NASA’s MMS Finds First Interplanetary Shock

The Magnetospheric Multiscale mission—MMS—has spent the past four years using high-resolution instruments to see what no other spacecraft can. Recently, MMS made the first high-resolution measurements of an interplanetary shock.

These shocks, made of particles and electromagnetic waves, are launched by the Sun. They provide ideal test beds for learning about larger universal phenomena, but measuring interplanetary shocks requires being at the right place at the right time. Here is how the MMS spacecraft were able to do just that.

What’s in a Shock?

Interplanetary shocks are a type of collisionless shock—ones where particles transfer energy through electromagnetic fields instead of directly bouncing into one another. These collisionless shocks are a phenomenon found throughout the universe, including in supernovae, black holes and distant stars. MMS studies collisionless shocks around Earth to gain a greater understanding of shocks across the universe.

Interplanetary shocks start at the Sun, which continually releases streams of charged particles called the solar wind.

The solar wind typically comes in two types—slow and fast. When a fast stream of solar wind overtakes a slower stream, it creates a shock wave, just like a boat moving through a river creates a wave. The wave then spreads out across the solar system. On Jan. 8, 2018, MMS was in just the right spot to see one interplanetary shock as it rolled by.

Catching the Shock

MMS was able to measure the shock thanks to its unprecedentedly fast and high-resolution instruments. One of the instruments aboard MMS is the Fast Plasma Investigation. This suite of instruments can measure ions and electrons around the spacecraft at up to 6 times per second. Since the speeding shock waves can pass the spacecraft in just half a second, this high-speed sampling is essential to catching the shock.

Looking at the data from Jan. 8, the scientists noticed a clump of ions from the solar wind. Shortly after, they saw a second clump of ions, created by ions already in the area that had bounced off the shock as it passed by. Analyzing this second population, the scientists found evidence to support a theory of energy transfer first posed in the 1980s.

MMS consists of four identical spacecraft, which fly in a tight formation that allows for the 3-D mapping of space. Since the four MMS spacecraft were separated by only 12 miles at the time of the shock (not hundreds of kilometers as previous spacecraft had been), the scientists could also see small-scale irregular patterns in the shock. The event and results were recently published in the Journal of Geophysical Research.

Going Back for More

Due to timing of the orbit and instruments, MMS is only in place to see interplanetary shocks about once a week, but the scientists are confident that they’ll find more. Particularly now, after seeing a strong interplanetary shock, MMS scientists are hoping to be able to spot weaker ones that are much rarer and less well understood. Finding a weaker event could help open up a new regime of shock physics.

Magnetic Plasma Pulses Excited By UK-Size Swirls In The Solar Atmosphere

An international team of scientists led by the University of Sheffield have discovered previously undetected observational evidence of frequent energetic wave pulses the size of the UK, transporting energy from the solar surface to the higher solar atmosphere.

Magnetic plasma waves and pulses have been widely suggested as one of the key mechanisms which could answer the long-standing question of why the temperature of the solar atmosphere rises dramatically, from thousands to millions of degrees, as you move away from the solar surface.

There have been many theories put forward, including some developed at the University of Sheffield — for example, heating the plasma by magnetic waves or magnetic plasma — but observational validation of the ubiquity of a suitable energy transport mechanism has proved challenging until now.

By developing innovative approaches, applied mathematicians at the Solar Physics and Space Plasma Research Centre (SP2RC) in the School of Mathematics and Statistics at the University of Sheffield, and the University of Science and Technology of China, have discovered unique observational evidence of plentiful energetic wave pulses, named after the Nobel laureate Hannes Alfvén, in the solar atmosphere.

These short-lived Alfvén pulses have been found to be generated by prevalent photospheric plasma swirls about the size of the British Isles, which are suggested to have a population of at least 150,000 in the solar photosphere at any moment of time.

