That New Kind of Aurora Called “Steve”? Turns Out, it Isn’t an Aurora at All

Since time immemorial, people living in the Arctic Circle or the southern tip of Chile have looked up at the night sky and been dazzled by the sight of the auroras. Known as the Aurora Borealis in the north and Aurora Australis in the south (the “Northern Lights” and “Southern Lights”, respectively) these dazzling displays are the result of interactions in the ionosphere between charged solar particles and the Earth’s magnetic field.

However, in recent decades, amateur photographers began capturing photos of what appeared to be a new type of aurora – known as STEVE. In 2016, it was brought to the attention of scientists, who began trying to explain what accounted for the strange ribbons of purple and white light in the night sky. According to a new study, STEVE is not an aurora at all, but an entirely new celestial phenomenon.

The study recently appeared in the Geophysical Research Letters under the title “On the Origin of STEVE: Particle Precipitation or Ionospheric Skyglow?“. The study was conducted by a team of researchers from the Department of Physics and Astronomy from the University of Calgary, which was led by Beatriz Gallardo-Lacourt (a postdoctoral associate), and included Yukitoshi Nishimura – an assistant researcher of the Department of Atmospheric and Oceanic Sciences at the University of California.

STEVE, as imaged by Dave Markel in the skies above northern Canada. Copyright: davemarkelphoto

STEVE first became known to scientists thanks to the efforts of the Alberta Aurora Chasers (AAC), who occasionally noticed these bright, thin streams of white and purple light running from east to west in the night sky when photographing the aurora. Unlike auroras, which are visible whenever viewing conditions are right, STEVE was only visible a few times a year and could only be seen at high latitudes.

Initially, the photographers thought the light ribbons were the result of excited protons, but these fall outside the range of wavelengths that normal cameras can see and require special equipment to image. The AAC eventually named the light ribbons “Steve” – a reference to the 2006 film Over the Hedge. By 2016, Steve was brought to the attention of scientists, who turned the name into a backronym for Strong Thermal Emission Velocity Enhancement.

For their study, the research team analyzed a STEVE event that took place on March 28th, 2008, to see if it was produced in a similar fashion to an aurora. To this end, they considered previous research that was conducted using satellites and ground-based observatories, which included the first study on STEVE (published in March of 2018) conducted by a team of NASA-led scientists (of which Gallardo-Lacourt was a co-author).

This study indicated the presence of a stream of fast-moving ions and super-hot electrons passing through the ionosphere where STEVE was observed. While the research team suspected the two were connected, they could not conclusively state that the ions and electrons were responsible for producing it. Building on this, Gallardo-Lacourt and her colleagues analyzed the STEVE event that took place in March of 2008.

Rays of aurora borealis reach 60 miles and higher over the Pacific Northwest on Jan. 20, 2016 in this photo taken by astronauts Scott Kelly and Tim Peake from the International Space Station. Credit: NASA

They began by using images from ground-based cameras that record auroras over North America, which they then combined with data from the National Oceanic and Atmospheric Administration‘s (NOAA) Polar Orbiting Environmental Satellite 17 (POES-17). This satellite, which can measure the precipitation of charged particles into the ionosphere, was passing directly over the ground-based cameras during the STEVE event.

What they found was that the POES-17 satellite detected no charged particles raining down on the ionosphere during the event. This means that STEVE is not likely to be caused by the same mechanism as an aurora, and is therefore an entirely new type of optical phenomenon – which the team refer to as “skyglow”. As Gallardo-Lacourt explained in an AGU press release:

“Our main conclusion is that STEVE is not an aurora. So right now, we know very little about it. And that’s the cool thing, because this has been known by photographers for decades. But for the scientists, it’s completely unknown.”

Looking ahead, Galladro-Lacourt and her colleagues seek to test the conclusions of the NASA-led study. In short, they want to find out whether the streams of fast ions and hot electrons that were detected in the ionosphere are responsible for STEVE, or if the light is being produced higher up in the atmosphere. One thing is for certain though; for aurora chasers, evening sky-watching has become more interesting!

Further Reading: AGU

How Can You see the Northern Lights?

The Northern Lights have fascinated human beings for millennia. In fact, their existence has informed the mythology of many cultures, including the Inuit, Northern Cree, and ancient Norse. They were also a source of intense fascination for the ancient Greeks and Romans, and were seen as a sign from God by medieval Europeans.

Thanks to the birth of modern astronomy, we now know what causes both the Aurora Borealis and its southern sibling – Aurora Australis. Nevertheless, they remain the subject of intense fascination, scientific research, and are a major tourist draw. For those who live north of 60° latitude, this fantastic light show is also a regular occurrence.

