solar wind Archives

September 23, 2016February 22, 2017 by Fraser Cain

How Can We Save The Sun?

Remember the movie Sunshine, where astronomers learn that the Sun is dying? So a plucky team of astronauts take a nuclear bomb to the Sun, and try to jump-start it with a massive explosion. Yeah, there’s so much wrong in that movie that I don’t know where to start. So I just won’t.

Seriously, a nuclear bomb to cure a dying Sun?

Here’s the thing, the Sun is actually dying. It’s just that it’s going to take about another 5 billion years to run of fuel in its core. And when it does, Cillian Murphy won’t be able to restart it with a big nuke.

But the Sun doesn’t have to die so soon. It’s made of the same hydrogen and helium as the much less massive red dwarf stars. And these stars are expected to last for hundreds of billions and even trillions of years.

Is there anything we can do to save the Sun, or jump-start it when it runs out of fuel in the core?

First, let me explain the problem. The Sun is a main sequence star, and it measures 1.4 million kilometers across. Like ogres and onions, the Sun is made of layers.

The interior structure of the Sun. Credit: Wikipedia Commons/kelvinsong

The innermost layer is the core. That’s the region where the temperature and pressure is so great that atoms of hydrogen are mashed together so tightly they can fuse into helium. This fusion reaction is exothermic, which means that it gives off more energy than it consumes.

The excess energy is released as gamma radiation, which then makes its way through the star and out into space. The radiation pushes outward, and counteracts the inward force of gravity pulling it together. This balance creates the Sun we know and love.

Outside the core, temperatures and pressures drop to the point that fusion can no longer happen. This next region is known as the radiative zone. It’s plenty hot, and the photons of gamma radiation generated in the core of the Sun need to bounce randomly from atom to atom, maybe for hundreds of thousands of years to finally escape. But it’s not hot enough for fusion to happen.

Outside the radiative zone is the convective zone. This is where the material in the Sun is finally cool enough that it can move around like a lava lamp. Hot blobs of plasma pick up enormous heat from the radiative zone, float up to the surface of the Sun, release their heat and then sink down again.

The only fuel the Sun can use for fusion is in the core, which accounts for only 0.8% of the Sun’s volume and 34% of its mass. When it uses up that hydrogen in the core, it’ll blow off its outer layers into space and then shrink down into a white dwarf.

The radiative zone acts like a wall, preventing the mixing convective zone from reaching the solar core.

If the Sun was all convective zone, then this wouldn’t be a problem, it would be able to go on mixing its fuel, using up all its hydrogen instead of this smaller fraction. If the Sun was more like a red dwarf, it could last much longer.

GJ1214b, shown in this artist’s view, is a super-Earth orbiting a red dwarf star 40 light-years from Earth. Credit: NASA, ESA, and D. Aguilar (Harvard-Smithsonian Center for Astrophysics) — Red dwarf stars burn for much longer than our Sun. Credit: NASA, ESA, and D. Aguilar (Harvard-Smithsonian Center for Astrophysics)

In order to save the Sun, to help it last longer than the 5 billion years it has remaining, we would need some way to stir up the Sun with a gigantic mixing spoon. To get that unburned hydrogen from the radiative and convective zones down into the core.

One idea is that you could crash another star into the Sun. This would deliver fresh fuel, and mix up the Sun’s hydrogen a bit. But it would be a one time thing. You’d need to deliver a steady stream of stars to keep mixing it up. And after a while you would accumulate enough mass to create a supernova. That would be bad.

But another option would be to strip material off the Sun and create red dwarfs. Stars with less than 35% the mass of the Sun are fully convective. Which means that they don’t have a radiative zone. They fully mix all their hydrogen fuel into the core, and can last much longer.

Imagine a future civilization tearing the Sun into 3 separate stars, each of which could then last for hundreds of billions of years, putting out only 1.5% the energy of the Sun. Huddle up for warmth.

But if you want to take this to the extreme, tear the Sun into 13 separate red dwarf stars with only 7.5% the mass of the Sun. These will only put out .015% the light of the Sun, but they’ll sip away at their hydrogen for more than 10 trillion years.

Stick the Earth in the middle and you'd have some very odd sunsets, not to mention orbital dynamics. Created with Universe Sandbox ² — Stick the Earth in the middle and you’d have some very odd sunrises and sunsets, not to mention orbital dynamics. Created with Universe Sandbox ²

But how can you get that hydrogen off the Sun? Lasers, of course. Using a concept known as stellar lifting, you could direct a powerful solar powered laser at a spot on the Sun’s surface. This would heat up the region, and generate a powerful solar wind. The Sun would be blasting its own material into space. Then you could use magnetic fields or gravity to direct the outflows and collect them into other stars. It boggles our imagination, but it would be a routine task for Type III Civilization engineers on star dismantling duty.

So don’t panic that our Sun only has a few billion years of life left. We’ve got options. Mind bendingly complicated, solar system dismantling options. But still… options.

July 15, 2016September 20, 2016 by Evan Gough

A Dark Region Is Growing Eerily On The Sun’s Surface

NASA's Solar Dynamics Observatory has captured images of a growing dark region on the surface of the Sun. Called a coronal hole, it produces high-speed solar winds that can disrupt satellite communications. Image: Solar Dynamics Observatory / NASA

NASA has spotted an enormous black blotch growing on the surface of the Sun. It looks eerie, but this dark region is nothing to fear, though it does signal potential disruption to satellite communications.