Professor Robertus Erdélyi (a.k.a. von Fáy-Siebenbürgen), Head of SP2RC, said: “Swirling motions are everywhere in the universe, from sinking water in domestic taps with a size of centimeters, to tornadoes on Earth and on the Sun, solar jets and spiral galaxies with a size of up to 520,000 light years. This work has shown, for the first time, the observational evidence that ubiquitous swirls in the solar atmosphere could generate short-lived Alfvén pulses.

“The generated Alfvén pulses easily penetrate the solar atmosphere along cylinder-like magnetic flux tubes, a form of magnetism a bit like trees in a forest. The pulses could travel all the way upward and reach the top of the solar chromospheric layers, or, even beyond.”

Alfvén modes are currently very hard to observe directly, because they do not cause any local intensity concentrations or rarefactions as they make their journey through a magnetised plasma. They are hard to be observationally distinguished from some other types of magnetic plasma modes, like the well-known transversal magnetic plasma waves, often called kink modes.

“The energy flux carried by the Alfvén pulses we detected now are estimated to be more than 10 times higher than that needed for heating the local upper solar chromosphere,” said Dr Jiajia Liu, postdoctoral research associate.

“The chromosphere is a relatively thin layer between the solar surface and the extremely hot corona. The solar chromosphere appears as a red ring around the Sun during total solar eclipses.”

Professor Erdélyi added: “It has been a fascinating question for the scientific community for a long while — how the Sun and many other stars supply energy and mass to their upper atmospheres. Our results, as part of an exciting UK-China collaboration, involving our very best early-career scientists like Drs Jiajia Liu, Chris Nelson and Ben Snow, are an important step forward in addressing the supply of the needed non-thermal energy for solar and astrophysical plasma heating.

“We believe, these UK-sized photospheric magnetic plasma swirls are also very promising candidates not just for energy but also for mass transportation between the lower and upper layers of the solar atmosphere. Our future research with my colleagues at SP2RC will now focus on this new puzzle. “

FOLLOW UP: Probability of Earth Changing Events Within 14 Day

Historical evidence indicates large significant Earth changing events related to a Full Solar Eclipse. A pattern of events falls within a 28 day ‘window’ – as in window of opportunity. My research exhibits a cluster of natural phenomena had historically occurred 14 days prior to an eclipse – or within 14 days after.

The reason for large events to occur prior to a solar eclipse is not yet fully known. I speculate it is related to celestial alignments whereas charged particles and electromagnetic plasma interacts with our Sun and planetary orbs, one of which is Earth.

Close to and during a full solar eclipse, it is the sudden temperature fluctuation which can cause a chain reaction. Producing a sudden and rapid shift in both the jet stream and ocean currents, can cause the destabilization of set seasonal patterns. Additionally, what is often referred to as Extreme Weather involving tornadoes, hurricanes, straight line winds, and wind shears is almost always related to shifting ocean and jet stream

Although temperature flux may be subtle, if tectonics are at their tipping point, it would not take much to set them off. Additionally, the rapid yet subtle temperature change can cause the expansion and contraction of Earth’s lithosphere, which could set off a chain reaction of tectonic slippage resulting in significant earthquakes and volcanic eruptions.

Remember, the majority of volcanoes are submarine (ocean bottom); hence the rapid shift in ocean temperatures is also prone to set off a rippling effect which is often unpredictable due to the spider webbing tentacles which connect a system of mantle plumes and volcanoes.

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Science Of Cycles keeps you tuned-in and knowledgeable of what we are discovering, and how some of these changes will affect our communities and ways of living.

 

Sun’s History Found Buried In Moon’s Crust

When the Sun was just a baby four billion years ago, it went through violent outbursts of intense radiation, spewing scorching, high-energy clouds and particles across the solar system. These growing pains helped seed life on early Earth by igniting chemical reactions that kept Earth warm and wet. Yet, these solar tantrums also may have prevented life from emerging on other worlds by stripping them of atmospheres and zapping nourishing chemicals.