Causes:

Aurora Borealis (and Australis) is caused by interactions between energetic particles from the Sun and the Earth’s magnetic field. The invisible field lines of Earth’s magnetoshere travel from the Earth’s northern magnetic pole to its southern magnetic pole. When charged particles reach the magnetic field, they are deflected, creating a “bow shock” (so-named because of its apparent shape) around Earth.

However, Earth’s magnetic field is weaker at the poles, and some particles are therefore able to enter the Earth’s atmosphere and collide with gas particles in these regions. These collisions emit light that we perceive as wavy and dancing, and are generally a pale, yellowish-green in color.

The variations in color are due to the type of gas particles that are colliding. The common yellowish-green is produced by oxygen molecules located about 100 km (60 miles) above the Earth, whereas high-altitude oxygen – at heights of up to 320 km (200 miles) – produce all-red auroras. Meanwhile, interactions between charged particles and nitrogen will produces blue or purplish-red auroras.

Variability:

The visibility of the northern (and southern) lights depends on a lot of factors, much like any other type of meteorological activity. Though they are generally visible in the far northern and southern regions of the globe, there have been instances in the past where the lights were visible as close to the equator as Mexico.

In places like Alaska, Norther Canada, Norway and Siberia, the northern lights are often seen every night of the week in the winter. Though they occur year-round, they are only visible when it is rather dark out. Hence why they are more discernible during the months where the nights are longer.

The magnetic field and electric currents in and around Earth generate complex forces that have immeasurable impact on every day life. The field can be thought of as a huge bubble, protecting us from cosmic radiation and charged particles that bombard Earth in solar winds. It’s shaped by winds of particles blowing from the sun called the solar wind, the reason it’s flattened on the “sun-side” and swept out into a long tail on the opposite side of the Earth. Credit: ESA/ATG medialab
The magnetic field and electric currents in and around Earth generate complex forces, and also lead to the phenomena known as aurorae. Credit: ESA/ATG medialab

Because they depend on the solar wind, auroras are more plentiful during peak periods of activity in the Solar Cycle. This cycle takes places every 11 years, and is marked by the increase and decrease of sunspots on the sun’s surface. The greatest number of sunspots in any given solar cycle is designated as a “Solar Maximum“, whereas the lowest number is a “Solar Minimum.”

A Solar Maximum also accords with bright regions appearing in the Sun’s corona, which are rooted in the lower sunspots. Scientists track these active regions since they are often the origin of eruptions on the Sun, such as solar flares or coronal mass ejections.

The most recent solar minimum occurred in 2008. As of January 2010, the Sun’s surface began to increase in activity, which began with the release of a lower-intensity M-class flare. The Sun continued to get more active, culminating in a Solar Maximum by the summer of 2013.

Locations for Viewing:

The ideal places to view the Northern Lights are naturally located in geographical regions north of 60° latitude.  These include northern Canada, Greenland, Iceland, Scandinavia, Alaska, and Northern Russia. Many organizations maintain websites dedicated to tracking optimal viewing conditions.

The camera recorded pale purple and red but the primary color visible to the eye was green. Credit: Bob Kin
An image captured of the northern lights, which appear pale purple and red, though the primary color visible to the eye was green. Credit: Bob Kin

For instance, the Geophysical Institute of the University of Alaska Fairbanks maintains the Aurora Forecast. This site is regularly updated to let residents know when auroral activity is high, and how far south it will extend. Typically, residents who live in central or northern Alaska (from Fairbanks to Barrow) have a better chance than those living in the south (Anchorage to Juneau).

In Northern Canada, auroras are often spotted from the Yukon, the Northwest Territories, Nunavut, and Northern Quebec. However, they are sometimes seen from locations like Dawson Creek, BC; Fort McMurry, Alberta; northern Saskatchewan and the town of Moose Factory by James Bay, Ontario. For information, check out Canadian Geographic Magazine’s “Northern Lights Across Canada“.

The National Oceanic and Atmospheric Agency also provides 30 minute forecasts on auroras through their Space Weather Prediction Center. And then there’s Aurora Alert, an Android App that allows you to get regular updates on when and where an aurora will be visible in your region.

Understanding the scientific cause of auroras has not made them any less awe-inspiring or wondrous. Every year, countless people venture to locations where they can be seen. And for those serving aboard the ISS, they got the best seat in the house!

