Meet Steve, A Most Peculiar Aurora

Nicknamed Steve, this unusual aurora feature is a 15.5-mile-wide (25 km) ribbon of hot gas flowing westward at about 13,300 mph, more than 600 times faster than the surrounding air. The photo was taken last fall. Copyright: Instagram.com/davemarkelphoto

This remarkable image was captured last fall by Dave Markel, a photographer based in Kamloops, British Columbia. Later, aurora researcher Eric Donovan of the University of Calgary, discovered Markel’s strange ribbon of light while looking through photos of the northern lights on social media. Knowing he’d found something unusual, Donovan worked sifted through data from the European Space Agency’s Swarm magnetic field mission to try and understand the nature of the phenomenon.

Swarm is ESA’s first constellation of Earth observation satellites designed to measure the magnetic signals from Earth’s core, mantle, crust, oceans, ionosphere and magnetosphere, providing data that will allow scientists to study the complexities of our protective magnetic field. Credit: ESA/AOES Medialab

Launched on 22 November 2013, three identical Swarm satellites orbit the Earth measuring the magnetic fields that stem from Earth’s core, mantle, crust and oceans, as well as from the ionosphere and magnetosphere. Speaking at the recent Swarm science meeting in Canada, Donovan explained how this new finding couldn’t have happened 20 years ago when he started to study the aurora.

A beautiful aurora featuring green arcs near the horizon and many parallel rays lights up the northern sky last October. A small meteor appears to the right of center. Credit: Bob King

While the shimmering, eerie, light display of auroras might be beautiful and captivating, they’re also a visual reminder that Earth is connected electrically and magnetically to the Sun. The more we know about the aurora, the greater our understanding of that connection and how it affects everything from satellites to power grids to electrically-induced corrosion of oil pipelines.

“In 1997 we had just one all-sky imager in North America to observe the aurora borealis from the ground,” said Prof. Donovan.  “Back then we would be lucky if we got one photograph a night of the aurora taken from the ground that coincides with an observation from a satellite. Now we have many more all-sky imagers and satellite missions like Swarm so we get more than 100 a night.”

The Suomi NPP satellite photographed this view of the aurora on December 22, 2016, when the northern lights stretched across northern Canada. Credit: NASA Earth Observatory image by Jesse Allen / Suomi National Polar-orbiting Partnership. Colorized and labeled by the author

And that’s where sharing photos and observations on social media can play an important role. Sites like the Great Lakes Aurora Hunters and Aurorasaurus serve as clearinghouses for observers to report auroral displays.  Aurorasaurus connects citizen scientists to scientists and searches Twitter feeds for instances of the word ‘aurora,’ so skywatchers and scientists alike know the real-time extent of the auroral oval.

At a recent talk, Prof. Donovan met members the popular Facebook group Alberta Aurora Chasers. Looking at their photos, he came across the purple streak Markel and others had photographed which they’d been referring to as a “proton arc.” But such a feature, caused by hydrogen emission in the upper atmosphere, is too faint to be seen with the naked eye. Donovan knew it was something else, but what?Someone suggested “Steve.” Hey, why not?

Aurora researchers now us a network of all-sky cameras and multiple satellites to keep track of the ever-shifting aurora. Click to see the video. Credit: University of Calgary

While the group kept watch for the Steve’s return,  Donovan and colleagues looked through data from the Swarm mission and his network of all-sky cameras. Before long he was able to match a ground sighting of streak to an overpass of one of the three Swarm satellites.

“As the satellite flew straight though Steve, data from the electric field instrument showed very clear changes,” said Donovan.

“The temperature 186 miles (300 km) above Earth’s surface jumped by 3000°C and the data revealed a 15.5-mile-wide (25 km) ribbon of gas flowing westwards at about 6 km/second compared to a speed of about 10 meters/second either side of the ribbon. A friend of mine compared it to a fluorescent light without the glass.

Little did I know I’d met Steve back on May 18, 1990 in this remarkable, narrow arc that stretched from the northwestern horizon to the southeastern. To the eye, a “wind” of vague forms pulsed through the arc. The Big Dipper stands vertically at right. Credit: Bob King

It turns out that these high-speed “rivers” of glowing auroral gas are much more common than we’d thought, and that in no small measure because of the efforts of an army of skywatchers and aurora photographers who keep watch for that telltale green glow in the northern sky.

I spoke to Steve’s keeper, Dave Markel, via e-mail yesterday and he described what the arc looked like to his eyes:

“It’s similar to the image just not as intense. It looks like a massive contrail moving rapidly across the sky. This one lasted almost an hour and ran in an arc almost perfectly east to west. I was directly below it but often there are green pickets (parallel streaks of aurora) rising above the streak.”

This is the same May 18, 1990 streak as above but the eastern half. The bright star Arcturus is visible at upper right. Wish I’d had a fisheye! Credit: Bob King

I know whereof Dave speaks because thanks to his photo and Prof. Donovan’s research, I realize I’ve seen and photographed Steve, too! In decades of aurora watching I’ve only seen this rare streak a handful of times. On most of those occasions, there was either no other aurora visible or minor activity in the northern sky. The narrow arc, which lasted for an hour or so, pulsed and flowed with light and occasionally, Markel’s “pickets” were visible. Back in May 1990 I had a camera on hand to get a picture.

