Aftermath of the Permian – Triassic Mass Extinction

A new study of fossil fishes from Middle Triassic sediments on the shores of Lake Lugano provides new insights into the recovery of biodiversity following the great mass extinction event at the Permian-Triassic boundary 240 million years ago.

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The largest episode of mass extinction in the history of the Earth, which led to the demise of about 90% of marine organisms and a majority of terrestrial species, took place between the Late Permian and Early Triassic, around 240 million years ago. How long it took for biological communities to recover from such a catastrophic loss of biodiversity remains the subject of controversial debate among paleontologists.

A new study of fossil fishes from Middle Triassic strata on the shores of Lake Lugano throws new light on the issue. The study, undertaken by researchers led by Dr. Adriana López-Arbarello, who is a member of the GeoBiocenter at Ludwig-Maximilians-Universitaet (LMU) in Munich and the Bavarian State Collection for Paleontology and Geology, suggests that the process of recovery was well underway within a few million years. The authors, including Dr. Heinz Furrer of Zurich University and Dr. Rudolf Stockar of the Museo Cantonale di Storia Naturale in Lugano, who led the excavations at the sites, and Dr. Toni Bürgin of the Naturmuseum St. Gallen report their findings in the journal PeerJ.

The fossil fishes analyzed by López-Arbarello and her colleagues originate from Monte San Giorgio in the canton Ticino in Switzerland, which is one of the most important sources of marine fossils from the Middle Triassic in the world. The Monte San Giorgio rises to an altitude of 1000 m on the promontory that separates the southern arms of Lake Lugano in the Southern Swiss Alps. But in the Middle Triassic, it was part of a shallow basin dotted with islands fringed by lagoons, which were separated by reefs from the open sea. “The particular significance of its fossil fauna lies in the careful stratigraphic work that has accompanied the excavations here.

The positions of each of the fossil finds discovered here have been documented to the centimeter,” says Adriana López-Arbarello. On the basis of detailed anatomical studies of new material and a taxonomic re-evaluation of previously known specimens from the locality, she and her colleagues have identified a new genus of fossil neopterygians, which they name Ticinolepis. The Neopterygii include the teleost fishes, which account for more than half of all extant vertebrate species. However, the new fossil species are assigned to the second major group of neopterygians, the Holostei, of which only a handful of species survives today. The researchers assign two new fossil species to the genus Ticinolepis, namely T. longaeva and T. crassidens, which occur in different sedimentary beds within the so-called Besano Formation on Monte San Giorgio.

The two species coexisted side by side but they occupied distinct ecological niches. T. crassidens fed on mollusks and was equipped with jaws and teeth that could handle their hard calcareous shells. T. longaeva was more of a generalist, and was found in waters in which T. crassidens could not survive. The authors interpret the different distribution patterns as a reflection of changing environmental conditions following the preceding mass extinction event.

The less specialized T. longaeva was able to exploit a broader range of food items, and could thus adapt more flexibly to fluctuating conditions. On the other hand, the dietary differentiation between the two species indicates that a variety of well-established ecosystems was available in the Besano Formation at this time. “This in turn suggests that the marine biota is likely to have recovered from the great mass extinction relatively quickly,” Adriana López-Arbarello concludes.

New Study Proposes Short and Long Process of Extinction

A new study of nearly 22,000 fossils finds that ancient plankton communities began changing in important ways as much as 400,000 years before massive die-offs ensued during the first of Earth’s five great extinctions.

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The research, published July 18 in the Early Edition of the Proceedings of the National Academy of Sciences, focused on large zooplankton called graptolites. It suggests that the effects of environmental degradation can be subtle until they reach a tipping point, at which dramatic declines in population begins.

“In looking at these organisms, what we saw was a disruption of community structures – the way in which the plankton were organized in the water column. Communities came to be less complex and dominated by fewer species well before the massive extinction itself,” says co-author H. David Sheets, PhD, professor of physics at Canisius College and associate research professor in the Evolution, Ecology and Behavior graduate program at the University at Buffalo.