Speaking of which, be sure to check out this stunning NASA video which shows the Northern Lights being viewed from the ISS:

We have written many interesting articles about Auroras here at Universe Today. Here’s The Northern and Southern Lights – What is an Aurora?, What is the Aurora Borealis?, What is the Aurora Australis?, What Causes the Northern Lights?, How Does the Aurora Borealis Form?, and Watch Fast and Furious All-sky Aurora Filmed in Real Time.

For more information, visit the THEMIS website – a NASA mission that is currently studying space weather in great detail. The Space Weather Center has information on the solar wind and how it causes aurorae.

Astronomy Cast also has episodes on the subject, like Episode 42: Magnetism Everywhere.

Sources:

Stunning Auroras From the Space Station in Ultra HD – Videos

Still image shows a stunning aurora captured from the International Space Station. This frame is from a compilation of ultra-high definition time-lapses of the aurora shot from the space station.  Credit: NASA
Still image shows a stunning aurora captured from the International Space Station. This frame is from a compilation of ultra-high definition time-lapses of the aurora shot from the space station. Credit: NASA

Stunning high definition views of Earth’s auroras and dancing lights as seen from space like never before have just been released by NASA in the form of ultra-high definition videos (4K) captured from the International Space Station (ISS).

Whether seen from the Earth or space, auroras are endlessly fascinating and appreciated by everyone young and old and from all walks of life.

The spectacular video compilation, shown below, was created from time-lapses shot from ultra-high definition cameras mounted at several locations on the ISS.

It includes HD view of both the Aurora Borealis and Aurora Australis phenomena seen over the northern and southern hemispheres.

The video begins with an incredible time lapse sequence of an astronaut cranking open the covers off the domed cupola – everyone’s favorite locale. Along the way it also shows views taken from inside the cupola.

The cupola also houses the robotics works station for capturing visiting vehicles like the recently arrived unmanned SpaceX Dragon and Orbital ATK Cygnus cargo freighters carrying science experiments and crew supplies.

The video was produced by Harmonic exclusively for NASA TV UHD;

Video caption: Ultra-high definition (4K) time-lapses of both the Aurora Borealis and Aurora Australis phenomena shot from the International Space Station (ISS). Credit: NASA

The video segue ways into multi hued auroral views including Russian Soyuz and Progress capsules, the stations spinning solar panels, truss and robotic arm, flying over Europe, North America, Africa, the Middle East, star fields, the setting sun and moon, and much more.

Auroral phenomena occur when electrically charged electrons and protons in the Earth’s magnetic field collide with neutral atoms in the upper atmosphere.

“The dancing lights of the aurora provide a spectacular show for those on the ground, but also capture the imaginations of scientists who study the aurora and the complex processes that create them,” as described by NASA.

Here’s another musical version to enjoy:

The ISS orbits some 250 miles (400 kilometers) overhead with a multinational crew of six astronauts and cosmonauts living and working aboard.

The current Expedition 47 crew is comprised of Jeff Williams and Tim Kopra of NASA, Tim Peake of ESA (European Space Agency) and cosmonauts Yuri Malenchenko, Alexey Ovchinin and Oleg Skripochka of Roscosmos.

Some of the imagery was shot by recent prior space station crew members.

Here is a recent aurora image taken by flight engineer Tim Peake of ESA as the ISS passed through on Feb. 23, 2016.

“The @Space_Station just passed straight through a thick green fog of #aurora…eerie but very beautiful,” Peake wrote on social media.

The @Space_Station just passed straight through a thick green fog of #aurora…eerie but very beautiful.  Credit: NASA/ESA/Tim Peake
The @Space_Station just passed straight through a thick green fog of #aurora…eerie but very beautiful. Credit: NASA/ESA/Tim Peake

A new room was just added to the ISS last weekend when the BEAM experimental expandable habitat was attached to a port on the Tranquility module using the robotic arm.

BEAM was carried to the ISS inside the unpressurized trunk section of the recently arrived SpaceX Dragon cargo ship.

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

Ken Kremer

Venus Compared to Earth

Venus is often referred to as “Earth’s Twin” (or “sister planet”), and for good reason. Despite some rather glaring differences, not the least of which is their vastly different atmospheres, there are enough similarities between Earth and Venus that many scientists consider the two to be closely related. In short, they are believed to have been very similar early in their existence, but then evolved in different directions.

Earth and Venus are both terrestrial planets that are located within the Sun’s Habitable Zone (aka. “Goldilocks Zone”) and have similar sizes and compositions. Beyond that, however, they have little in common. Let’s go over all their characteristics, one by one, so we can in what ways they are  different and what ways they are similar.