Goes to show, you never know what you might see when you poke your head out for a look. Keep a lookout when aurora’s expected and maybe you’ll get to meet Steve, too.

Hubble Sees Intense Auroras on Uranus

This is a composite image of Uranus by Voyager 2 and two different observations made by Hubble — one for the ring and one for the auroras. These auroras occurred in the planet’s southern latitudes near the planet’s south magnetic pole. Like Jupiter and Saturn, hydrogen atoms excited by blasts of the solar wind are the cause for the glowing white patches seen in both photos. Credit: NASA/ESA

Earth doesn’t have a corner on auroras. Venus, Mars, Jupiter, Saturn, Uranus and Neptune have their own distinctive versions. Jupiter’s are massive and powerful; Martian auroras patchy and weak.

Auroras are caused by streams of charged particles like electrons that originate with solar winds and in the case of Jupiter, volcanic gases spewed by the moon Io. Whether solar particles or volcanic sulfur, the material gets caught in powerful magnetic fields surrounding a planet and channeled into the upper atmosphere. There, the particles interact with atmospheric gases such as oxygen or nitrogen and spectacular bursts of light result. With Jupiter, Saturn and Uranus excited hydrogen is responsible for the show.

These composite images show Uranian auroras, which scientists caught glimpses of through the Hubble in 2011. In the left image, you can clearly see how the aurora stands high above the planet’s denser atmosphere. These photos combine Hubble pictures made in UV and visible light by Hubble with photos of Uranus’ disk from the Voyager 2 and a third image of the rings from the Gemini Observatory in Hawaii and Chile. The auroras are located close to the planet’s north magnetic pole, making these northern lights.
Credit: NASA, ESA, and L. Lamy (Observatory of Paris, CNRS, CNES)

Auroras on Earth, Jupiter and Saturn have been well-studied but not so on the ice-giant planet Uranus. In 2011, the Hubble Space Telescope took the first-ever image of the auroras on Uranus. Then in 2012 and 2014 a team from the Paris Observatory took a second look at the auroras in ultraviolet light using the Space Telescope Imaging Spectrograph (STIS) installed on Hubble.

From left: Auroras on Earth (southern auroral oval is seen over Antarctica), Jupiter and Saturn. In each case, the rings of permanent aurora are centered on their planets’ magnetic poles which aren’t too far from the geographic poles, unlike topsy-turvy Uranus. Credit: NASA

Two powerful bursts of solar wind traveling from the sun to Uranus stoked the most intense auroras ever observed on the planet in those years. By watching the auroras over time, the team discovered that these powerful shimmering regions rotate with the planet. They also re-discovered Uranus’ long-lost magnetic poles, which were lost shortly after their discovery by Voyager 2 in 1986 due to uncertainties in measurements and the fact that the planet’s surface is practically featureless. Imagine trying to find the north and south poles of a cue ball. Yeah, something like that.

In both photos, the auroras look like glowing dots or patchy spots. Because Uranus’ magnetic field is inclined 59° to its spin axis (remember, this is the planet that rotates on its side!) , the auroral spots appear far from the planet’s north and south geographic poles. They almost look random but of course they’re not. In 2011, the spots lie close to the planet’s north magnetic pole, and in 2012 and 2014, near the south magnetic pole — just like auroras on Earth.

An auroral display can last for hours here on the home planet, but in the case of the 2011 Uranian lights, they pulsed for just minutes before fading away.

Want to know more? Read the team’s findings in detail here.

NASA Fires a Rocket into the Northern Lights, for Science!

Not only is it aurora season in Alaska, its sounding rocket season! NASA started launching a series of five sounding rockets from the Poker Flat Research Range in Alaska to study the aurora. The first of these rockets for this year, a Black Brant IX, was launched in the early morning hours of February 22, 2017.

The instrument on board was an Ionospheric Structuring: In Situ and Groundbased Low Altitude StudieS (ISINGLASS) instrumented payload, which studies the structure of an aurora.

The Black Brant IX sounding rocket carried instruments to an altitude of 225 miles as part of the Ionospheric Structuring: In Situ and Groundbased Low Altitude StudieS or ISINGLASS mission. Credit: NASA/Terry Zaperach.

This is not the first sounding rocket flight from Poker Flats to launch into an aurora. Starting in 2009, this research has been taking place to help refine current models of aurora structure, and provide insight on the high-frequency waves and turbulence generated by aurorae. This helps us to better understand the space weather caused by the charged particles that come from the Sun and how it impacts Earth’s lower atmosphere and ionosphere.

“The visible light produced in the atmosphere as aurora is the last step of a chain of processes connecting the solar wind to the atmosphere,” said Kristina Lynch, ISINGLASS principal investigator from Dartmouth College. “We are seeking to understand what structure in these visible signatures can tell us about the electrodynamics of processes higher up.”

While humans don’t feel any of these effects directly, the electronic systems in our satellites do, and as our reliance on satellite technologies grow, researchers want to have all the data they can to help avert problems than can be caused by space weather.

The rocket sent a stream of real-time data back before landing about 200 miles downrange shortly after the launch.