This turmoil, occurring in a time of ancient climate change, could hold lessons for the modern world, says co-author Charles E. Mitchell, PhD, professor of geology in the University at Buffalo College of Arts and Sciences.

The shifts took place at the end of the Ordovician Period some 450 million years ago as the planet transitioned from a warm era into a cooler one, leading eventually to glaciation and lower sea levels.

“Our research suggests that ecosystems often respond in stepwise and mostly predictable ways to changes in the physical environment – until they can’t. Then we see much larger, more abrupt, and ecologically disruptive changes,” Mitchell says. “The nature of such tipping point effects are hard to foresee and, at least in this case, they led to large and permanent changes in the composition of the oceans’ living communities.

“I think we need to be quite concerned about where our current ocean communities may be headed or we may find ourselves at the tail end of a similar event – a sixth mass extinction, living in a very different world than we would like.” The study was a partnership between Canisius, UB, St. Francis Xavier University, Dalhousie University and The Czech Academy of Sciences.

A long slide toward oblivion

In considering mass extinction, there is perhaps the temptation to think of such events as rapid and sudden: At one moment in history, various species are present, and the next they are not.

This might be the conclusion you’d draw if you examined only whether different species of graptolites were present in the fossil record in the years immediately preceding and following the Ordovician extinction.

“If you just looked at whether they were present – if they were there or not – they were there right up to the brink of the extinction,” Sheets says. “But in reality, these communities had begun declining quite a while before species started going extinct.”

The research teased out these details by using 21,946 fossil specimens from areas of Nevada in the U.S. and the Yukon in Canada that were once ancient sea beds to paint a picture of graptolite evolution.

The analysis found that as ocean circulation patterns began to shift hundreds of thousands of years before the Ordovician extinction, graptolite communities that previously included a rich array of both shallow- and deep-sea species began to lose their diversity and complexity.

Deep-water graptolites became progressively rarer in comparison to their shallow-water counterparts, which came to dominate the ocean.

“There was less variety of organisms, and the rare organisms got rarer,” Sheets says. “In the aftermath of a forest fire in the modern world, you might find that there are fewer organisms left – that the ecosystem just doesn’t have the same structure and richness as before. That’s the same pattern we see here.”

The dwindling deep-sea graptolites were species that specialized in obtaining nutrients from low-oxygen zones of the ocean. A decrease in the availability of such habitats may have sparked the creatures’ decline, Sheets and Mitchell say.

“Temperature changes drive deep ocean circulations, and we think the deep-water graptolites lost their habitats as the climate changed,” Sheets says. “As the nature of the oceans shifted, their way of life went away.”

Alien Solar System Boasts Tightly Spaced Planets, Unusual Orbits

Tightly spaced planets inside an alien solar system known as Kepler-80 boast a rare orbital configuration.

The study was led by Mariah MacDonald as an undergraduate with Darin Ragozzine, an assistant professor of physics and space sciences, both at Florida Institute of Technology.

The unusual planetary array highlighted in the study deepens the ongoing examination of similar systems known as STIPs – Systems with Tightly-spaced Inner Planets – and contributes to the understanding of how Earth formed.

Located about 1,100 light years away, Kepler-80, named for the NASA telescope that discovered it, features five small planets orbiting in extreme proximity to their star. MacDonald and Ragozzine determined the nature of the exoplanetary system through measurements taken with the telescope.

As early as 2012, Kepler scientists found that all five planets orbit in an area about 150 times smaller than the Earth’s orbit around the Sun, with “years” of about one, three, four, seven and nine days. The planets’ close proximity to each other and their star allowed the Kepler Space Telescope to detect tiny variations (about 0.001 percent) in the length of their “years” due to their mutual gravitational interactions.