The dark region is called a coronal hole, an area on the surface of the Sun that is cooler and less dense than the surrounding areas. The magnetic fields in these holes are open to space, which allows high density plasma to flow out into space. The lack of plasma in these holes is what makes them appear dark. Coronal holes are the origin of high-speed solar winds, which can cause problems for satellite communications.

The images were captured by the Solar Dynamics Observatory (SDO) on July 11th. Tom Yulsman at Discover’s ImaGeo blog created a gif from several of NASA’s images.

High-speed solar winds are made up of solar particles which are travelling up to three times faster than the solar wind normally does. Though satellites are protected from the solar wind, extremes like this can still cause problems.

Coronal holes may look like a doomsday warning; an enormous black hole on the surface of our otherwise placid looking Sun is strange looking. But these holes are a part of the natural life of the Sun. And anyway, they only appear in extreme ultraviolet and x-ray wavelengths.

The holes tend to appear at the poles, due to the structure of the Sun’s magnetosphere. But when they appear in more equatorial regions of the Sun, they can cause intermittent problems, as the high-speed solar wind they generate is pointed at the Earth as the Sun rotates.

In June 2012, a coronal hole appeared that looked Big Bird from Sesame Street.

The "Big Bird" coronal hole appeared on the Sun in June 2012. It caused a powerful storm that was considered a near miss for Earth. Image: NASA/AIA — The “Big Bird” coronal hole appeared on the Sun in June 2012. It was the precursor to a powerful storm that was considered a near miss for Earth. Image: NASA/AIA

The Big Bird hole was the precursor to an extremely powerful solar storm, the most powerful one in 150 years. Daniel Baker, of the University of Colorado’s Laboratory of Atmospheric and Space Physics, said of that storm, “If it had hit, we would still be picking up the pieces.” We were fortunate that it missed us, as these enormous storms have the potential to damage power grids on the surface of the Earth.

It seems unlikely that any solar wind that reaches Earth as a result of this current coronal hole will cause any disruption to us here on Earth. But it’s not out of the question. In 1989 a solar storm struck Earth and knocked out power in the province of Quebec in Canada.

It may be that the only result of this coronal hole, and any geomagnetic storms it creates, are more vivid auroras.

Those are something everyone can appreciate and marvel at. And you don’t need an x-ray satellite to see them.

July 12, 2016September 20, 2016 by Matt Williams

ESA Discovers Where All The Missing Socks Have Been Going

earth's atmosphere has an ozone hole (not seen here) — Earth’s atmosphere seen from space. The top layer of the stratosphere is the ozone layer, which protects us from harmful solar UV. Scientists are tracking the ozone hole over the Antarctic. Credit: NASA

We here at Earth are fortunate that we have a viable atmosphere, one that is protected by Earth’s magnetosphere. Without this protective envelope, life on the surface would be bombarded by harmful radiation emanating from the Sun. However, Earth’s upper atmosphere is still slowly leaking, with about 90 tonnes of material a day escaping from the upper atmosphere and streaming into space.

And although astronomers have been investigating this leakage for some time, there are still many unanswered questions. For example, how much material is being lost to space, what kinds, and how does this interact with solar wind to influence our magnetic environment? Such has been the purpose of the European Space Agency’s Cluster project, a series of four identical spacecraft that have been measuring Earth’s magnetic environment for the past 15 years.

Understanding our atmosphere’s interaction with solar wind first requires that we understand how Earth’s magnetic field works. For starters, it extends from the interior of our planet (and is believed to be the result of a dynamo effect in the core), and reaches all the way out into space. This region of space, which our magnetic field exerts influence over, is known as the magnetosphere.

The four Cluster spacecraft crossing the northern cusp of Earth's magnetosphere. Credit: ESA/AOES Medialab — *The four Cluster spacecraft crossing the northern cusp of Earth’s magnetosphere. Credit: ESA/AOES Medialab*

The inner portion of this magnetosphere is called the plasmasphere, a donut-shaped region which extends to a distance of about 20,000 km from the Earth and co-rotates with it. The magnetosphere is also flooded with charged particles and ions that get trapped inside, and then are sent bouncing back and forth along the region’s field lines.

At its forward, Sun-facing edge, the magnetosphere meets the solar wind – a stream of charged particles flowing from the Sun into space. The spot where they make contact is known as the “Bow Shock”, which is so-named because its magnetic field lines force solar wind to take on the shape of a bow as they pass over and around us.

As the solar wind passes over Earth’s magnetosphere, it comes together again behind our planet to form a magnetotail – an elongated tube which contains trapped sheets of plasma and interacting field lines. Without this protective envelope, Earth’s atmosphere would have been slowly stripped away billions of years ago, a fate that is now believed to have befallen Mars.

That being said, Earth’s magnetic field is not exactly hermetically sealed. For example, at our planet’s poles, the field lines are open, which allows solar particles to enter and fill our magnetosphere with energetic particles. This process is what is responsible for Aurora Borealis and Aurora Australis (aka. the Northern and Southern Lights).

*An illustration showing the natural barrier Earth gives us against solar radiation. Credit: NASA.*

At the same time, particles from Earth’s upper atmosphere (the ionosphere) can escape the same way, traveling up through the poles and being lost to space. Despite learning much about Earth’s magnetic fields and how plasma is formed through its interaction with various particles, much about the whole process has been unclear until quite recently.

