERSITY OF BARCELONA

Research news

PICTURE: A MICROPLASTIC UNDER THE MICROSCOPE. View more CREDIT: CEFREM / UPVD

Plastics are a growing problem for natural ecosystems around the world, and especially for our marine and freshwater environments. Rivers are the main source of plastic pollution as they are estimated to bring millions of tons of plastic into our oceans annually through poor land-based waste management. The problem is that estimates of plastic flowing out of rivers are tens to hundreds of times higher than the amount of plastic floating on the ocean’s surface. So where does all this plastic from rivers actually go – is there a plastic sink missing somewhere in the ocean? Are the estimates correct?

In an article published today in Science, Dr. Lisa Weiss and her colleagues from the Center of Education and Research on Mediterranean Environments (CEFREM), a joint research laboratory between the University of Perpignan (UPVD) and the French National Center for Scientific Research (CNRS), and a team of researchers from a number of research institutions in France and from the University of Barcelona in Spain show that current river river ratings are overestimated by two to three orders of magnitude compared to previous estimates. This would explain why a large amount of microplastic appears to be disappearing into a mysterious “plastic sink” in the ocean.

However, these results do not suggest that plastics are less of a problem than previously thought. In fact, through their analyzes, the researchers found that plastics remain on the ocean surface much longer than previously thought – which further exacerbates the effects of plastic pollution on natural systems.

The mysterious plastic tub in the ocean

Rivers are the main source of plastic discharges into the oceans. According to current estimates, the floating stocks of microplastics on the ocean surface – from ten to one hundred tons – are only a small fraction of the millions of tons that are emitted by rivers every year. This imbalance has led to the “plastic sink” hypothesis, according to which the amount of microplastic in the “plastic sink” plus the plastic on the surface would be equivalent to the amount that is believed to be discharged from rivers into the sea.

According to the study’s lead author, Dr. Lisa Weiss from the CEFREM laboratory at the University of Perpignan: “The in-situ data we now have for microplastics in rivers, compared to early empirical model studies, enabled us to put together a robust database that we were then able to analyze, to get a more reliable estimate of the amount of microplastic discharged from rivers into the sea. This process has revealed several significant methodological errors in previous flow estimates. When we corrected these errors, we found that the estimates of global river flow are two to three orders of magnitude lower than previously thought. In addition, we found that the average retention time of microplastics on the surface of the oceans can actually be a few years instead of just a few days as previously estimated. “

According to the study’s lead author, Dr. Lisa Weiss from the CEFREM laboratory at the University of Perpignan: “The in-situ data we now have for microplastics in rivers, compared to early empirical model studies, enabled us to put together a robust database that we were then able to analyze, to get a more reliable estimate of the amount of microplastic discharged from rivers into the sea. This process has revealed several significant methodological errors in previous flow estimates. When we corrected these errors, we found that the estimates of global river flow are two to three orders of magnitude lower than previously thought. In addition, we found that the average retention time of microplastics on the surface of the oceans can actually be a few years instead of just a few days as previously estimated. “

“We can now confirm that the search for the missing ‘plastic sink’ is over as the missing plastics were found by correcting the river flow estimate,” says Professor Miquel Canals, head of the Consolidated Research Group on Marine Geosciences at the University of Barcelona and one of them of the study co-authors.

The new study identifies key methodological errors that have led to inaccurate assessments of rivers and the total mass of microplastics discharged from rivers into the sea on a global scale. In particular, errors were made due to a systematic overestimation of the average microplastic particle weight in river samples; from the integration of incompatible data obtained through various sampling methods; and from ratings based on the relationship between microplastic flows and the MPW (Missmanaged Plastic Waste) index

.A fight without borders to preserve the oceans of our planet

Marine litter knows no borders and has reached the remotest corners of our oceans and seas. According to Dr. Wolfgang Ludwig, director of the CEFREM laboratory and co-author of the study, “will only have a chance of winning the fight against microplastic pollution if we target the sources in which microplastic waste is produced”. . We have to act on a human level. We have to change our consumption habits, manage our waste better and do this on a global basis. “

“Our study shows that marine microplastic pollution is not only coming from developing countries – with little to no waste management, as one might think – but also from countries with well-established waste management systems. If we were to stop microplastics from entering the sea from rivers today, the amount of suspended particles and their harmful effects on marine ecosystems would last at least several years, ”said Dr. Ludwig.