The launch window for the remaining rockets runs through March 3. ISINGLASS will fly into what is known as a dynamic Alfenic curtain, which is a form of electromagnetic energy thought to be a key driver of “discrete” aurora – the typical, well-defined band of shimmering lights about six miles thick and stretching east to west from horizon to horizon.

NASA says that the five launches in the 2017 sounding rocket campaign will add to our body of information about this space through which our spacecraft and astronauts travel near Earth. By studying the interaction of the sun and its solar wind with Earth’s upper atmosphere, scientists are also able to apply the knowledge to other planetary bodies — helping us understand these interactions throughout the universe as well.

Here’s an infographic from NASA about the 2017 sounding rocket launches from Poker Flats:

Read more: NASA

What Was the Carrington Event?

What Was The Carrington Event?

Isn’t modern society great? With all this technology surrounding us in all directions. It’s like a cocoon of sweet, fluffy silicon. There are chips in my fitness tracker, my bluetooth headset, mobile phone, car keys and that’s just on my body.

At all times in the Cain household, there dozens of internet devices connected to my wifi router. I’m not sure how we got to the point, but there’s one thing I know for sure, more is better. If I could use two smartphones at the same time, I totally would.

And I’m sure you agree, that without all this technology, life would be a pale shadow of its current glory. Without these devices, we’d have to actually interact with each other. Maybe enjoy the beauty of nature, or something boring like that.

It turns out, that terrible burning orb in the sky, the Sun, is fully willing and capable of bricking our precious technology. It’s done so in the past, and it’s likely to take a swipe at us in the future.

I’m talking about solar storms, of course, tremendous blasts of particles and radiation from the Sun which can interact with the Earth’s magnetosphere and overwhelm anything with a wire.

Credit: NASA

In fact, we got a sneak preview of this back in 1859, when a massive solar storm engulfed the Earth and ruined our old timey technology. It was known as the Carrington Event.

Follow your imagination back to Thursday, September 1st, 1859. This was squarely in the middle of the Victorian age.

And not the awesome, fictional Steampunk Victorian age where spectacled gentleman and ladies of adventure plied the skies in their steam-powered brass dirigibles.

No, it was the regular crappy Victorian age of cholera and child labor. Technology was making huge leaps and bounds, however, and the first telegraph lines and electrical grids were getting laid down.

Imagine a really primitive version of today’s electrical grid and internet.

On that fateful morning, the British astronomer Richard Carrington turned his solar telescope to the Sun, and was amazed at the huge sunspot complex staring back at him. So impressed that he drew this picture of it.

Richard Carrington’s sketch of the sunspots seen just before the 1859 Carrington event.

While he was observing the sunspot, Carrington noticed it flash brightly, right in his telescope, becoming a large kidney-shaped bright white flare.

Carrington realized he was seeing unprecedented activity on the surface of the Sun. Within a minute, the activity died down and faded away.

And then about 5 minutes later. Aurora activity erupted across the entire planet. We’re not talking about those rare Northern Lights enjoyed by the Alaskans, Canadians and Northern Europeans in the audience. We’re talking about everyone, everywhere on Earth. Even in the tropics.

In fact, the brilliant auroras were so bright you could read a book to them.

The beautiful night time auroras was just one effect from the monster solar flare. The other impact was that telegraph lines and electrical grids were overwhelmed by the electricity pushed through their wires. Operators got electrical shocks from their telegraph machines, and the telegraph paper lit on fire.

What happened? The most powerful solar flare ever observed is what happened.

In this image, the Solar Dynamics Observatory (SDO) captured an X1.2 class solar flare, peaking on May 15, 2013. Credit: NASA/SDO

A solar flare occurs because the Sun’s magnetic field lines can get tangled up in the solar atmosphere. In a moment, the magnetic fields reorganize themselves, and a huge wave of particles and radiation is released.

Flares happen in three stages. First, you get the precursor stage, with a blast of soft X-ray radiation. This is followed by the impulsive stage, where protons and electrons are accelerated off the surface of the Sun. And finally, the decay stage, with another burp of X-rays as the flare dies down.

These stages can happen in just a few seconds or drag out over an hour.

Remember those particles hurled off into space? They take several hours or a few days to reach Earth and interact with our planet’s protective magnetosphere, and then we get to see beautiful auroras in the sky.

This geomagnetic storm causes the Earth’s magnetosphere to jiggle around, which drives charges through wires back and forth, burning out circuits, killing satellites, overloading electrical grids.

Back in 1859, this wasn’t a huge deal, when our quaint technology hadn’t progressed beyond the occasional telegraph tower.

Today, our entire civilization depends on wires. There are wires in the hundreds of satellites flying overhead that we depend on for communications and navigation. Our homes and businesses are connected by an enormous electrical grid. Airplanes, cars, smartphones, this camera I’m using.

Credit: Wikimedia Commons.

Everything is electronic, or controlled by electronics.

Think it can’t happen? We got a sneak preview back in March, 1989 when a much smaller geomagnetic storm crashed into the Earth. People as far south as Florida and Cuba could see auroras in the sky, while North America’s entire interconnected electrical grid groaned under the strain.

The Canadian province of Quebec’s electrical grid wasn’t able to handle the load and went entirely offline. For 12 hours, in the freezing Quebec winter, almost the entire province was without power. I’m telling you, that place gets cold, so this was really bad timing.