As Arnaud Masson, ESA’s Deputy Project Scientist for the Cluster mission stated in an ESA press release:

“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. 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?“

Given that our atmosphere contains 5 quadrillion tons of matter (that’s 5 x 10¹⁵, or 5,000,000 billion tons), a loss of 90 tons a day doesn’t amount to much. However, this number does not include the mass of “cold ions” that are regularly being added. This term is typically used to described the hydrogen ions that we now know are being lost to the magnetosphere on a regular basis (along with oxygen and helium ions).

Since hydrogen requires less energy to escape our atmosphere, the ions that are created once this hydrogen becomes part of the plasmasphere also have low energy. As a result, they have been very difficult to detect in the past. What’s more, scientists have only known about this flow of oxygen, hydrogen and helium ions – which come from the Earth’s polar regions and replenish plasma in the magnetosphere – for a few decades.

Illustration of ions flowing out from the polar cap towards the magnetotail. Credit: ESA - C. Carreau — *Illustration of ions flowing out from the polar cap towards the magnetotail. Credit: ESA – C. Carreau*

Prior to this, scientists believed that solar particles alone were responsible for plasma in Earth’s magnetosphere. But in more recent years, they have come to understand that two other sources contribute to the plasmasphere. The first are sporadic “plumes” of plasma that grow within the plasmasphere and travel outwards towards the edge of the magnetosphere, where they interact with solar wind plasma coming the other way.

The other source? The aforementioned atmospheric leakage. Whereas this consists of abundant oxygen, helium and hydrogen ions, the cold hydrogen ions appear to play the most important role. Not only do they constitute a significant amount of matter lost to space, and may play a key role in shaping our magnetic environment. What’s more, most of the satellites currently orbiting Earth are unable to detect the cold ions being added to the mix, something which Cluster is able to do.

In 2009 and in 2013, the Cluster probes were able to characterize their strength, as well as that of other sources of plasma being added to the Earth’s magnetosphere. When only the cold ions are considered, the amount of atmosphere being lost o space amounts to several thousand tons per year. In short, its like losing socks. Not a big deal, but you’d like to know where they are going, right?

This has been another area of focus for the Cluster mission, which for the last decade and a half has been attempting to explore how these ions are lost, where they come from, and the like. As Philippe Escoubet, ESA’s Project Scientist for the Cluster mission, put it:

“In essence, we need to figure out how cold plasma ends up at the magnetopause. 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?“

*Color illustration showing the scale of planets in our solar system, focusing on Jupiter and Saturn. Credit: NASA*

The reasons for understanding this are clear. High energy particles, usually in the form of solar flares, can pose a threat to space-based technology. In addition, understanding how our atmosphere interacts with solar wind is also useful when it comes to space exploration in general. Consider our current efforts to locate life beyond our own planet in the Solar System. If there is one thing that decades of missions to nearby planets has taught us, it is that a planet’s atmosphere and magnetic environment are crucial in determining habitability.

Within close proximity to Earth, there are two examples of this: Mars, which has a thin atmosphere and is too cold; and Venus, who’s atmosphere is too dense and far too hot. In the outer Solar System, Saturn’s moon Titan continues to intrigue us, mainly because of the unusual atmosphere. As the only body with a nitrogen-rich atmosphere besides Earth, it is also the only known planet where liquid transfer takes place between the surface and the atmosphere – albeit with petrochemicals instead of water.

Moreover, NASA’s Juno mission will spend the next two years exploring Jupiter’s own magnetic field and atmosphere. This information will tell us much about the Solar System’s largest planet, but it is also hoped to shed some light on the history planetary formation in the Solar System.

In the past fifteen years, Cluster has been able to tell astronomers a great deal about how Earth’s atmosphere interacts with solar wind, and has helped to explore magnetic field phenomena that we have only begun to understand. And while there is much more to be learned, scientists agree that what has been uncovered so far would have been impossible without a mission like Cluster.

Further Reading: ESA

June 21, 2016July 21, 2016 by Evan Gough

Huge Plasma Tsunamis Hitting Earth Explains Third Van Allen Belt

This is an illustration to explain the dynamics of the ultra-relativistic third Van Allen radiation belt. Credit: Andy Kale

The dynamic relationship between Earth and the Sun two sides. The warmth from the Sun makes life on Earth possible, but the rest of the Sun’s intense energy pummels the Earth, and could destroy all life, given the chance. But thanks to our magnetosphere, we are safe.

The magnetosphere is our protective shield. It’s created by the rotation of the molten outer core of the Earth, composed largely of iron and nickel. It absorbs and deflects plasma from the solar wind. The interactions between the magnetosphere and the solar wind are what create the beautiful auroras at Earth’s poles.

Visualization of the solar wind encountering Earth's magnetic "defenses" known as the magnetosphere. Clouds of southward-pointing plasma are able to peel back layers of the Sun-facing bubble and stack them into layers on the planet's nightside (center, right). The layers can be squeezed tightly enough to reconnect and deliver solar electrons (yellow sparkles) directly into the upper atmosphere to create the aurora. Credit: JPL — Visualization of the solar wind encountering Earth’s magnetic “defenses” known as the magnetosphere. Clouds of southward-pointing plasma are able to peel back layers of the Sun-facing bubble and stack them into layers on the planet’s nightside (center, right). The layers can be squeezed tightly enough to reconnect and deliver solar electrons (yellow sparkles) directly into the upper atmosphere to create the aurora. Credit: JPL

In the inner regions of Earth’s magnetosphere are the Van Allen belts, named after their discoverer James Van Allen. They consist of charged particles, mostly from the Sun, and are held in place by the magnetosphere. Usually, there are two such belts.