Analysis by MacDonald and her collaborators revealed that the outer four planets had masses about four- to six-times that of Earth, though they shared Earth’s rocky composition. All four planets have masses similar to one another, though the two outermost planets are almost twice as big. This was attributed to a very puffy hydrogen/helium atmosphere.

These properties are not uncommon for exoplanets, but having precise compositional estimates for multiple planets in the same planetary system is rare.
Another rare attribute of the Kepler-80 system is that its planets have “synchronized” orbits. “The outer four planets return to almost exactly the same configuration every 27 days,” said Ragozzine. This effect is known as a “resonance” and helps the system remain gravitationally stable.

The study also explained the origin of the synchronized orbits in general – and possibly the tightly-spaced configuration. In a process called migration, the orbits of these planets shrank over time while they were forming. Simulations clearly showed that this migration effect caused the planets to lock into synchronized orbits just like those seen with Kepler-80.

Kepler has discovered hundreds of other STIPs, which consist of three to seven relatively small and closely packed planets that complete orbits in 1 to 100 days. This new form of planetary system, quite different from our own solar system, is changing the way scientists think about how planets form, including the Earth. With all the knowledge gained by the analysis of Kepler-80, this system is granting important insight into how STIPs formed.

First Atmospheric Study Of Earth-Sized Exoplanets Reveals Rocky Worlds

On May 2, scientists from MIT, the University of Liège, and elsewhere announced they had discovered a planetary system, a mere 40 light years from Earth, that hosts three potentially habitable, Earth-sized worlds. Judging from the size and temperature of the planets, the researchers determined that regions of each planet may be suitable for life.

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Now, in a paper published today in Nature, that same group reports that the two innermost planets in the system are primarily rocky, unlike gas giants such as Jupiter. The findings further strengthen the case that these planets may indeed be habitable. The researchers also determined that the atmospheres of both planets are likely not large and diffuse, like that of the Jupiter, but instead compact, similar to the atmospheres of Earth, Venus, and Mars.

The scientists, led by first author Julien de Wit, a postdoc in MIT’s Department of Earth, Atmospheric and Planetary Sciences, came to their conclusion after making a preliminary screening of the planets’ atmospheres, just days after announcing the discovery of the planetary system.

On May 4, the team commandeered NASA’s Hubble Space Telescope and pointed it at the system’s star, TRAPPIST-1, to catch a rare event: a double transit, the moment when two planets almost simultaneously pass in front of their star. The researchers realized the planets would transit just two weeks before the event, thanks to refined estimates of the planets’ orbital configuration, made by NASA’s Spitzer Space Telescope, which had already started to observe the TRAPPIST-1 system.

“We thought, maybe we could see if people at Hubble would give us time to do this observation, so we wrote the proposal in less than 24 hours, sent it out, and it was reviewed immediately,” de Wit recalls. “Now for the first time we have spectroscopic observations of a double transit, which allows us to get insight on the atmosphere of both planets at the same time.”

Using Hubble, the team recorded a combined transmission spectrum of TRAPPIST-1b and c, meaning that as first one planet then the other crossed in front of the star, they were able to measure the changes in wavelength as the amount of starlight dipped with each transit.

“The data turned out to be pristine, absolutely perfect, and the observations were the best that we could have expected,” de Wit says. “The force was certainly with us.”

A rocky sign

The dips in starlight were observed over a narrow range of wavelengths that turned out not to vary much over that range. If the dips had varied significantly, de Wit says, such a signal would have demonstrated the planets have light, large, and puffy atmospheres, similar to that of the gas giant Jupiter.

But that’s not the case. Instead, the data suggest that both transiting planets have more compact atmospheres, similar to those of rocky planets such as Earth, Venus, and Mars.

“Now we can say that these planets are rocky. Now the question is, what kind of atmosphere do they have?” de Wit says. “The plausible scenarios include something like Venus, where the atmosphere is dominated by carbon dioxide, or an Earth-like atmosphere with heavy clouds, or even something like Mars with a depleted atmosphere. The next step is to try to disentangle all these possible scenarios that exist for these terrestrial planets.”