Satellites went offline, including NASA’s TDRS-1 communication satellite, which suffered 250 separate glitches during the storm.

And on July 23, 2012, a Carrington-class solar superstorm blasted off the Sun, and off into space. Fortunately, it missed the Earth, and we were spared the mayhem.

If a solar storm of that magnitude did strike the Earth, the cleanup might cost $2 trillion, according to a study by the National Academy of Sciences.

The July 23, 2012 CME would have caused a Carrington-like event had it hit Earth. Thankfully for us and our technology, it missed. Credit: NASA’s Goddard Space Flight Center

It’s been 160 years since the Carrington Event, and according to ice core samples, this was the most powerful solar flare over the last 500 years or so. Solar astronomers estimate solar storms like this happen twice a millennium, which means we’re not likely to experience another one in our lifetimes.

But if we do, it’ll cause worldwide destruction of technology and anyone reliant on it. You might want to have a contingency plan with some topic starters when you can’t access the internet for a few days. Locate nearby interesting nature spots to explore and enjoy while you wait for our technological civilization to be rebuilt.

Have you ever seen an aurora in your lifetime? Give me the details of your experience in the comments.

What My Dog Taught Me About Time and Space

Sammy and her namesake, Sirius the Dog Star, on a winter night. Photos by the author

Like many of you, I’m the owner of a furry Canis Major. Her name is Sammy. We always thought she was mostly border collie, but my daughter gifted me with a doggie DNA kit a few years back, and now we know with scientific certainty that she’s a mix of German shepherd, Siberian husky and golden retriever. Yeah, she’s a mutt.

Sammy’s going on 17 years old now — that’s human years — and has neither the spunk nor bladder control of a young pup. She wanders, paces, gets confused. In her aging, I see what’s in store for all of us as we pass from one stage of life to the next.

Intentionally or not, we humans often leave a legacy before we depart. Maybe a big building, a work of art or an exemplary life. As I stare down at my panting dog, it occurs that she’s leaving a legacy too, one she’s completely unaware of but which I’ll always appreciate.

Thanks to my dog I’ve seen more auroras and lunar halos that I can count. That goes for meteors, contrails, space station passes, light pillars and moonrises, too. All this because she needs to be walked in the early morning and again at night. This simple act ensures that while Sammy sniffs and marks, I get to spend at least 20 minutes under the sky. Nearly every night of the year.

Warm under her thick coat, she’s not bothered by the snow.

I’m an amateur astronomer and keep tabs on what’s up, but my dog makes sure I don’t ignore the sky. Let’s say she keeps me honest. There’s no avoiding going out or I’ll pay for it in whimpering and cleanup.

There were times I wouldn’t be aware an aurora was underway until it was time to walk the dog. When we were done, I’d dash away to a dark sky with camera and tripod. Other nights, walking the dog would alert me to a sudden clearing and the opportunity to catch a variable star on the rise or see a newly discovered comet for the first time. Thanks Sammy.

Amateur astronomers are familiar with eternity. We routinely observe stars and galaxies by eye and telescope that remind us of both the vastness of space and the aching expanse of time. I have only so many years left before I spend the next 10 billion years disassembled and strewn about like that scarecrow attacked by flying monkeys. But when I see the Sombrero Galaxy through my telescope, with its 29-million-year-old photons setting off tiny explosions in my retinas, I get a taste of eternity in the here and now.

That’s where Sammy offers yet another pearl. Dogs are far better living in the moment than people are. They can eat the same food twice a day for a decade and relish it anew every single time. Same goes for their excitement at seeing their owner or taking a walk or a million other ways they reveal that this moment is what counts.

The famous Sombrero galaxy (M104) is a bright nearby spiral galaxy. The prominent dust lane and halo of stars and globular clusters give this galaxy its name. Credit: NASA/ESA and The Hubble Heritage Team (STScI/AURA)

People tend to think of eternity as encompassing all of time, but Sammy has a different take. A moment fully experienced feels like it might never end. Lose yourself in the moment, and the clock stops ticking. I love that feeling. That’s how my dog’s been living all along. Canine wisdom: one billion years = one moment. Both feel like forever.

Sammy’s lost much of her hearing and some of her eyesight. We’re not sure how long she has. Maybe a few months, maybe even another year, but her legacy is clear. She’s been a great pet and teacher even if she never figured out how to fetch. We’ve hiked hard trails together and then rested atop precipices with the sun sinking in the west. I look into her clouded eyes these days and have to speak up when I call her name, but she’s been and remains a “Good dog!”

Northern Lights by Drone? You Won’t Believe Your Eyes


Northern lights over Iceland filmed by Icelandic photographer Oli Haukur using a drone. Don’t forget to expand the screen.

I knew the era of real-time northern lights video was upon us. I just didn’t think drones would get into the act this soon. What was I thinking? They’re perfect for the job! If watching the aurora ever made you feel like you could fly, well now you can in Oli Haukur’s moving, real-time footage of an amazing aurora display filmed by drone.

Oli Haukur operates the drone and camera during a test run. Credit: Oli Hauku / OZZO Photography
Oli Haukur operates the drone and camera during a test run. Credit: Oli Hauku / OZZO Photography

Haukur hooked up a Sony a7S II digital camera and ultra-wide Sigma 20mm f/1.4 lens onto his DJI Matrice 600 hexacopter. The light from the gibbous moon illuminates the rugged shoreline and crashing waves of the Reykjanes Peninsula (The Steamy Peninsula) as while green curtains of aurora flicker above.