The Van Allen radiation belts surrounding Earth. Image: NASA

But the output from the Sun is not stable. There are periods of intense energy output from the Sun, and when that happens, a third, transient belt can be created. Up until now, the nature of this third belt has been a puzzle. New research from the University of Alberta has shown how this phenomena can happen.

Researchers have shown how a so-called “space tsunami” can create this third belt. Intense ultra-low frequency plasma waves can transport the outer part of the radiation belt into interplanetary space, and create the third, transient belt.

The lead author for this study is physics professor Ian Mann from the University of Alberta, and former Canada Research Chair in Space Physics. “Remarkably, we observed huge plasma waves,” said Mann. “Rather like a space tsunami, they slosh the radiation belts around and very rapidly wash away the outer part of the belt, explaining the structure of the enigmatic third radiation belt.”

This new research also sheds light on how these “tsunamis” help reduce the threat of radiation to satellites during other space storms. “Space radiation poses a threat to the operation of the satellite infrastructure upon which our twenty-first century technological society relies,” adds Mann. “Understanding how such radiation is energized and lost is one of the biggest challenges for space research.”

It’s not just satellites that are at risk of radiation though. When solar wind is most active, it can create extremely energetic space storms. They in turn create intense radiation in the Van Allen belts, which drive electrical currents that could damage our power grids here on Earth. These types of storms have the potential to cause trillions of dollars worth of damage.

A better understanding of this space radiation, and an ability to forecast it, are turning out to be very important to our satellite operations, and to our exploration of space.

The Van Allen belts were discovered in 1958, and classified into an inner and an outer belt.

The Van Allen Belts around Earth. The inner red belt is mostly protons, and the outer blue belt is mostly electrons. Image Credit: NASA

In 2013, probes reported a third belt which had never before been seen. It lasted a few weeks, then vanished, and its cause was not known. Thanks to Mann and his team, we now know what was behind that third belt.

“We have discovered a very elegant explanation for the dynamics of the third belt,” says Mann. “Our results show a remarkable simplicity in belt response once the dominant processes are accurately specified.”

An understanding of the radiation in and around Earth and the Van Allen belts is of growing importance to us, as we expand our presence in space. Our technological society relies increasingly on satellite communications, and on GPS satellites. Radiation in the form of high-energy electrons can wreak havoc on satellites. In fact, this type of radiation is sometimes referred to as a satellite killer. Satellites require robust design to be protected from them.

Organizations like the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) and the International Living with a Star (ILWS) Program are attempts to address the threat that radiation poses to our system of satellites.

May 11, 2016May 15, 2016 by Matt Williams

Thanks, Comet Pluto. Solar System Nomenclature Needs A Major Rethink

New Horizon's July 2015 flyby of Pluto captured this iconic image of the heart-shaped region called Tombaugh Regio. Credit: NASA/JHUAPL/SwRI.

Pluto can’t seem to catch a break lately. After being reclassified in 2006 by the International Astronomical Union, it seemed that what had been the 9th planet of the Solar System was now relegated to the status of “dwarf planet” with the likes of Ceres, Eris, Haumea, and Makemake. Then came the recent announcements that the title of “Planet 9” may belong to an object ten times the mass of Earth located 700 AU from our Sun.

And now, new research has been produced that indicates that Pluto may need to be reclassified again. Using data provided by the New Horizons mission, researchers have shown that Pluto’s interaction with the Sun’s solar wind is unlike anything observed in the Solar System thus far. As a result, it would seem that the debate over how to classify Pluto, and indeed all astronomical bodies, is not yet over.

Continue reading “Thanks, Comet Pluto. Solar System Nomenclature Needs A Major Rethink”

April 6, 2016April 15, 2016 by Evan Gough

New Horizons Did Amazing Work Before Even Arriving At Pluto

The solar wind data collected by New Horizons will help create more accurate models of the space environment in our Solar System. Image: NASA's Goddard Space Flight Center Scientific Visualization Studio, the Space Weather Research Center (SWRC) and the Community-Coordinated Modeling Center (CCMC), Enlil and Dusan Odstrcil (GMU)

Anybody with an ounce of intellectual curiosity (and an internet connection) has seen the images of Pluto and its system taken by the New Horizons probe. The images and data from New Horizons have opened the door to Pluto’s atmosphere, geology, and composition. But New Horizons wasn’t entirely dormant during its 9 year, billion-plus mile journey to Pluto.

New Horizons returned 3 years worth of data on the solar wind that sweeps through the near-emptiness of space. The solar wind is the stream of particles that is released from the upper atmosphere of the Sun, called the corona. The Sun’s solar wind is what creates space weather in our solar system, and the wind itself varies in temperature, speed, and density.

The solar wind data from New Horizons, which NASA calls an “unprecedented set of observations,” is filling in a gap in our knowledge. Observatories like the Solar Dynamics Observatory (SDO) and the Solar and Heliospheric Observatory (SOHO) are studying the Sun up close, and the Voyager probes have sampled the solar wind near the edge of the heliosphere, where the solar wind meets interstellar space, but New Horizons is giving us our first look at the solar wind in Pluto’s region of space.