Just how destructive these primordial outbursts were to other worlds would have depended on how quickly the baby Sun rotated on its axis. The faster the Sun turned, the quicker it would have destroyed conditions for habitability.

This critical piece of the Sun’s history, though, has bedeviled scientists, said Prabal Saxena, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Saxena studies how space weather, the variations in solar activity and other radiation conditions in space, interacts with the surfaces of planets and moons.

Now, he and other scientists are realizing that the Moon, where NASA will be sending astronauts by 2024, contains clues to the ancient mysteries of the Sun, which are crucial to understanding the development of life.

“We didn’t know what the Sun looked like in its first billion years, and it’s super important because it likely changed how Venus’ atmosphere evolved and how quickly it lost water. It also probably changed how quickly Mars lost its atmosphere, and it changed the atmospheric chemistry of Earth,” Saxena said.

The Sun-Moon Connection

Saxena stumbled into investigating the early Sun’s rotation mystery while contemplating a seemingly unrelated one: Why, when the Moon and Earth are made of largely the same stuff, is there significantly less sodium and potassium in lunar regolith, or Moon soil, than in Earth soil?

This question, too, revealed through analyses of Apollo-era Moon samples and lunar meteorites found on Earth, has puzzled scientists for decades — and it has challenged the leading theory of how the Moon formed.

Our natural satellite took shape, the theory goes, when a Mars-sized object smashed into Earth about 4.5 billion years ago. The force of this crash sent materials spewing into orbit, where they coalesced into the Moon.

“The Earth and Moon would have formed with similar materials, so the question is, why was the Moon depleted in these elements?” said Rosemary Killen, an planetary scientist at NASA Goddard who researches the effect of space weather on planetary atmospheres and exospheres.

The two scientists suspected that one big question informed the other — that the history of the Sun is buried in the Moon’s crust.

Killen’s earlier work laid the foundation for the team’s investigation. In 2012, she helped simulate the effect solar activity has on the amount of sodium and potassium that is either delivered to the Moon’s surface or knocked off by a stream of charged particles from the Sun, known as the solar wind, or by powerful eruptions known as coronal mass ejections.

Saxena incorporated the mathematical relationship between a star’s rotation rate and its flare activity. This insight was derived by scientists who studied the activity of thousands of stars discovered by NASA’s Kepler space telescope: The faster a star spins, they found, the more violent its ejections. “As you learn about other stars and planets, especially stars like our Sun, you start to get a bigger picture of how the Sun evolved over time,” Saxena said.

Using sophisticated computer models, Saxena, Killen and colleagues think they may have finally solved both mysteries. Their computer simulations, which they described on May 3 in the The Astrophysical Journal Letters, show that the early Sun rotated slower than 50% of baby stars. According to their estimates, within its first billion years, the Sun took at least 9 to 10 days to complete one rotation.

They determined this by simulating the evolution of our solar system under a slow, medium, and then a fast-rotating star. And they found that just one version — the slow-rotating star — was able to blast the right amount of charged particles into the Moon’s surface to knock enough sodium and potassium into space over time to leave the amounts we see in Moon rocks today.

“Space weather was probably one of the major influences for how all the planets of the solar system evolved,” Saxena said, “so any study of habitability of planets needs to consider it.”

Life Under the Early Sun

The rotation rate of the early Sun is partly responsible for life on Earth. But for Venus and Mars — both rocky planets similar to Earth — it may have precluded it. (Mercury, the closest rocky planet to the Sun, never had a chance.)

Earth’s atmosphere was once very different from the oxygen-dominated one we find today. When Earth formed 4.6 billion years ago, a thin envelope of hydrogen and helium clung to our molten planet. But outbursts from the young Sun stripped away that primordial haze within 200 million years.

As Earth’s crust solidified, volcanoes gradually coughed up a new atmosphere, filling the air with carbon dioxide, water, and nitrogen. Over the next billion years, the earliest bacterial life consumed that carbon dioxide and, in exchange, released methane and oxygen into the atmosphere. Earth also developed a magnetic field, which helped protect it from the Sun, allowing our atmosphere to transform into the oxygen- and nitrogen-rich air we breathe today.