The Sony camera is shown attached to the drone. To capture the aurora, Haukur used a fast lens, high ISO and set the frame rate to 25 frames per second (fps) or 1/25th of a second per frame. Credit: Oli Haukur / OZZO Photography
The Sony camera is shown attached to the drone. To capture the aurora, Haukur used a fast lens, high ISO and set the frame rate to 25 frames per second (fps) or 1/25th of a second per frame. Credit: Oli Haukur / OZZO Photography

When the camera ascends over a sea stack, you can see gulls take off below, surprised by the mechanical bird buzzing just above their heads. Breathtaking. You might notice at the same time a flash of light — this is from the lighthouse beacon seen earlier in the video.

To capture his the footage, Haukur used a “fast” lens (one that needs only a small amount of light to make a picture) and an ISO of 25,600. The camera is capable of ISO 400,000, but the lower ISO provided greater resolution and color quality.

Moonlight provided all the light needed to bring out the landscape.

The drone used to make the night flight. Credit: Oli Haukur
The drone used to make the night flight and aurora recording is seen up close on takeoff. Haukur, of Rejkyavik, Iceland, works as a freelance photographer and filmmaker as well as providing professional drone services in that country. Credit: Oli Haukur / OZZO Photography

Remember when ISO 1600 or 3200 was as far you dared to go before the image turned to a grainy mush? Last year Canon released a camera that can literally see in the dark with a top ISO over 4,000,000! There’s no question we’ll be seeing more live aurora and drone aurora video in the coming months. Haukur plans additional shoots this winter and early next spring. Living in Iceland, which lies almost directly beneath the permanent auroral oval, you can schedule these sort of things!

Am I allowed one tiny criticism? I want more — a minute and a half is barely enough! Haukur shot plenty but released only a taste to social media to prove it could be done and share the joy. Let’s hope he compiles the rest and makes it available for us to lose our selves in soon.

Space Weather Causing Martian Atmospherics

A curious plume-like feature was observed on Mars on 17 May 1997 by the Hubble Space Telescope. It is similar to the features detected by amateur astronomers in 2012, although appeared in a different location. Credit: JPL/NASA/STScI
A curious plume-like feature was observed on Mars on May 17, 1997 by the Hubble Space Telescope. It is similar to the features detected by amateur astronomers in 2012, although appeared in a different location. Credit: JPL/NASA/STScI

Strange plumes in Mars’ atmosphere first recorded by amateur astronomers four year ago have planetary scientists still scratching their heads. But new data from European Space Agency’s orbiting Mars Express points to coronal mass ejections from the Sun as the culprit.

Mystery plume in Mars’ southern hemisphere photographed by amateur astronomer Wayne Jaeschke on March 20, 2012. The feature extended between 310-620 miles and lasted for about 10 days.
Mystery plume in Mars’ southern hemisphere photographed and animated by amateur astronomer Wayne Jaeschke on March 20, 2012. The feature lasted for about 10 days. Credit: Wayne Jaeschke

On two occasions in 2012 amateurs photographed cloud-like features rising to altitudes of over 155 miles (250 km) above the same region of Mars. By comparison, similar features seen in the past haven’t exceeded 62 miles (100 km). On March 20th of that year, the cloud developed in less than 10 hours, covered an area of up to 620 x 310 miles (1000 x 500 kilometers), and remained visible for around 10 days.

Back then astronomers hypothesized that ice crystals or even dust whirled high into the Martian atmosphere by seasonal winds might be the cause. However, the extreme altitude is far higher than where typical clouds of frozen carbon dioxide and water are thought to be able to form.

Indeed at those altitudes, we’ve entered Mars’ ionosphere, a rarified region where what air there is has been ionized by solar radiation. At Earth, charged particles from the Sun follow the planet’s global magnetic lines of force into the upper atmosphere to spark the aurora borealis. Might the strange features observed be Martian auroras linked to regions on the surface with stronger-than-usual magnetic fields?

Mars has magnetized rocks in its crust that create localized, patchy magnetic fields (left). In the illustration at right, we see how those fields extend into space above the rocks. At their tops, auroras can form. Credit: NASA
Mars has magnetized rocks in its crust that create localized, patchy magnetic fields (left). In the illustration at right, we see how those fields extend into space above the rocks. At their tops, auroras can form. Credit: NASA

Once upon a very long time ago, Mars may have had a global magnetic field generated by electrical currents in a liquid iron-nickel core much like the Earth’s does today. In the current era, the Red Planet has only residual fields centered over regions of magnetic rocks in its crust.

Copyright: W. Jaeschke and D. Parker The top image shows the location of the mysterious plume on Mars, identified within the yellow circle (top image, south is up), along with different views of the changing plume morphology taken by W. Jaeschke and D. Parker on 21 March 21 2012.
The top image shows the location of the mysterious plume on Mars, identified within the yellow circle (top image, south is up), along with different views of the changing plume morphology on March 21, 2012. Copyright: W. Jaeschke and D. Parker

Instead of a single, planet-wide field that funnels particles from the Sun into the atmosphere to generate auroras, Mars is peppered with pockets of magnetism, each potentially capable of connecting with the wind of particles from the Sun to spark a modest display of the “northern lights.” Auroras were first discovered on Mars in 2004 by the Mars Express orbiter, but they’re faint compared to the plumes, which were too bright to be considered auroras.