More eyes on the sky

The scientists are now working to establish more telescopes on the ground to probe this planetary system further, as well as to discover other similar systems. The planetary system’s star, TRAPPIST-1, is known as an ultracool dwarf star, a type of star that is typically much cooler than the sun, emitting radiation in the infrared rather than the visible spectrum.

De Wit’s colleagues from the University of Liège came up with the idea to look for planets around such stars, as they are much fainter than typical stars and their starlight would not overpower the signal from planets themselves.

The researchers discovered the TRAPPIST-1 planetary system using TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope), a new kind of ground telescope designed to survey the sky in infrared. TRAPPIST was built as a 60-centimeter prototype to monitor the 70 brightest dwarf stars in the southern sky. Now, the researchers have formed a consortium, called SPECULOOS (Search for habitable Planets Eclipsing ULtra-cOOl Stars), and are building four larger versions of the telescope in Chile, to focus on the brightest ultracool dwarf stars in the skies over the southern hemisphere. The researchers are also trying to raise money to build telescopes in the northern sky.

“Each telescope is about $400,000—about the price of an apartment in Cambridge,” de Wit says.

If the scientists can train more TRAPPIST-like telescopes on the skies, de Wit says, the telescopes may serve as relatively affordable “prescreening tools.” That is, scientists may use them to identify candidate planets that just might be habitable, then follow up with more detailed observations using powerful telescopes such as Hubble and NASA’s James Webb Telescope, which is scheduled to launch in October 2018.

“With more observations using Hubble, and further down the road with James Webb, we can know not only what kind of atmosphere planets like TRAPPIST-1 have, but also what is within these atmospheres,” de Wit says. “And that’s very exciting.”

JUST IN: Antarctic Peninsula Glacier Retreat Caused by Mantle Plumes

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A new study has found for the first time that ocean warming is the primary cause of retreat of glaciers on the western Antarctic Peninsula. The Peninsula is one of the largest current contributors to sea-level rise and this new finding will enable researchers to make better predictions of ice loss from this region.

The research, by scientists at Swansea University and British Antarctic Survey, is published in the journal Science today. The study reports that glaciers flowing to the coast on the western side of the Peninsula show a distinct spatial correlation with ocean temperature patterns. Glaciers in the south are retreating rapidly but those in the north showing little change. Some 90% of the 674 glaciers in this region have retreated since records began in the 1940s.

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Dr Alison Cook, who led the work at Swansea University, says: “Scientists know that ocean warming is affecting large glaciers elsewhere on the continent, but thought that atmospheric temperatures were the primary cause of all glacier changes on the Peninsula. We now know that is not the case.”

“The numerous glaciers on the Antarctic Peninsula give a key insight as to how environmental factors control ice behavior on a wide scale. Almost all glaciers on the western side have fractured ending in the sea. We have been able to monitor changes in their ice fronts using images as far back as the 1940s. Glaciers here are extremely diverse and yet the changes in their frontal positions showed a strong regional pattern.

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“We were keen to understand what was causing the differences, in particular why the glaciers in the north-west showed less retreat than those further South and why there was acceleration in retreat since the 1990s. The ocean temperature records have revealed the crucial link.” It appears to be regional mantle plumes along the continental shelf. The team studied ocean temperature measurements around the Peninsula stretching back several decades, alongside photography and satellite data of the 674 glaciers.

The north-south gradient of increasing glacier retreat was found to show a strong pattern with ocean temperatures, whereby water is cold in the north-west, and becomes progressively warmer at depths below 100m further south. Importantly, the warm water at mid-depths in the southerly region has been warming since as long ago as the 1990s, at the same time as the widespread acceleration in glacier retreat.

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Co-author Professor Mike Meredith at British Antarctic Survey says: “These new findings demonstrate for the first time the ocean plays a major role in controlling the stability of glaciers on the western Antarctic Peninsula.”