Next Steps…

The impact of plastics on the marine environment is an emerging area of ​​scientific research that has spawned a large number of scientific publications in recent years. Still, we are only just beginning to understand how plastics circulate in the oceans. There are many plastic size classes, oceanic compartments, and land-to-sea transfer processes that urgently require further research to properly assess inventory sizes and exchange flows between compartments. In the future, we will need the best science available if we are to have a chance to win the battle against plastic pollution. To do this, the scientific community must work together to overcome past inertia, correct mistakes, and work with common protocols and guidelines to provide the best possible decision-making support to protect our oceans and seas.

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From EurekAlert!

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Aim for the Center

The Milky Way is 13 BILLION years old. Some of our Galaxy’s oldest stars were born near the beginning of the Universe itself. During all these eons of time, we know at least one technological civilization has been born – US!

But if the Galaxy is so ancient, and we know it can create life, why haven’t we heard from anybody else? If another civilization was just 0.1% of the Galaxy’s age older than we are, they would be millions of years further along than us and presumably more advanced. If we are already on the cusp of sending life to other worlds, shouldn’t the Milky Way be teeming with alien ships and colonies by now?

Maybe. But it’s also possible that we’ve been looking in the wrong place. Recent computer simulations by Jason T. Wright et al suggest that the best place to look for ancient space-faring civilizations might be the core of the Galaxy, a relatively unexplored target in the search for extra terrestrial intelligence.

Animation showing the settlement of the galaxy. White points are unsettled stars, magenta spheres are settled stars, and white cubes represent a settlement ship in transit. The spiral structure formed is due to galactic shear as the settlement wave expands. Once the Galaxy’s center is reached, the rate of colonization increases dramatically. Credit: Wright et al

The Churn

Older mathematical models of space colonization have tried to determine the time required for a civilization to spread throughout the Milky Way. Given the size of the Milky Way, wide-scale galactic colonization could take longer than the age of the Galaxy itself. However, a unique feature of this new simulation is its accounting for the motion of the Galaxy’s stars. The Milky Way is not static, as assumed in prior models, rather it is a churning swirling mass. Colonization vessels or probes would be flying among stars that are themselves in motion. The new simulation reveals that stellar motion aids in colonization contributing a diffusing effect to the spread of a civilization.

The simulation is based previous research by Jonathan Carroll-Nellenback et al which proposed that a hypothetical civilization could spread at sub-light speeds through a moving Galaxy. The simulation assumes a civilization using ships travelling at velocities comparable to our own spacecraft (about 30km/s). When a ship arrives at a virtual habitable world in the simulation, the world is considered a colony and can itself launch another craft every 100,000 years if another uninhabited world is in range. Simulated space craft range is 10 light years with maximum travel duration of 300,000 years. Technology from a virtual colony was set to last 100 million years before dying out with the opportunity to be resettled should another colony drift into range by galactic motion.

The results are dramatic. The Galaxy’s rotation generates a wave or “front” of colonization. Once the front reaches the Galactic core, the core’s density catalyzes a rapid increase in the rate of colonization. Even with very conservative limits placed on the speed of the space craft, a majority of the Galaxy could be colonized in less than a billion years – a fraction of its total age.

Line of Sight

The simulation’s results reaffirm past proposals by Vishal Gajjar et al. to search the Galactic center for signs of life. Not only can the center of the Galaxy be rapidly colonized, but also efficiently scanned for technology. We have a direct line of sight to the Galaxy’s center which encompasses the densest region of space relative to us. And since the Galaxy formed from the inside out, the center is filled with older planets which provide more time for life to evolve.