Still, this was a step in the right direction. What was needed was some hard data of a possible Sun-Earth interaction which scientists ultimately found when they looked into plasma and solar wind measurements collected by Mars Express at the time. David Andrews of the Swedish Institute of Space Physics, lead author of a recent paper reporting the Mars Express results, found evidence for a large coronal mass ejection or CME from the Sun striking the martian atmosphere in the right place and at around the right time.

Examples of Earth-based observations of the mysterious plume seen on 21 March 2012 (top right) and of Mars Express solar wind observations during March and April 2012 (bottom right).
Earth-based observations of the plume on March 21, 2012 (top right) and of Mars Express solar wind observations during March and April 2012 (bottom right). The left-hand graphics show Mars as seen by Mars Express. Green represents the planet’s dayside and gray, the nightside. Magnetic areas of the crust are shown in blue and red. The white box indicates the area in which the plume observations were made. Together, these graphics show that the amateur observations were made during the martian daytime, along the dawn terminator, while the spacecraft observations were made along the dusk terminator, approximately half a martian ‘day’ later.The black line on Mars is the ground track of the Mars Express orbiter. The plot on the lower right shows Mars Express’s solar wind measurements. The peaks marked by the horizontal blue line indicate the increase in the solar wind properties as a result of the impact of the coronal mass ejection. Credit: Copyright: visual images: D. Parker (large Mars image and bottom inset) & W. Jaeschke (top inset). All other graphics courtesy D. Andrews

CMEs are enormous explosions of hot solar plasma — a soup of electrons and protons — entwined with magnetic fields that blast off the Sun and can touch off geomagnetic storms and auroras when they encounter the Earth and other planets.

“Our plasma observations tell us that there was a space weather event large enough to impact Mars and increase the escape of plasma from the planet’s atmosphere,” said Andrews. Indeed, the plume was seen along the day–night boundary, over a region of known strong crustal magnetic fields.

Locations of 19 auroral detections (white circles) made by the SPICAM instrument on Mars Express during 113 nightside orbits between 2004 and 2014, over locations already known to be associated with residual crustal magnetism. The data is superimposed on the magnetic field line structure (from NASA’s Mars Global Surveyor) where red indicates closed magnetic field lines, grading through yellow, green and blue to open field lines in purple. The auroral emissions are very short-lived, they are not seen to repeat in the same locations, and only occur near the boundary between open and closed magnetic field lines. Credit: ESA / Copyright Based on data from J-C. Gérard et al (2015)
Locations of 19 auroral detections (white circles) made by Mars Express during 113 nightside orbits between 2004 and 2014, over locations already known to be associated with residual crustal magnetism. The data is superimposed on the magnetic field line structure (from NASA’s Mars Global Surveyor) where red indicates closed magnetic field lines, grading through yellow, green and blue to open field lines in purple. The auroral emissions are very short-lived, they are not seen to repeat in the same locations. Credit: ESA / Copyright Based on data from J-C. Gérard et al (2015)

But again, a Mars aurora wouldn’t be expected to shine so brightly. That’s why Andrews thinks that the CME prompted a disturbance in the ionosphere large enough to affect dust and ice grains below:

“One idea is that a fast-traveling CME causes a significant perturbation in the ionosphere resulting in dust and ice grains residing at high altitudes in the upper atmosphere being pushed around by the ionospheric plasma and magnetic fields, and then lofted to even higher altitudes by electrical charging,” according to Andrews.

A colossal CME departs the Sun in February 2000. erupting filament lifted off the active solar surface and blasted this enormous bubble of magnetic plasma into space. Credit NASA/ESA/SOHO
A colossal CME, composed of a magnetized cloud of subatomic particles, departs the Sun in February 2000. Credit NASA/ESA/SOHO

With enough dust and ice twinkling high above the planet’s surface, it might be possible for observers on Earth to see the result as a wispy plume of light. Plumes appear to be rare on Mars as a search through the archives has revealed. The only other, seen by the Hubble Space Telescope in May 1997, occurred when a CME was hitting the Earth at the same time. Unfortunately, there’s no information from Mars orbiters at the time about its effect on that planet.

Observers on Earth and orbiters zipping around the Red Planet continue to monitor Mars for recurrences. Scientists also plan to use the webcam on Mars Express for more frequent coverage. Like a dog with a bone, once scientists get a bite on a tasty mystery, they won’t be letting go anytime soon.

Give Mom the Aurora Tonight / Mercury Transit Update

Skywatchers across the northern tier of states, the Midwest and southern Canada were treated to a spectacular display of the aurora borealis last night. More may be on tap for tonight. Credit: Bob King
Skywatchers across the northern tier of states, the Midwest and southern Canada were treated to a spectacular display of the aurora borealis last night. More may be on tap for tonight — in honor of Mother’s Day of course! Credit: Bob King

Simple choices can sometimes lead to dramatic turns of events in our lives. Before turning in for the night last night, I opened the front door for one last look at the night sky. A brighter-than-normal auroral arc arched over the northern horizon. Although no geomagnetic activity had been forecast, there was something about that arc that hinted of possibility.