“We were lucky that Earth’s atmosphere survived the terrible times,” said Vladimir Airapetian, a senior Goddard heliophysicist and astrobiologist who studies how space weather affects the habitability of terrestrial planets. Airapetian worked with Saxena and Killen on the early Sun study.

Had our Sun been a fast rotator, it would have erupted with super flares 10 times stronger than any in recorded history, at least 10 times a day. Even Earth’s magnetic field wouldn’t have been enough to protect it. The Sun’s blasts would have decimated the atmosphere, reducing air pressure so much that Earth wouldn’t retain liquid water. “It could have been a much harsher environment,” Saxena noted.

But the Sun rotated at an ideal pace for Earth, which thrived under the early star. Venus and Mars weren’t so lucky. Venus was once covered in water oceans and may have been habitable. But due to many factors, including solar activity and the lack of an internally generated magnetic field, Venus lost its hydrogen — a critical component of water. As a result, its oceans evaporated within its first 600 million years, according to estimates. The planet’s atmosphere became thick with carbon dioxide, a heavy molecule that’s harder to blow away. These forces led to a runaway greenhouse effect that keeps Venus a sizzling 864 degrees Fahrenheit (462 degrees Celsius), far too hot for life.

Mars, farther from the Sun than Earth is, would seem to be safer from stellar outbursts. Yet, it had less protection than did Earth. Due partly to the Red Planet’s weak magnetic field and low gravity, the early Sun gradually was able to blow away its air and water. By about 3.7 billion years ago, the Martian atmosphere had become so thin that liquid water immediately evaporated into space. (Water still exists on the planet, frozen in the polar caps and in the soil.)

After influencing the course for life (or lack thereof) on the inner planets, the aging Sun gradually slowed its pace and continues to do so. Today, it revolves once every 27 days, three times slower than it did in its infancy. The slower spin renders it much less active, though the Sun still has violent outbursts occasionally.

Exploring the Moon, Witness of Solar System Evolution

To learn about the early Sun, Saxena said, you need to look no further than the Moon, one of the most well-preserved artifacts from the young solar system.

“The reason the Moon ends up being a really useful calibrator and window into the past is that it has no annoying atmosphere and no plate tectonics resurfacing the crust,” he said. “So as a result, you can say, ‘Hey, if solar particles or anything else hit it, the Moon’s soil should show evidence of that.'”

Apollo samples and lunar meteorites are a great starting point for probing the early solar system, but they are only small pieces in a large and mysterious puzzle. The samples are from a small region near the lunar equator, and scientists can’t tell with complete certainty where on the Moon the meteorites came from, which makes it hard to place them into geological context.

Since the South Pole is home to the permanently shadowed craters where we expect to find the best-preserved material on the Moon, including frozen water, NASA is aiming to send a human expedition to the region by 2024.

If astronauts can get samples of lunar soil from the Moon’s southernmost region, it could offer more physical evidence of the baby Sun’s rotation rate, said Airapetian, who suspects that solar particles would have been deflected by the Moon’s erstwhile magnetic field 4 billion years ago and deposited at the poles: “So you would expect — though we’ve never looked at it — that the chemistry of that part of the Moon, the one exposed to the young Sun, would be much more altered than the equatorial regions. So there’s a lot of science to be done there.”

BREAKING NEWS: NASA Predicts Solar Cycle 25 Weakest in Last 200 Years

The forecast for the next solar cycle says it will be the weakest of the last 200 years. Research now underway has found a more reliable new method to predict this space weather. The maximum of this next cycle – measured in terms of sunspot numbers, could be 30 to 50% lower than the most recent one – Cycle 24. The results show the next cycle will start in 2020 and reach its maximum in 2025.