The center also serves as a logical place to “talk” to and from – a central focal point of the Galaxy. If you wanted to get a signal out to the rest of the Galaxy, you could do so from the center to blanket the disk of the Milky Way. Likewise, if you wanted to find a signal, you might look to that same center. Gajjar et al. also hypothesize that an advanced civilization may be capable of tapping into the energy of the Milky Way’s central supermassive black hole to power a galaxy-wide signal beacon. Talk about a powerful “hello!”

A view toward the Galaxy’s Center from Earth captured in the Mojave Desert. Credit: Photo by Author

Then Why so Quiet?

Still, none of this answers the previous question – where are they? In fact, the speed at which the Galaxy could be colonized complicates why we haven’t heard from anybody. Furthermore, Caroll-Nellenback et al. also note that during colonization, an advanced civilization might develop new propulsion technologies shortening the time needed to spread. And yet, preliminary radio scans of the Galactic Core haven’t revealed any signals. Perhaps the silence itself is an answer. The Galaxy is so old with so much time available for life to spread that some believe the silence dooms any hope of meeting anybody.

But there is still hope! The simulation shows it’s possible that some parts of the Galaxy are never settled despite eons of time. It’s a matter of efficiency. Remember, you want to colonize at the shortest possible ranges. As time passes, some colonies die out and are lost perhaps from resource exhaustion or cataclysmic event. Rather than reach farther out into space, colonies choose to reinhabit a dead colony at closer range. Clusters of inhabited colonies form surrounded by uninhabited planets that are never colonized . A “steady state” is achieved where regions of the Milky Way’s habitable worlds are simply too inefficient to colonize.

There are other possibilities to explain the silence as well. Perhaps long-lived civilizations are governed by sustainability to grow more slowly than anticipated. If there are multiple colonizing civilizations perhaps they are competing for resources or keep a distance from eachother. Perhaps civilizations take care to not interfere with inhabited planets such as ours (similar to the Prime Directive in Star Trek) or are cautious of potential biological incompatibilities faced on other worlds. All these possibilities may explain why we have yet to meet anyone…unless we already have…no, seriously.

A Buried Past

Carroll-Nellenback et al. consider a “temporal horizon” – a point in history beyond which Earth would no longer retain evidence of previous colonization. Let’s say, for example, a galactic alien civilization landed on Earth billions of years ago, lived thousands of years, then died off. After all this time, virtually no evidence would remain of their presence. So no “we” haven’t met an alien civilization, but it’s possible Earth itself has.

The simulation shows that, given our location in the Galaxy, there is an 89% likelihood that at least a million years could pass without visits from interstellar ships – potentially enough time to erase signs of previous colonization. The point is that between the Galaxy being completely colonized, or being completely empty, the simulation demonstrates that there can be middle grounds – valid responses to the silence which still leave room for technological extraterrestrial life even without contact.

Globular Life?

While the center of the Galaxy is an ideal future realm for SETI research, there are other regions of the Galaxy which mimic the same favourable conditions as the center – Globular Clusters

Globular clusters (GC) are ancient massive collections of stars orbiting about the center of the Galaxy at distances of tens of thousands of light years. Relics from a period of intense star formation catalyzed by galaxy mergers, there are about 150 known GCs in the Milky Way ranging from 10-13 billion years old.

3D Model of known Globular Clusters and their position relative to the rest of the Milky Way Credit: Galaxy’s 3D

GCs are incredibly dense with stars much closer to each other on average than found in the disk of the Milky Way. When considering interstellar travel or communication, we are typically talking about millennia. However, a civilization within a GC would experience travel time between stars on the order of just a few years with communication times of months or even weeks. Problem is that the densities of GCs may negatively impact planet formation as well as the orbital stability of planets.