“Where mid-depth waters from the deep ocean intrude onto the continental shelf and spread towards the coast, they bring heat from the plumes that cause the glaciers to break up and melt. These waters have become warmer and moved to shallower depths in recent decades, causing glacier retreat to accelerate.”

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Co-author Professor Tavi Murray, who leads the Glaciology Research Group at Swansea University, says: “The glaciers on the Antarctic Peninsula are changing rapidly – almost all of the Peninsula’s glaciers have retreated since the 1940s. We have known the region is a climate warming hotspot for a while, but we could not explain what was causing the pattern of glacier change.”

“This new study shows that a warmer ocean is the key to understanding the behavior of glaciers on the Antarctic Peninsula. Currently the Peninsula makes one of the largest contributions to sea-level rise, which means understanding this link will improve predictions of sea-level rise.”

 

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BREAKING NEWS: New Study Shakes Up Science Community Over Historic Cosmic Ray Blast

This news release goes to the heart of my research. It is as if the astrophysics science community comes clean, having hinted of the seriousness charged particles can do to our solar system and of course Earth. What I have been writing about over the last five years regarding possible scenarios based on factual historic data, pertaining to galactic cosmic rays, setting aside the short-term consequences of the Sun’s 22 year cycle apropos to the expansion and contraction of solar rays such as coronal mass ejections, solar flares, coronal holes and filaments.

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In short, (encourage you to read last 5 or 6 Science of Cycles newsletters) it is galactic cosmic rays which will usher in the upcoming magnetic reversal. It is these smaller, if not smallest charged particles as measured using a electromagnetic spectrometer which cause the most harmful effects to Earth’s core and humans.

I am placing original excerpts below so you can read the words used as to their emphasis in realizing events such as supernovae’s from our galaxy Milky Way, or perhaps even greater distances from neighboring galaxies or celestial orbs can have a profound effect to our solar system and planet.

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Research recently published provided empirical evidence of two prehistoric supernovae exploding about 300 light years from Earth. Now, a follow-up investigation based on computer modeling shows those supernovae likely propagated a significant biological shift on our planet to a long-lasting gust of cosmic radiation, which also affected the atmosphere.

“I was surprised to see as much effect as there was,” said Adrian Melott, professor of physics at the University of Kansas, who co-authored the new paper appearing in The Astrophysical Journal Letters, a peer-reviewed express scientific journal that allows astrophysicists to rapidly publish short notices of significant original research. “I was expecting there to be very little effect at all,” he said. “The supernovae were pretty far away – more than 300 light years – that’s really not very close.”

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According to Melott, “The big thing turns out to be the cosmic rays. The really high-energy ones are pretty rare. The high-energy cosmic rays are the ones that can penetrate the atmosphere. They tear up molecules, they can rip electrons off atoms, and that goes on right down to the ground level. Normally that happens only at high altitude.

Melott’s collaborators on the research are Brian Thomas and Emily Engler of Washburn University, Michael Kachelrieß of the Institutt for fysikk in Norway, Andrew Overholt of MidAmerica Nazarene University and Dimitry Semikoz of the Observatoire de Paris and Moscow Engineering Physics Institute.

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The boosted exposure to cosmic rays from supernovae could have had “substantial effects on the terrestrial atmosphere and fauna.” Fauna pretty much means ‘all living things’. For instance, the research suggested the supernovae might have caused a 20-fold increase in irradiation by muons at ground level on Earth.

“A muon is a cousin of the electron, a couple of hundred times heavier than the electron – they penetrate hundreds of meters of rock,” Melott said. “Normally there are lots of them hitting us on the ground. They mostly just go through us, but because of their large numbers contribute about 1/6 of our normal radiation dose. So if there were 20 times as many, you’re in the ballpark of tripling the radiation dose.”

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Melott said the uptick in radiation from muons would have been high enough to boost the mutation rate and frequency of cancer, but not enormously. Still, if you increased the mutation rate you might speed up evolution.