Continue reading “Venus Compared to Earth”

Incredible Aurora Outburst From Recent X-Class Flare

Our Twitter feeds just exploded with pictures of an auroral outburst in the UK, Scandinavia, Iceland and even from the International Space Station! Thanks to the X4.9 class solar flare on on Feb. 25, the resulting CME hit Earth’s magnetic field today and triggered geomagnetic storms. Take a look at some of the images pouring in, featuring dancing curtains of reds, greens, purples and pinks:

'This is how a CME impact looks like," tweeted Göran Strand from Östersund, Sweden. "Lot's of aurora tonight."
‘This is how a CME impact looks like,” tweeted Göran Strand from Östersund, Sweden. “Lot’s of aurora tonight.”
The aurora seen over Scotland on Feb. 27, 2014. Credit and copyright: Euan McIntosh.
The aurora seen over Scotland on Feb. 27, 2014. Credit and copyright: Euan McIntosh.

Red curtains of aurora.  'I'm amazed, blown away, never seen aurora before EVER,' said astrophotographer Wendy Clark.   'Just incredible, stood for ages watching it develop.'
Red curtains of aurora. ‘I’m amazed, blown away, never seen aurora before EVER,’ said astrophotographer Wendy Clark. ‘Just incredible, stood for ages watching it develop.’
This view of the aurora from Chobham, Surrey  in the UK on Feb. 27, 2014. Credit and copyright: Tom Chitson.
This view of the aurora from Chobham, Surrey in the UK on Feb. 27, 2014. Credit and copyright: Tom Chitson.

This timelapse shows the aurora display over Swordale, Isle of Lewis, Scotland on Feb. 27, 2014:

Here are a few notable tweets:

Here are more images that came in overnight:

An aurora rising from the east above the Science Operations Center at Poker Flat. Aurora seen in Alaska on Feb. 28, 2014. The bubble in the lower right is a dome housing a scientific camera which happens to be in just the right spot to appear as if it's blowing the aurora out. Credit and copyright: Jason Arhns.
An aurora rising from the east above the Science Operations Center at Poker Flat. Aurora seen in Alaska on Feb. 28, 2014. The bubble in the lower right is a dome housing a scientific camera which happens to be in just the right spot to appear as if it’s blowing the aurora out. Credit and copyright: Jason Arhns.
Northern lights from Carmyllie, Angus, Scotland on Feb. 27/28, 2014. Credit and copyright: Mick Walton.
Northern lights from Carmyllie, Angus, Scotland on Feb. 27/28, 2014. Credit and copyright: Mick Walton.
  Aurora reflects on water, as seen  on February 20, 2014 near Bremnes, Troms Fylke, Norway. Credit and copyright: Ronny Årbekk.
Aurora reflects on water, as seen on February 20, 2014 near Bremnes, Troms Fylke, Norway. Credit and copyright: Ronny Årbekk.

To see more images, take a look at the Twitter feed of @VirtualAstro, or see the aurora gallery at SpaceWeather.com.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Once in a Lifetime Image: Emperor Penguins Under the Aurora Australis

Emperor Penguins on the Antarctic Sea Ice Under the Aurora Australis. Credit and copyright: Stefan Christmann. Used by permission.

Photographer Stefan Christmann called this incredible Antarctic view a once in a lifetime experience.

“It was the most impressive experience to sit on the sea-ice and watch the Aurora Australis dance above the penguin colony with the sounds of the chicks and the adult penguins. I feel truly blessed for having had the opportunity to witness this once in a lifetime experience,” he told Universe Today.

Christmann is currently based in Antarctica, working at the German Antarctic research station Neumayer III. He is an “overwinterer” — scientific and technical staff who stay at the base for the entire southern winter — and will stay in Antarctica for an uninterrupted 14 months. “As a physicist, my duty is to maintain the data acquisition of our seismological and geomagnetic observatories as well as the analysis of the collected data,” Christmann said.

But he is also an accomplished photographer. His website and Facebook page are filled with beautiful nature images from around the world, and recently feature the Emperor penguins and their adorable chicks, as well as the stark beauty of the Antarctic landscape.

Originally from Germany, he studied photography in the US, and his work has now brought him to an extended stay in Antarctica.

Christmann explained the conditions and the difficulties in obtaining this shot, one he had long hoped for, the planning of it always in the back of his mind.