The new research was led by Irina Kitiashvili, a researcher with the Bay Area Environmental Research Institute at NASA’s Ames Research Center, in California’s Silicon Valley. It combined observations from two NASA space missions; Solar and Heliospheric Observatory and the Solar Dynamics Observatory with data collected since 1976 from the ground-based National Solar Observatory.

One challenge for researchers working to predict the Sun’s activities is that scientists do not yet completely understand the inner workings of our star. Some factors that play out deep inside the Sun cannot be measured directly. They have to be estimated from measurements of related phenomena on the solar surface like sunspots, coronal holes and filaments.

Kitiashvili’s method differs from other prediction tools in terms of the raw material for its forecast. Previously, researchers used the number of sunspots to represent indirectly the activity of the solar magnetic field. The new approach takes advantage of direct observations of magnetic fields emerging on the surface of the Sun.

NASA has been assigned to procure American astronauts to the Moon in the next five years with a landing on the lunar South Pole. With a calm and quiet space weather forecast for the coming decade, it is a great time to explore.

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Science Of Cycles keeps you tuned-in and knowledgeable of what we are discovering, and how some of these changes will affect our communities and ways of living.

 

Solving The Sun’s Super-Heating Mystery With Parker Solar Probe

It’s one of the greatest and longest-running mysteries surrounding, quite literally, our sun — why is its outer atmosphere hotter than its fiery surface?

University of Michigan researchers believe they have the answer, and hope to prove it with help from NASA’s Parker Solar Probe.

In roughly two years, the probe will be the first human-made craft to enter the zone surrounding the sun where heating looks fundamentally different that what has previously been seen in space. This will allow them to test their theory that the heating is due to small magnetic waves traveling back and forth within the zone.

Solving the riddle would allow scientists to better understand and predict solar weather, which can pose serious threats to Earth’s power grid. And step one is determining where the heating of the sun’s outer atmosphere begins and ends — a puzzle with no shortage of theories.

“Whatever the physics is behind this superheating, it’s a puzzle that has been staring us in the eye for 500 years,” said Justin Kasper, a U-M professor of climate and space sciences and a principal investigator for the Parker mission. “In just two more years, Parker Solar Probe will finally reveal the answer.”

The U-M theory, and how the team will use Parker to test it, is laid out in a paper published June 4 in The Astrophysical Journal Letters.

In this “zone of preferential heating” above the sun’s surface, temperatures rise overall. More bizarre still, individual elements are heated to different temperatures, or preferentially. Some heavier ions are superheated until they’re 10 times hotter than the hydrogen that is everywhere in this area — hotter than the core of the sun.

Such high temperatures cause the solar atmosphere to swell to many times the diameter of the sun and they’re the reason we see the extended corona during solar eclipses. In that sense, Kasper says, the coronal heating mystery has been visible to astronomers for more than a half millenium, even if the high temperatures were only appreciated within the last century.

This same zone features hydromagnetic “Alfvén waves” moving back and forth between its outermost edge and the sun’s surface. At the outermost edge, called the Alfvén point, the solar wind moves faster than the Alfvén speed, and the waves can no longer travel back to the sun.

“When you’re below the Alfvén point, you’re in this soup of waves,” Kasper said. “Charged particles are deflected and accelerated by waves coming from all directions.”

In trying to estimate how far from the sun’s surface this preferential heating stops, U-M’s team examined decades of observations of the solar wind by NASA’s Wind spacecraft.

They looked at how much of helium’s increased temperature close to the sun was washed out by collisions between ions in the solar wind as they traveled out to Earth. Watching the helium temperature decay allowed them to measure the distance to the outer edge of the zone.

“We take all of the data and treat it as a stopwatch to figure out how much time had elapsed since the wind was superheated,” Kasper said. “Since I know how fast that wind is moving, I can convert the information to a distance.”

Those calculations put the outer edge of the superheating zone roughly 10 to 50 solar radii from the surface. It was impossible to be more definitive since some values could only be guessed at.

Initially, Kasper didn’t think to compare his estimate of the zone’s location with the Alfvén point, but he wanted to know if there was a physically meaningful location in space that produced the outer boundary.