It was 11:30 at the time, and it would have been easy to go to bed, but I figured one quick drive north for a better look couldn’t hurt. Ten minutes later the sky exploded. The arc subdivided into individual pillars of light that stretched by degrees until they reached the zenith and beyond. Rhythmic ripples of light – much like the regular beat of waves on a beach — pulsed upward through the display. You can’t see a chill going up your spine, but if you could, this is what it would look like.

A coronal aurora twists overhead in this photo taken early on May 8 from near Duluth, Minn. Credit: Bob King
A coronal aurora twists overhead in this photo taken around 12:15 a.m. on May 8 from near Duluth, Minn. What this photo and the others don’t show is how fast parts of the display flashed and flickered. Shapes would form, disappear and reform in seconds. Credit: Bob King

Auroras can be caused by huge eruptions of subatomic particles from the Sun’s corona called CMEs or coronal mass ejections, but they can also be sparked by holes in the solar magnetic canopy. Coronal holes show up as blank regions in photos of the Sun taken in far ultraviolet and X-ray light. Bright magnetic loops restrain the constant leakage of electrons and protons from the Sun called the solar wind. But holes allow these particles to fly away into space at high speed. Last night’s aurora traces its origin back to one of these holes.

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
Both a bar magnet (left) and Earth are surrounded by magnetic fields with north and south poles. Earth’s field is shaped by charged particles – electrons and protons – flowing from the sun called the solar wind. Credit: Andy Washnik (left) and NASA

The subatomic particles in the gusty wind come bundled with their own magnetic field with a plus or positive pole and a minus or negative pole. Recall that an ordinary bar magnet also  has a “+” and “-” pole, and that like poles repel and opposite poles attract. Earth likewise has magnetic poles which anchor a large bubble of magnetism around the planet called the magnetosphere.

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

Field lines in the magnetosphere — those invisible lines of magnetic force around every magnet — point toward the north pole. When the field lines in the solar wind also point north, there’s little interaction between the two, almost like two magnets repelling one another. But if the cloud’s lines of magnetic force point south, they can link directly into Earth’s magnetic field like two magnets snapping together. Particles, primarily electrons, stream willy-nilly at high speed down Earth’s magnetic field lines like a zillion firefighters zipping down fire poles.  They crash directly into molecules and atoms of oxygen and nitrogen around 60-100 miles overhead, which absorb the energy and then release it moments later in bursts of green and red light.

View of the eastern sky during the peak of this morning's aurora. Credit: Bob King
View of the eastern sky during the peak of this morning’s aurora. Credit: Bob King

So do great forces act on the tiniest of things to produce a vibrant display of northern lights. Last night’s show began at nightfall and lasted into dawn. Good news! The latest forecast calls for another round of aurora tonight from about 7 p.m. to 1 a.m. CDT (0-6 hours UT). Only minor G1 storming (K index =5) is expected, but that was last night’s expectation, too. Like the weather, the aurora can be tricky to pin down. Instead of a G1, we got a G3 or strong storm. No one’s complaining.

So if you’re looking for that perfect last minute Mother’s Day gift, take your mom to a place with a good view of the northern sky and start looking at the end of dusk for activity. Displays often begin with a low, “quiet” arc and amp up from there.

The camera recorded pale purple and red but the primary color visible to the eye was green. Credit: Bob Kin
The camera recorded pale purple, red and green, but the primary color visible to the eye was green. Cameras capture far more color than what the naked eye sees because even faint colors increase in intensity during a time exposure. Details: ISO 800, f/2.8, 13 seconds. Credit: Bob King

Aurora or not, tomorrow features a big event many of us have anticipated for years — the transit of Mercury. You’ll find everything you’ll need to know in this earlier story, but to recap, Mercury will cross directly in front of the Sun during the late morning-early evening for European observers and from around sunrise (or before) through late morning-early afternoon for skywatchers in the Americas. Because the planet is tiny and the Sun deadly bright, you’ll need a small telescope capped with a safe solar filter to watch the event. Remember, never look directly at the Sun at any time.

Nov. 15, 1999 transit of Mercury photographed in UV light by the TRACE satellite. Credit: NASA
Nov. 15, 1999 transit of Mercury photographed in UV light by the TRACE satellite. Credit: NASA

If you’re greeted with cloudy skies or live where the transit can’t be seen, be sure to check out astronomer Gianluca Masi’s live stream of the event. He’ll hook you up starting at 11:00 UT (6 a.m. CDT) tomorrow.

The table below includes the times across the major time zones in the continental U.S. for Monday May 9:

Time Zone Eastern (EDT) Central (CDT) Mountain (MDT) Pacific (PDT)
Transit start 7:12 a.m. 6:12 a.m. 5:12 a.m. Not visible
Mid-transit 10:57 a.m. 9:57 a.m. 8:57 a.m. 7:57 a.m.
Transit end 2:42 p.m. 1:42 p.m. 12:42 p.m. 11:42 a.m.

Watch Fast and Furious All-sky Aurora Filmed in Real Time

If seeing the Northern or Southern Lights hasn’t been crossed off your bucket list yet, this video is the next best thing to seeing the aurora live. Astrophotographer extraordinaire Thierry Legault has captured spectacular views of the Aurora Borealis from Norway, filmed in real time.