This solar wind data should shed some light on a number of things, including the dangerous radiation astronauts face when in space. There is a type of particle with extreme energy levels called anomalous cosmic rays. When travelling close to Earth, these high-velocity rays can be a serious radiation hazard to astronauts.

The data from New Horizons reveals particles that pick up an acceleration boost, which makes them exceed their initial speed. It’s thought that these particles could be the precursors to anomalous cosmic rays. A better understanding of this might lead to a better way to protect astronauts.

These same rays have other effects further out in space. It looks like they are partly responsible for shaping the edge of the heliosphere; the region in space where the solar wind meets the interstellar medium.

New Horizons has also told us something about the structure of the solar wind the further it travels from the Sun. Close to the Sun, phenomena like coronal mass ejections (CMEs) have a clearly discernible structure. And the differences in the solar wind, in terms of velocity, density, and temperature, are also discernible. They’re determined by the region of the Sun they came from. New Horizons found that far out in the solar system, these structures have changed.

“At this distance, the scale size of discernible structures increases, since smaller structures are worn down or merge together,” said Heather Elliott, a space scientist at the Southwest Research Institute in San Antonio, Texas, and the lead author of a paper to be published in the Astrophysical Journal. “It’s hard to predict if the interaction between smaller structures will create a bigger structure, or if they will flatten out completely.”

The Voyager probes measured the solar wind as they travelled through our Solar System into the interstellar medium. They’ve told us a lot about the solar wind in the more distant parts of our system, but their instruments aren’t as sensitive and advanced as New Horizons’. This second data set from New Horizons is helping to fill in the blanks in our knowledge.

November 5, 2015December 23, 2015 by Ken Kremer

NASA’s MAVEN Orbiter Discovers Solar Wind Stripped Away Mars Atmosphere Causing Radical Transformation

Artist’s rendering of a solar storm hitting Mars and stripping ions from the planet's upper atmosphere. Credits: NASA/GSFC

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) orbiter mission has determined that ancient Mars suffered drastic climate change and lost its thick atmosphere and surface bodies of potentially life giving liquid water because it lost tremendous quantities of gas to space via stripping by the solar wind, based on new findings that were announced today, Nov. 5, at a NASA media briefing and in a series of scientific publications.

The process of Mars dramatic transformation from a more Earth-like world to its barren state today started about 4.2 Billion years ago as the shielding effect of the global magnetic field was lost as the planets internal dynamo cooled, Bruce Jakosky, MAVEN principal investigator at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder, told Universe Today.

The radical transformation of ancient Mars from a warm world with significant bodies of standing water that could have supported life, to its current state as a cold, arid and desert-like world that’s rather inhospitable to life was caused by the loss of most the planet’s atmosphere as powerful streams of solar wind particles crashed into it and stripped it away due to the loss of the protective magnetic field as the planets core cooled.

“We think that the early magnetic field that Mars had would have protected the planet from direct impact by the solar wind and would have kept it from stripping gas off,” Jakosky told me.

“So it would have been the turn off of the magnetic field, that would have allowed the turn on of stripping of the atmosphere by the solar wind.”

“The evidence suggests that the magnetic field disappeared about 4.2 Billion years ago.”

The period of abundant surface water actively carving the Martian geology lasted until about 3.7 Billion years ago. The loss of the atmosphere by stripping of the solar wind took place from about 4.2 to 3.7 Billion years ago.

Billions of years ago, Mars was a very different world. Liquid water flowed in long rivers that emptied into lakes and shallow seas. A thick atmosphere blanketed the planet and kept it warm. Credit: NASA

With the release of today’s results, the MAVEN science team has accomplished the primary goal of the mission, which was to determine how and why Mars lost its early, thick atmosphere and water over the past four billion years. The atmosphere is composed mostly of carbon dioxide.

Since water is a prerequisite for life as we know it, determining its fate and longevity on Mars is crucial for determining the habitability of the Red Planet and its potential for supporting martian microbes, past of present if they ever existed.

“The NASA Mars exploration program has been focused on finding water,” said Michael Meyer, lead scientist for the Mars Exploration Program at NASA Headquarters.

“Water is the prime ingredient needed for life. It is a major factor in the climate and for shaping geology. And it is a critical resource for future human exploration.”

NASA’s goal is to send humans on a ‘Journey to Mars’ during the 2030s.

This NASA video shows a visualization of the solar wind striking Mars:

Video caption: Created using data from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission, this visualization shows how the solar wind strips ions from the Mars’ upper atmosphere into space. Credits: NASA-GSFC/CU Boulder LASP/University of Iowa

MAVEN arrived in orbit at Mars just over one year ago on Sept. 21, 2014.

The $671 Million MAVEN spacecraft’s goal is to study Mars tenuous upper atmosphere in detail for the very first time by any spacecraft and to explore the mechanisms of how the planet lost its atmosphere and life giving water over billions of years as well as determine the rate of atmospheric loss.

The new MAVEN data have enabled researchers to measure the rate of Mars atmospheric loss of gas to space via the action of solar wind stripping as well as the erosional effect of solar storms.

Based on measurements from MAVEN’s suite of nine state-of-the-art scientific instruments, the solar wind is stripping away gas at a rate of about 100 grams (equivalent to roughly 1/4 pound) every second today, in the form of carbon dioxide and oxygen, said David Brain, MAVEN co-investigator at LASP.