R. Di Stefano and A. Ray calculate what they call a “GC habitable zone”. We generally use the term “habitable zone” to describe the distance a planet needs to orbit a star to maintain temperatures for liquid water. Earth resides in the habitable zone of the Sun (good thing for us). Rather than a 2 dimensional radius like the orbit of a planet, a GC habitable zone is a three dimensional shell orbiting around the center of the cluster itself. The inner part of the shell’s thickness begins where the GC density drops to where solar systems can survive the gravitational interference of nearby stars. The gravity of a nearby star might pull apart planetary dust rings disrupting the creation of planets. Another star passing near a system could also eject a planet from its parent star.

The outer edge of the shell’s thickness is defined by where the density becomes so low that the average distance between stars is greater than 10,000 AU (Astronomical Units representing the Earth’s distance from the Sun at about 150,000 KM). 10,000 AU is equal to about 2 light months. After this point, the advantages of being in the cluster – namely the short travel and communication times to neighbouring stars – diminish. The zone encompassed by the shell is what Di Stefano and Ray call the GC “sweet spot” for colonization – star systems that are close together facilitating quick travel/communication but not so close that they tear eachother’s systems apart.

Fraser Cain of Universe joined by exoplanet researcher Dr. Jason Wright from Penn State University. Jason Wright was one of the leads on the Galaxy Colonization Simulation

We want the GC sweet spot to encompass mainly lower mass stars which live the longest. Serendipitously, low mass stars also have the smallest radius solar habitable zones. The closer a planet orbits its parent star the less likely it is of being torn away by another star. GCs also experience a phenomenon called “Mass Segregation” where the most massive stars – and therefore the least favorable to habitability in the cluster – find themselves gravitationaly drawn toward the center. This segregation then naturally sorts the cluster from least to best choice systems from core to periphery.

The results are favorable. In a hypothetical GC approaching 100,000 solar masses, the sweet spot encompasses 40% of G stars (yellow dwarfs like our own Sun) and 15% of K and M stars (orange and red dwarfs) in the cluster. That’s a lot of stars. There is even the possibility that planets which have been ejected from systems could still host a civilization because of the combined ambient energy the planet receives from all the stars in the cluster – especially if the civilization has advanced solar energy capture technology. A free floating world of space aliens.

Just throwing out numbers, Di Stefano and Ray suggest that even if only 10% of GC stars have habitable planets, 1% of those support intelligent life, and 1% of those host a communicating civilization, at least one communicating civilization could exist in every GC in the Milky Way. Similar variables assigned to the Milky Way itself – with far lower stellar density – would result in…one communicating civilization (probably us). Changing the percentages to be slightly less conservative would mean more civilizations could exist in the diffuse disk but would be separated by massive distances upwards of 300 light years.

If you were located in a GC, you may try to communicate with the distant disk of the Milky Way. We, unfortunately, have yet to find any direct evidence that planets even exist in GCs. Our techniques for finding exoplanets are impaired by the distance to and densities of GCs. But that doesn’t rule out the possibility. If a civilization does exist in a GC, with quick access to thousands of stars, Di Stefano and Ray say the civilization would essentially be “immortal.”

Globular Cluster M13 Credit: Howard Trottier, SFU Trottier Observatory

We’ve actually beamed a message to a GC – the beautiful M13 Hercules Globular Cluster. Located in the constellation of Hercules, the cluster is 22,000 light years away, 145 light years in diameter, and is comprised of about 100,000 stars. In 1974, a message was sent to M13 from the Arecibo radio telescope (RIP). The message contained the numbers 1 to 10, chemical compounds of DNA, a graphic figure of a human, a graphic of the solar system, and a graphic of the radio telescope itself. Total broadcast time was 3 minutes. Still has a few thousand years to get there.

Likely the low resolution message won’t be discernible by the time it arrives at M13. But perhaps one day we will make contact with a galaxy-spanning civilization. Or, perhaps WE will become a galaxy-spanning civilization. For that story, I’m eagerly awaiting the upcoming screen adaptation of Asimov’s Foundation series!