“I was in Norway in early November,” Thierry told Universe Today, “this was my 5th stay and really the best one, with incredible auroras. At moments they were so large and fast that we didn’t know where to look.” He added they were “totally hypnotic.”

The 16-minute video includes 6 of the best sequences Legault captured. “I included the start and finish of the sequences to show their behavior to people who have never witnessed them,” he said. “The auroras seem to be alive, sometimes like snakes or rivers.”

Legault used a Sony Alpha 7s, which he says is the only camera able to record video like this in such lighting. The video is recorded at 25 frames a second.

For the best view of the video, switch to full HD mode (1080p) and full screen.

Legault has been going to Norway annually to see the aurora. Here are the views he captured last year.

See more of Legault’s work at his website. He has technical pages there with advice for capturing the night sky. He provides more details and tips in his excellent book, Astrophotography.

Does the Red Planet Have Green Auroras?

Martian auroras will never best the visual splendor of those we see on Earth, but have no doubt. The Red Planet still has what it takes to throw an auroral bash. Witness the latest news from NASA’s MAVEN atmospheric probe

In December 2014, it detected widespread auroras across Mars’ northern hemisphere dubbed the “Christmas Lights”. If a similar display happened on Earth, northern lights would have been visible from as far south as Florida.

“It really is amazing,” says Nick Schneider who leads MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument team at the University of Colorado.  “Auroras on Mars appear to be more wide ranging than we ever imagined.”

A beautiful curtain of rays spread across the northern sky just last night (May 12) as seen from Duluth, Minn. Aurora colors on Earth are caused by the excitation of nitrogen and oxygen atoms from high-speed particles from the solar wind. Oxygen is responsible for most of the aurora's greens and reds. Credit: Bob King
A beautiful curtain of auroral rays spreads across the northern sky last night (May 12) as seen from Duluth, Minn. Aurora colors on Earth are caused by the excitation of nitrogen and oxygen atoms by high-speed particles in the solar wind. Oxygen in particular is responsible for most of the aurora’s greens and reds. Credit: Bob King

Study the map and you’ll see the purple arcs extend to south of 30° north latitude. So what would Martian auroras look like to the human eye? Would we see an arcade of nested arcs if we faced east or west from 30°N? Well, er, yes, if you could see into the ultraviolet end of the spectrum. Mars’ atmosphere is composed mostly of carbon dioxide, so most of the auroral emissions occur when high speed solar wind particles ionize CO2 molecules and carbon monoxide to produce UV light. Perhaps properly suited-up bees, which can see ultraviolet, would be abuzz at the sight.

High-speed particles from the Sun, mostly electrons, strike oxygen and nitrogen atoms in Earth's upper atmosphere. Credit: NASA
High-speed particles from the Sun, mostly electrons, strike oxygen and nitrogen atoms in Earth’s upper atmosphere. As they return to their “relaxed” state, they emit light in characteristic colors. Credit: NASA

That’s not the end of the story however. Martian air does contain 0.13% oxygen, the element that puts the green and red in Earth’s auroras. The “Christmas Lights” penetrated deeply into Mars’ atmosphere, reaching an altitude of just 62 miles (100 km) above its surface. Here, the air is relatively thicker and richer in oxygen than higher up, so maybe, just maybe Christmas came in green wrapping.

Mars has magnetized rocks in its crust that create localized, patchy magnetic fields (left). In the illustration at right, we see how those fields extend into space above the rocks. At their tops, auroras can form. Credit: NASA
Mars has magnetized rocks in its crust that create localized, patchy magnetic fields (left). In the illustration at right, we see how those fields extend into space above the rocks. At their “peaks”, auroras can form. Credit: NASA

Nick Schneider, who leads MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument team, isn’t certain but thinks it’s possible that a diffuse green glow could appear in Mars’ sky during particularly energetic solar storms.

A magnetosphere is that area of space, around a planet, that is controlled by the planet's magnetic field. The shape of the Earth's magnetosphere is the direct result of being blasted by solar wind, compressed on its sunward side and elongated on the night-side, the magnetotail. Credits: NASA
Earth’s  magnetosphere, an area of space that’s controlled by the planet’s magnetic field, guides solar wind electrons and protons along magnetic field lines into the atmosphere in the polar regions  to create auroras. The planet’s field is created by electric currents generated in its outer nickel-iron core.
Credits: NASA

While the solar wind produces auroras at both Earth and Mars, they originate in radically different ways. At Earth, we’re ensconced in a protective planet-wide magnetic field. Charged particles from the Sun are guided to the Earth’s poles by following a multi-lane freeway of  global magnetic field lines.  Mars has no such organized, planet-wide field. Instead, there are many locally magnetic regions. Particles arriving from the Sun go where the magnetism takes them.

“The particles seem to precipitate into the atmosphere anywhere they want,” says Schneider. “Magnetic fields in the solar wind drape across Mars, even into the atmosphere, and the charged particles just follow those field lines down into the atmosphere.”

Maybe one day, NASA or one of the other space agencies will send a lander with a camera that can shoot long time exposures at night. We’ll call it the “Go Green” initiative.