“The picture was taken at Atka-Bay on the sea-ice. The bay is roughly 8 km away from our station so the penguin colony is a popular destination for free-time trips. The idea of a photo of the Aurora Australis above the penguin colony had been in my head for a long time, but the conditions have to be just right –which usually never happens. You need a full Moon, high magnetic activity and a cloudless sky. Also the penguins should be standing close enough to the ice-berg. I made multiple attempts to get the photo, but we either had incoming clouds, low activity or had to cancel our stay because of wind picking up (which can be really dangerous out on the sea-ice).”

And time was short, as after he had been outside for a few hours the wind picked up and he and his accomplices had to leave the ice for safety reasons. “Otherwise we probably would have sat there all night!” Christmann said. The image was taken on October 1, 2012.

Christmann shared what equipment he uses as well as a few tips for Antarctic and cold weather photography.

“I used a Nikon D700 Fullframe DSLR with an AF-S G-Nikkor 14-24mm f/2.8. ISO settings varied with the intensity of the aurora from ISO 500-800,” he said. “F-Stops in the range of 4.0-5.6 and Exposure times from 20s to 30s. I try to keep ISO as low as possible for noise reasons and also try to limit the exposure time in order not to get star trails. It’s either super long star trails or almost star-dots, but I don’t really like the in between. A full battery charge (in my case around 2500mAh) lasts around 1h in the cold, so I had to switch batteries twice during our stay out on the ice!”

Asked what other details he felt was important to share about this image, Christmann said, “Antarctica is an incredible place where nature dwarfs anything made by humans. Hopefully people will gain even more interest in this continent and help to protect it as well as its inhabitants.”

To see more of Christmann’s work visit his website, Nature in Focus or his Facebook page, where he shares many pictures of his Antarctic adventure.

Please note: This image may not be re-posted, used or copied without the express permission of Stefan Christmann.

Shimmering Aurora Australis Timelapse

Our friends in the Southern Hemisphere have been enjoying some lovely auroral displays following the Sun’s recent activity. Here’s a new timelapse video of the night sky view on July 17, 2012, compiled by Maki Yanagimachi at Mt. John University Observatory in New Zealand. Enjoy the multi-colored aurora shimmering across the sky.

Aurora Alert for September 26 and 27!

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Skywatchers in northern Europe are already seeing some aurora activity as a strong-to-severe geomagnetic storm is in progress, according to the NOAA Space Weather Prediction Center and SpaceWeather.com. The fuel for this storm was a coronal mass ejection over the weekend that has now reached Earth. This is great news for skywatchers, as both the Northern and Southern lights should be spectacular. But this is not so good news for satellite companies. The Goddard Space Weather Lab reports a “strong compression of Earth’s magnetosphere. Simulations indicate that solar wind plasma [has penetrated] close to geosynchronous orbit starting at 13:00 UT.” Geosynchronous satellites could therefore be directly exposed to solar wind plasma and magnetic fields.

Predicted auroral oval over the South Pole, for Sept. 27, 2011. Credit: NOAA Space Weather Prediction Center.

The active region on the Sun will be pointed straight at Earth in few days as the Sun rotates, so this could be a week of high auroral activity. If you are able to capture images, send the to Universe Today via email or upload them to our Flickr page, and we’ll share them! See an image below of the Sun from September 25, 2011, showing the Active Region 1302, courtesy of John Chumack.


For more information and updates see the links above, or the Geophysical Institute at the University of Alaska Fairbanks.

The Full Solar Disk in Hydrogen Alpha Light 09-25-2011. Credit: John Chumack. Click for larger version on Flickr.

Awesome Aurora Photographed by Shuttle/ISS Crews

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The STS-135 crew of space shuttle Atlantis and the Expedition 28 crew of the International Space Station were treated with great views of the Aurora Australis. Here’s one shot the crews photographed, showing a panoramic view of the station/shuttle complex along with several different astronomical beauties! The aurora shows up brightly, but what else is in the image? Looking closely –and southern hemisphere observers might recognize some objects better — but do you see the globular cluster Omega Centauri, the Coalsack Nebula and the Southern Cross? Anyone see anything else?

See below for another great aurora shot from the ISS, where the green glow shows up even better:

The Southern Lights or Aurora Australis as seen from the space station and space shuttle. Credit: NASA

These images were taken on Thursday during one of the “night” passes for the station/shuttle. The astronauts mentioned the aurora during media interviews on Friday. “We saw an incredible Southern Lights aurora,” said STS-135 pilot Doug Hurley. “It was the best one I’ve seen in my two spaceflights. It was just unbelievable, the view out the cupola.”

See larger views on NASA’s mission gallery page.