“Most of the stripping [of the Martian atmosphere] by the solar wind at Mars was thought to have taken place very early in the history of the solar system when the sun was much more active and when the solar wind was more intense. So today the rate of loss at Mars is low,” Jakosky said at the briefing.

“Today’s Mars is a cold dry desert-like environment. The atmosphere is thin and it’s not capable of sustaining liquid water at the surface today, it would freeze or evaporate very quickly. However when we look at ancient Mars we see a different type of surface, one that had valleys that looked like they were carved by water and lakes that were standing for long periods of time. We see an environment that was much more able to support liquid water.”

The MAVEN results were published today in nearly four dozen scientific papers in the Nov. 5 issues of the journals Science and Geophysical Research Letters.

I asked Jakosky; How much gas would have been lost from ancient Mars and what is the rough estimate for the ancient rate of loss to arrive at Mars thin atmosphere today?

“For the amount of gas that we think you would have to have been removed – let me start with the current Mars atmosphere which has a thickness of 6 millibars, that’s just under 1% as thick as the Earth’s atmosphere,” Jakosky replied.

“So we think you would have to remove an amount of gas that is about equivalent to what’s in Earth’s atmosphere today.”

“So the rate would have to have been a factor of about 100 to 1000 times higher, than today’s loss of 100 grams per second in order to have removed the gas early in that time period, which is consistent with what the models have predicted that the loss rate would have been back then in early history.”

NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft celebrated one Earth year in orbit around Mars on Sept. 21, 2015. MAVEN was launched to Mars on Nov. 18, 2013 from Cape Canaveral Air Force Station in Florida and successfully entered Mars’ orbit on Sept. 21, 2014. Credit: NASA

What is the solar wind and how does it strip away the atmosphere?

“The solar wind is a stream of particles, mainly protons and electrons, flowing from the sun’s atmosphere at a speed of about one million miles per hour. The magnetic field carried by the solar wind as it flows past Mars can generate an electric field, much as a turbine on Earth can be used to generate electricity. This electric field accelerates electrically charged gas atoms, called ions, in Mars’ upper atmosphere and shoots them into space,” according to a NASA description.

MAVEN is NASA’s next Mars orbiter and is due to blastoff on Nov. 18 from Cape Canaveral, Florida. It will study the evolution of the Red Planet’s atmosphere and climate. Universe Today visited MAVEN inside the clean room at the Kennedy Space Center. With solar panels unfurled, this is exactly how MAVEN looks when flying through space and circling Mars. Credit: Ken Kremer/kenkremer.com

MAVEN is just now completing its primary mission and starts the extended mission phase on Nov. 16.

The 5,400 pound MAVEN probe carries nine sensors in three instrument suites to study why and exactly when did Mars undergo the radical climatic transformation.

MAVEN’s observations will be tied in with NASA’s ongoing Curiosity and Opportunity surface roving missions as well as MRO and Mars Odyssey to provide the most complete picture of the fourth rock from the sun that humanity has ever had.

MAVEN thundered to space on Nov. 18, 2013 following a flawless blastoff from Cape Canaveral Air Force Station’s Space Launch Complex 41 atop a powerful United Launch Alliance Atlas V rocket.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

September 27, 2015August 22, 2018 by Matt Williams

The Sun

This image from the Solar and Heliospheric Observatory (SOHO) Extreme ultraviolet Imaging Telescope (EIT) image shows large magnetically active regions and a pair of curving erupting prominences on June 28, 2000 during the current solar cycle 23 maximum. Prominences are huge clouds of relatively cool dense plasma suspended in the Sun's hot, thin corona. Magnetically active regions cause the principal total solar irradiance variations during each solar cycle. The hottest areas appear almost white, while the darker red areas indicate cooler temperatures. Credit: NASA & European Space Agency (ESA) — The Sun. Credit: NASA & European Space Agency (ESA)

The Sun is the center of the Solar System and the source of all life and energy here on Earth. It accounts for more than 99.86% of the mass of the Solar System and it’s gravity dominates all the planets and objects that orbit it. Since the beginning of history, human beings have understood the Sun’s importance to our world, it’s seasons, the diurnal cycle, and the life-cycle of plants.

Because of this, the Sun has been at the center of many ancient culture’s mythologies and systems of worship. From the Aztecs, Mayans and Incas to the ancient Sumerians, Egyptians, Greeks, Romans and Druids, the Sun was a central deity because it was seen as the bringer of all light and life. In time, our understanding of the Sun has changed and become increasingly empirical. But that has done nothing to diminish it’s significance.

Continue reading “The Sun”

August 5, 2015December 23, 2015 by Ken Kremer

Moon Transits Earth in Eye-poppingly EPIC View from 1 Million Miles Away

This animation shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth – one million miles away. Credit: NASA/NOAA
See YouTube version and EPIC camera below[/caption]

An eye-poppingly ‘EPIC’ view of the sunlit far side of the Moon transiting the sunlit side of Earth was recently captured by NASA’s Earth Polychromatic Imaging Camera (EPIC) camera from one million miles away. “Wow!” – is an understatement!

The stunning animation of the Moon crossing in front of the Earth, shown above, and seemingly unlike anything else, was created from a series of images taken in July by NASA’s EPIC camera flying aboard the orbiting Deep Space Climate Observatory (DSCOVR), a space weather monitoring satellite, according to a NASA statement.