The Arecibo Message beamed to the M13 Globular Cluster. Creative Commons

Feature Image: Composite image of the Milky Way’s core created by Hubble, Spitzer, and Chandra telescopes. Credit X-ray: NASA/CXC/UMass/D. Wang et al.; Optical: NASA/ESA/STScI/D.Wang et al.; IR: NASA/JPL-Caltech/SSC/S.Stolovy

More to Explore:

The Dynamics of the Transition from Kardashev Type II to Type III Galaxies Favor Technosignature Searches in the Central Regions of Galaxies – IOPscience (Originating Research Article – Open Access)

The Fermi Paradox and the Aurora Effect: Exo-civilization Settlement, Expansion, and Steady States – IOPscience (Open Access)

The Breakthrough Listen Search For Intelligent Life Near the Galactic Center I – NASA/ADS (harvard.edu) (Open Access)

GLOBULAR CLUSTERS AS CRADLES OF LIFE AND ADVANCED CIVILIZATIONS – IOPscience (Open Access)

Transmission of Information by Extraterrestrial Civilizations. – NASA/ADS (harvard.edu) (Open Access)

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Guest “Math class is hard” by David Middleton

ENERGY & ENVIRONMENT

House Democrats are banding together to send Biden a clear climate signal
Democrats across the ideological spectrum want strong action on climate change as part of every legislative move this year.

BY ANTHONY ADRAGNA

07/01/2021

Nearly 60 percent of the House of Representatives Democrats are calling on President Joe Biden to ensure that massive climate change and other environmental investments are incorporated into final infrastructure legislation this year.

More than 120 members, led by Rep. Mike Levin (D-Calif.) And spanning the ideological spectrum from the Progressive Caucus Chair Rep. Pramila Jayapal (D-Wash.) To the centrist Problem Solvers Caucus co-chair Josh Gottheimer (DN .J.).), Reaffirm their support for measures such as a clean energy standard, significant investments in electric vehicles and ten-year clean energy tax credits as part of the eventual deal. It is a signal that democrats from across the ideological spectrum are calling for strong climate protection measures as part of all legislative measures this year.

[…]

politics

Why are numbers so problematic for journalists?

• “Almost 60 percent …”
• “More than 120 members …”

The number of signatories was 134, including the electronic signatures “/ s /”. It wasn’t too difficult to count the actual number.

The US House of Representatives currently has 220 Democrats and 211 Republicans. 4 places are free.

134 signatories would be 61% of the Democrats in the House of Representatives.

134 signatories would make up 31% of the House of Representatives.

It does not appear that Alexandria Occasional Cortex or any other member of “The Squad” was among the signatories. As idiotic as this letter was, it wasn’t foolish enough for the true demons of the Democrats.

The author of this article received a BA in History from Middlebury College in 2010 … Which explains McKibben-style mathematics, Anthony Adragna and Politico receive a Teen Talk Barbie Award.

Help us Obi Wan Joe Manchin, you are our only hope!

The reconciliation seems to have stalled with both WV senators
Non-partisan framework conditions for the infrastructure cannot rely on fossil fuels, underlines Senator Manchin of West Virginia
Package would help rebuild roads, bridges, water systems; Add broadband
by Matt Harvey MANAGING EDITOR June 24, 2021

WASHINGTON (WV News) – With a bipartisan framework for a comprehensive federal, U.S. infrastructure deal Senator Joe Manchin, DW.Va. – one of the key players in Congress on this matter – gave a strong signal that any effort to introduce antifossil energy teachings would be a poison pill for him.

Some attribute the framework the bipartisan group used to U.S. Senator Shelley Moore Capito, RW.Va., who worked with a Republican senatorial group to try to reach an infrastructure deal with the White House.

Manchin and Capito gave strong indications that the Infrastructure Act must go through the regular Senate format with 60 or more votes, not through reconciliation. It is estimated that there are around 65 senators who would approve the Infrastructure Act, at least for the time being.

[…]

WV news

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