Indeed, a minor mass extinction around 2.59 million years ago may be connected in part to boosted cosmic rays that could have helped to cool Earth’s climate. The new research results show that the cosmic rays ionize the Earth’s atmosphere in the troposphere – the lowest level of the atmosphere – to a level eight times higher than normal. This would have caused an increase in cloud-to-ground lightning.

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Cosmic rays are inescapable throughout the universe. They can rip right through our atmosphere, damaging DNA and possibly causing cancer and memory loss over the long-term.

“There was climate change around this time,” Melott said. Africa dried out, and a lot of the forest turned into savannah. Around this time and afterwards, we started having glaciations – ice ages – over and over again, and it’s not clear why that started to happen. It’s controversial, but maybe cosmic rays had something to do with it.

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Breaking News: Is Earth’s Atmosphere Leaking?

A new study was released over the weekend stating Earth’s atmosphere is leaking. It is presented as if this is a new phenomena just learned and the researchers delivery paints a picture of scientists running around frantically as if they are huddled together thinking to themselves “oh shiet, we must plug the hole….”

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Here’s the fact: the Earth’s atmosphere has always been “leaking” – sometimes more than others. Once again, it truly is the Science of Cycles that wins the day. The question really at hand here is; what is the cause of these cyclical expansion and contraction periods? For those of you who have been following my work already know the answer. But of course there are always new people discovering ScienceOfCycles.com so I must present where my research leads us. Now I am very happy to say, it is not just my research but several other recently published papers from Universities and governmental agencies have also discovered this new awareness of cycles that extend to our galaxy Milky Way and beyond.

Our home Earth, protects us from most seriously dangerous radiation and electrical surges. It does so by creating a magnetic field which is produced through the geodynamic process of convection in the outer cores liquid iron producing currents.

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What we are witnessing today, is Earth’s natural ability to maintain its ambient rotation and orbital balance. Currently, the Earth’s magnetic field is weakening, which therefore allows a greater amount of charged particles and plasma to enter our atmosphere. As a result, Earth’s core begins to overheat. As a way to expend this overheating, Earth produces more mantle plumes which works their way up through the upper mantle, advances into the asthenoshpere, extends through the lithosphere, and breaks through the crust. This process markedly resembles that of humans  when become overheated ‘sweat’ through their pores cooling the body.

The opposite occurs when the Earth’s core becomes slightly too cool, then mantle plumes dissipate, oceans and atmosphere begin to cool and temperatures may fluctuate and lower…then the cycle starts all over again. The time period between these warming and cooling trends do in fact vary, however, they do maintain short-term, moderate, and long-term cycles. This could be 11 year, 100 year, 1000 year and etc.

I have no illusion of my work being recognized by the major world space agencies, I do not have the pedigree nor do I have some form of contractual agreement with them. However, I have been able to maintain my connection with some of the brightest scientists who do in fact work for said agencies and Universities. Some might call me a colleague, others I surely call my mentors. There will be a time in the not to distant future when you will see my 2012 Equation being announced to the public. But it will not be my name attached to this new discovery. I can assure you it will be one from our government space agency, or Europe or Netherlands. All of which is truly fine with me. And if it’s one with whom I have been working with, I will clap the loudest.

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Before I go on, I hope you will see this new release ties in with the last five or so released scientific papers. From my point of view they all point to the same direction. (see 2012 Equation)

(NASA) Earth’s atmosphere is leaking. Every day, around 90 tons of material escapes from our planet’s upper atmosphere and streams out into space. Although missions such as ESA’s Cluster fleet have long been investigating this leakage, there are still many open questions. How and why is Earth losing its atmosphere – and how is this relevant in our hunt for lie elsewhere in the Universe?

Given the expanse of our atmosphere, 90 tons per day amounts to a small leak. Earth’s atmosphere weighs in at around five quadrillion (5 × 1015) tons so we are in no danger of running out any time soon.