Have just witnessed NASA’s New Horizons flyby of the Pluto-Charon double planet system, the similarity to what some call the Earth-Moon double planet system is eerie. You could imagine ones heart going out to Earth’s Australian continent as an upside down version of Pluto’s bright heart shaped ‘Tombaugh Regio’ region in the southern hemisphere.

EPIC is a four megapixel CCD camera and telescope mounted on DSCOVR and orbiting at the L1 Lagrange Point – a neutral gravity point that lies on the direct line between Earth and the sun.

The goal of the $340 million DSCOVR is to monitor the solar wind and aid very important forecasts of space weather at Earth from L1.

EPIC will capture “a constant view of the fully illuminated Earth as it rotates, providing scientific observations of ozone, vegetation, cloud height and aerosols in the atmosphere.”

L1 is located 1.5 million kilometers (932,000 miles) sunward from Earth. At L1 the gravity between the sun and Earth is perfectly balanced and the DSCOVR satellite orbits about that spot just like a planet.

The EPIC images “were taken between 3:50 p.m. and 8:45 p.m. EDT on July 16, showing the moon moving over the Pacific Ocean near North America,” NASA said.

This image shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth - one million miles away. Credits: NASA/NOAA — This image shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth – one million miles away. Credits: NASA/NOAA

You can see Earth’s North Pole at the upper left side of the images which results from the orbital tilt of Earth from the vantage point of the spacecraft at the L1 Lagrange Point.

EPIC will take full disk color images of the sunlit side of Earth at least six times per day.

They will be made publically available by NASA at a dedicated website, when the camera starts its regular daily science observation campaign of the home planet in about a month during September.

NASA says the images will show varying views of the rotating Earth and they will be posted online some 12 to 36 hours after they are acquired.

Each image is actually a composite of three images taken in the red, green and blue channels of the EPIC camera to provide the final “natural color” image of Earth. Since the images are taken about 30 seconds apart as the moon is moving there is a slight but noticeable artifact on the right side of the moon, NASA explained.

Altogether, “ EPIC takes a series of 10 images using different narrowband spectral filters — from ultraviolet to near infrared — to produce a variety of science products. The red, green and blue channel images are used in these color images.”

EPIC should capture these Earth-Moon transits about twice per year as the orbit of DSCOVR crosses the orbital plane of the moon.

The closest analog according to NASA came in May 2008 when NASA’s Deep Impact spacecraft “captured a similar view of Earth and the moon from a distance of 31 million miles away. The series of images showed the moon passing in front of our home planet when it was only partially illuminated by the sun.”

We never see the far side of the moon from Earth since the bodies are tidally locked. And its quite apparent from the images, that the moon’s far side looks completely different from the side facing Earth. The far side lacks the large, dark, basaltic plains, or maria, that are so prominent on the Earth-facing side.

“It is surprising how much brighter Earth is than the moon,” said Adam Szabo, DSCOVR project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement.

“Our planet is a truly brilliant object in dark space compared to the lunar surface.”

DSCOVR is a joint mission between NOAA, NASA, and the U.S Air Force (USAF) that is managed by NOAA. The satellite and science instruments were provided by NASA and NOAA.

Technician works on NASA Earth science instruments and Earth imaging EPIC camera (white circle) housed on NOAA/NASA Deep Space Climate Observatory (DSCOVR) inside NASA Goddard Space Flight Center clean room in November 2014. Credit: Ken Kremer/kenkremer.com/AmericaSpace — Technician works on NASA Earth science instruments and Earth imaging EPIC camera (white circle) housed on NOAA/NASA Deep Space Climate Observatory (DSCOVR) inside NASA Goddard Space Flight Center clean room in November 2014. Credit: Ken Kremer/kenkremer.com

The couch sized probe was launched atop a SpaceX Falcon 9 on Feb. 11, 2015 from Cape Canaveral, Florida, to start a million mile journey to its deep space observation post. The rocket was funded by the USAF.

DSCOVR was first proposed in 1998 by then US Vice President Al Gore as the low cost ‘Triana’ satellite to take near continuous views of the Earth’s entire globe to feed to the internet as a means of motivating students to study math and science. It was eventually built as a much more capable Earth science satellite that would also conduct the space weather observations.

But Triana was shelved for purely partisan political reasons and the satellite was placed into storage at NASA Goddard and the science was lost until now.

It was also dubbed “Goresat.’

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

Video caption: This animation shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth – one million miles away. Credit: NASA/NOAA

NOAA/NASA Deep Space Climate Observatory (DSCOVR) undergoes processing in NASA Goddard Space Flight Center clean room. Solar wind instruments at right. DSCOVER will launch in February 2015 atop SpaceX Falcon 9 rocket. Credit: Ken Kremer/kenkremer.com/AmericaSpace — NOAA/NASA Deep Space Climate Observatory (DSCOVR) undergoes processing in NASA Goddard Space Flight Center clean room. Solar wind instruments at right. DSCOVER launched in February 2015 atop SpaceX Falcon 9 rocket. Credit: Ken Kremer/kenkremer.com

Launch of NOAA DSCOVR satellite from Cape Canaveral Air Force Station on Feb. 11, 2015 to monitor solar storms and space weather. Credit: Julian Leek

March 17, 2015December 23, 2015 by Bob King

Green and Red Auroras Light Up St. Patrick’s Day Dawn

Just in time for St. Patrick's Day - a — A spectacular green and red aurora photographed early this morning March 17, 2015, from Donnelly Creek, Alaska. Credit: Sebastian Saarloos

A strong G3 geomagetic storm surged across the planet this morning producing a spectacular display of the northern lights. Some of you may who may have risen to see the new nova were no doubt as surprised as the NOAA space weather folks, whose overnight forecast did not include an alert for even a minor storm.