After reading that the Alfvén point and other surfaces have been observed to expand and contract with solar activity, Kasper and co-author Kristopher Klein, a former U-M postdoc and new faculty at University of Arizona, reworked their analysis looking at year-to-year changes rather than considering the entire Wind Mission.

“To my shock, the outer boundary of the zone of preferential heating and the Alfvén point moved in lockstep in a totally predictable fashion despite being completely independent calculations,” Kasper said. “You overplot them, and they’re doing the exact same thing over time.”

So does the Alfvén point mark the outer edge of the heating zone? And what exactly is changing under the Alfvén point that superheats heavy ions? We should know in the next couple of years. The Parker Solar Probe lifted off in August 2018 and had its first rendezvous with the sun in November 2018 — already getting closer to the sun than any other human-made object.

In the coming years, Parker will get even closer with each pass until the probe falls below the Alfvén point. In their paper, Kasper and Klein predict it should enter the zone of preferential heating in 2021 as the boundary expands with increasing solar activity. Then NASA will have information direct from the source to answer all manner of long-standing questions.

“With Parker Solar Probe we will be able to definitively determine through local measurements what processes lead to the acceleration of the solar wind and the preferential heating of certain elements,” Klein said. “The predictions in this paper suggest that these processes are operating below the Alfvén surface, a region close to the sun that no spacecraft has visited, meaning that these preferential heating processes have never before been directly measured.”

Kasper is the principal investigator of the Solar Wind Electrons Alphas and Protons Investigation on the Parker Solar Probe. SWEAP’s sensors scoop up the solar wind and coronal particles during each encounter to measure velocity, temperature and density, and shed light on the heating mystery.

The research is funded by NASA’s Wind Mission.

Geomagnetic Storm Headed For Earth Could Mean Auroras Will Be Visible Over Parts Of U.S.

A geomagnetic storm warning has been issued following three coronal mass ejections (CME) from a giant sunspot. The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center said that a minor geomagnetic storm watch is in effect for May 15 and May 16.

As a result of the storm, northern parts of the U.S. may be able to see auroras over the next few nights. A forecast map showing where the auroras may be visible can be seen below.

CMEs come from our sun’s outer atmosphere. This is a region that has extremely strong magnetic fields. When these fields close, they can suddenly eject matter in a huge explosion—a CME. This matter—sometimes a billion tons of it—is ejected into space, impacting any object it comes across.

When a CME explodes in the direction of Earth, the solar material interacts with atoms and molecules in our atmosphere. The collisions produce auroras.

The three CMEs responsible for the latest geomagnetic storm came from the sunspot group Region 2741. The series started on May 10 and material from the first two is expected to arrive on May 15. The third will likely reach Earth on May 16.

“The source location for the CMEs has been associated with disappearing solar filaments (DSF) along areas of the magnetic neutral line in the vicinity of the unipolar sunspot group, Region 2741,” an NOAA statement said.

A solar filament is a long line of colder material that hovers above the sun’s corona. NASA notes that these filaments can float along like this for days before they disappear. “Sometimes they also erupt out into space, releasing solar material in a shower that either rains back down or escapes out into space, becoming a moving cloud known as a coronal mass ejection, or CME,” the space agency noted.

Sunspots are temporary regions on the surface of the sun that are darker and colder than the surrounding area—around 4,500 degrees Celsius cooler.

According to SpaceWeather, the sunspot that the latest three CMEs came from appears to be disintegrating and is no longer able to produce huge CMEs that pose a greater risk to Earth. When the sun does produce large explosions, a strong geomagnetic storm has the potential to cause disruption to GPS systems, satellites and power grids.

At the moment, the sun is in a period of quiet known as the solar minimum. The sun’s activity increases and decreases on an 11-year cycle. The solar maximum, when activity peaks, sees an increase in the number of sunspots. The next solar maximum is expected to peak around 2024.