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We have been exploring Earth’s magnetic environment for years using satellites such as ESA’s Cluster mission, a fleet of four spacecraft launched in 2000. Cluster has been continuously observing the magnetic interactions between the Sun and Earth for over a decade and half; this longevity, combined with its multi-spacecraft capabilities and unique orbit, have made it a key player in understanding both Earth’s leaking atmosphere and how our planet interacts with the surrounding Solar System.

Earth’s magnetic field is complex; it extends from the interior of our planet out into space, exerting its influence over a region of space dubbed the magnetosphere.

The magnetosphere – and its inner region (the plasmasphere), a doughnut-shaped portion sitting atop our atmosphere, which co-rotates with Earth and extends to an average distance of 12,427 miles (20,000 km) – is flooded with charged particles and ions that are trapped, bouncing back and forth along field lines.

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At its outer sunward edge, the magnetosphere meets the solar wind, a continuous stream of charged particles – mostly protons and electrons – flowing from the Sun. Here, our magnetic field acts like a shield, deflecting and rerouting the incoming wind as a rock would obstruct a stream of water. This analogy can be continued for the side of Earth further from the Sun – particles within the solar wind are sculpted around our planet and slowly come back together, forming an elongated tube (named the magneto-tail), which contains trapped sheets of plasma and interacting field lines.

However, our magnetosphere shield does have its weaknesses; at Earth’s poles the field lines are open, like those of a standard bar magnet (these locations are named the polar cusps). Here, solar wind particles can head inwards towards Earth, filling up the magnetosphere with energetic particles.

Just as particles can head inwards down these open polar lines, particles can also head outwards. Ions from Earth’s upper atmosphere – the ionosphere, which extends to roughly 621 miles (1000 km) above the Earth – also flood out to fill up this region of space. Although missions such as Cluster have discovered much, the processes involved remain unclear.

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“The question of plasma transport and atmospheric loss is relevant for both planets and stars, and is an incredibly fascinating and important topic. Understanding how atmospheric matter escapes is crucial to understanding how life can develop on a planet,” said Arnaud Masson, ESA’s Deputy Project Scientist for the Cluster mission. “The interaction between incoming and outgoing material in Earth’s magnetosphere is a hot topic at the moment; where exactly is this stuff coming from? How did it enter our patch of space?”

Initially, scientists believed Earth’s magnetic environment to be filled purely with particles of solar origin. However, as early as the 1990s it was predicted that Earth’s atmosphere was leaking out into the plasmasphere – something that has since turned out to be true. Given the expanse of our atmosphere, 90 tons per day amounts to a small leak. Earth’s atmosphere weighs in at around five quadrillion (5 × 1015) tons so we are in no danger of running out any time soon.

Observations have shown sporadic, powerful columns of plasma, dubbed plumes, growing within the plasmasphere, travelling outwards to the edge of the magnetosphere and interacting with solar wind plasma entering the magnetosphere.

More recent studies have unambiguously confirmed another source – Earth’s atmosphere is constantly leaking! Alongside the aforementioned plumes, a steady, continuous flow of material (comprising oxygen, hydrogen and helium ions) leaves our planet’s plasmasphere from the polar regions, replenishing the plasma within the magnetosphere. Cluster found proof of this wind, and has quantified its strength for both overall (reported in a paper published in 2013) and for hydrogen ions in particular (reported in 2009).

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Overall, about 2.2 pounds (1 kg) of material is escaping our atmosphere every second, amounting to almost 90 tons per day. Singling out just cold ions (light hydrogen ions, which require less energy to escape and thus possess a lower energy in the magnetosphere), the escape mass totals thousands of tons per year.

Cold ions are important; many satellites – Cluster excluded – cannot detect them due to their low energies, but they form a significant part of the net matter loss from Earth, and may play a key role in shaping our magnetic environment.