So what happened? Let’s just say the Sun isn’t always as predictable as we’d like. An interplanetary shock wave in the form of a sudden increase in the solar wind speed from 250 miles per second to 375 mph (400-600 km/sec) began blasting Earth shortly before midnight. It appears the combined effects of earlier coronal mass ejections (CMEs) and an outpouring of high-speed solar particles from a gaping hole in the Sun’s magnetic canopy crashed through Earth’s magnetic defenses.

Particle-wise, all hell broke loose. You can start looking for more as soon as it gets dark tonight.

A powerful X2.2-class flare from sunspot region 2297 glows fiery yellow in this photo taken by NASA’s Solar Dynamics Observatory on March 11, 2015. Credit: NASA — A powerful X2.2-class flare from sunspot region 2297 glows intensely in this photo taken in short wavelength ultraviolet light by NASA’s Solar Dynamics Observatory on March 11, 2015. Credit: NASA Goddard SDO

We know that recent flares from sunspot group 2297 have sent more than a few billows of solar particles our way called CMEs or coronal mass ejections. Weekend forecasts called for minor storms but little materialized. Only when we thought it was safe to go back to bed did the aurora pounce. Reading the magnetospheric tea leaves, better known as the Kp index, a measure of magnetic activity high overhead in Earth’s ionosphere, quiet conditions gave way to auroral abandon starting around 1 a.m (CDT) today.

A wall of colorful red and green aurora met the eye and camera of Jim Schaff of Duluth this morning around 3 a.m. CDT. Credit: Jim Schaff

Like a spring grassfire the northern lights took off from there and burned till dawn, peaking between 2 and 4 a.m. Most of us are usually asleep during those deep hours of the night, but I’m hoping those who arose to see the nova or catch the lunar crescent at dawn may have been as surprised and delighted as I was to see auroras.

Like paw prints made by a cat, pale green auroral rays mark the northern sky around 5:45 a.m this morning March 17. Credit: Bob King

More are in the offing. The latest space weather forecast calls for continued severe storms (G3 or higher) to continue through tonight. G1 or minor storms are normally only visible as arcs or low rays across the north from the northern tier of states, but if tonight’s forecast holds, a fair portion of the U.S. should see auroras. Keep an eye peeled for bright, moving glow and arcs across the northern sky.

The awesome 30-minute aurora forecast map updates the shrinking and expanding of Earth's northern auroral oval due to changes in the solar wind from CMEs, flares and the like. This view is from this morning around 4:55 a.m. Red indicates intense aurora. Credit: NOAA — The awesome 30-minute aurora forecast map updates the shrinking and expanding of Earth’s northern auroral oval due to changes in the solar wind from CMEs, flares and the like. This view is from this morning around 4:55 a.m. Red indicates intense aurora. Credit: NOAA

There are lots of tools available you can use yourself to know if auroras are lurking about. First, check the NOAA 3-day space weather forecast. There you’ll see a list of times along with a Kp index number indicating magnetic activity. Number “1-4” means no storm and little likelihood you’ll see an aurora. “5” indicates a minor storm; the higher the number the more severe the storm and more widespread the northern lights will be.

Curtains of aurora still pushed through the growing light of dawn. Credit: Bob King — Curtains of aurora still pushed through the growing light of dawn (blue sky at top). Credit: Bob King

There’s also a nice visual representation of the numbers on the Planetary K-index site, where magnetic activity is updated every 3 hours. The dashed line on the bar chart represents 0 UT or 7 p.m. CDT. One of my favorites and the ultimate visual feast of an aurora indicator is NOAA’s Aurora 30-minute Forecast. Here you get a birds-eye representation of the current aurora based on satellite data. When the permanent auroral oval expands southward and intensifies, put on your coat and head out for a look. For education and entertainment, click on the gray arrow below the graphic and you’ll see a whole day’s worth of activity play out before your eyes. Totes cool.

ACE plot from a June 2013 aurora. Note the steep drop in the Bz. Credit: NOAA — ACE plot from a June 2013 aurora. Note the steep drop in the Bz. ACE orbits around the L1 Lagrange point about a million miles ahead of Earth in the direction of the Sun. There it studies the incoming particle streams from the Sun hours before they reach Earth. Credit: NOAA

I’m also in big believer in the the Advanced Composition Explorer (ACE) Bz plot. Bz is the direction of the embedded solar magnetic field that gift-wraps the streams of high-speed particles sent our way by the Sun. Like a magnet, it has a south pole and a north pole. When the south pole of the field sweeps by – what scientists call a negative Bz – the blast is more likely to link up with Earth’s magnetic field and spark auroras. When you see the Bz “head south” to -5 or lower, there’s a chance for auroras.

Now that you’re armed with information, cross your fingers all the indicators will point in the right direction for the aurora to continue tonight. And yes, Happy St. Patrick’s Day!

Skiing stop to take in the northern lights near Fairbanks Monday night. Credit: John Chumack — Skywatchers stop to take in the northern lights near Fairbanks Monday night. Credit: John Chumack

UPDATE: The storm continues and is now rated G4 or severe as of 10 a.m. CDT. Lucky for you if you live somewhere where it’s dark right now.