Solar storms and periods of heightened solar activity appear to speed up Earth’s atmospheric loss significantly, by more than a factor of three. However, key questions remain: How do ions escape, and where do they originate? What processes are at play, and which is dominant? Where do the ions go? And how?

One of the key escape processes is thought to be centrifugal acceleration, which speeds up ions at Earth’s poles as they cross the shape-shifting magnetic field lines there. These ions are shunted onto different drift trajectories, gain energy and end up heading away from Earth into the magneto-tail, where they interact with plasma and return to Earth at far higher speeds than they departed with – a kind of boomerang effect.

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Such high-energy particles can pose a threat to space-based technology, so understanding them is important. Cluster has explored this process multiple times during the past decade and a half – finding it to affect heavier ions such as oxygen more than lighter ones, and detecting strong, high-speed beams of ions rocketing back to Earth from the magneto-tail nearly 100 times over the course of three years.

More recently, scientists have explored the process of magnetic reconnection, one of the most efficient physical processes by which the solar wind enters Earth’s magnetosphere and accelerates plasma. In this process, plasma interacts and exchanges energy with magnetic field lines; different lines reconfigure themselves, breaking, shifting around and forging new connections by merging with other lines, releasing huge amounts of energy in the process.

Here, the cold ions are thought to be important. We know that cold ions affect the magnetic reconnection process, for example slowing down the reconnection rate at the boundary where the solar wind meets the magnetosphere (the magnetopause), but we are still unsure of the mechanisms at play.

“In essence, we need to figure out how cold plasma ends up at the magnetopause,” said Philippe Escoubet, ESA’s Project Scientist for the Cluster mission. “There are a few different aspects to this; we need to know the processes involved in transporting it there, how these processes depend on the dynamic solar wind and the conditions of the magnetosphere, and where plasma is coming from in the first place – does it originate in the ionosphere, the plasmasphere, or somewhere else?”

Recently, scientists modeled and simulated Earth’s magnetic environment with a focus on structures known as plasmoids and flux ropes – cylinders, tubes, and loops of plasma that become tangled up with magnetic field lines. These arise when the magnetic reconnection process occurs in the magnetotail and ejects plasmoids both towards the outer tail and towards Earth.

Cold ions may play a significant role in deciding the direction of the ejected plasmoid. These recent simulations showed a link between plasmoids heading towards Earth and heavy oxygen ions leaking out from the ionosphere – in other words, oxygen ions may reduce and quench the reconnection rates at certain points within the magneto-tail that produce tail-ward trajectories, thus making it more favorable at other sites that instead send them Earthwards. These results agree with existing Cluster observations.

Another recent Cluster study compared the two main atmospheric escape mechanisms Earth experiences – sporadic plumes emanating through the plasmasphere, and the steady leakage of Earth’s atmosphere from the ionosphere – to see how they might contribute to the population of cold ions residing at the dayside magnetopause (the magnetosphere-solar wind boundary nearest the Sun).

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Both escape processes appear to depend in different ways on the Interplanetary Magnetic Field (IMF), the solar magnetic field that is carried out into the Solar System by the solar wind. This field moves through space in a spiraling pattern due to the rotation of the Sun, like water released from a lawn sprinkler. Depending on how the IMF is aligned, it can effectively cancel out part of Earth’s magnetic field at the magnetopause, linking up and merging with our field and allowing the solar wind to stream in.

Plumes seem to occur when the IMF is oriented southward (anti-parallel to Earth’s magnetic field, thus acting as mentioned above). Conversely, leaking outflows from the ionosphere occur during northward-oriented IMF. Both processes occur more strongly when the solar wind is either denser or travelling faster (thus exerting a higher dynamic pressure).

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“While there is still much to learn, we’ve been able to make great progress here,” said Masson. “These recent studies have managed to successfully link together multiple phenomena – namely the ionospheric leak, plumes from the plasmasphere, and magnetic reconnection – to paint a better picture of Earth’s magnetic environment. This research required several years of ongoing observation, something we could only get with Cluster.”