By Guest Work 25/04/2017 3


By Nathan Case, Lancaster University

A collaboration between aurora-hunting citizen scientists and a team of professional researchers has resulted in the discovery of a completely new type of aurora. The finding was made possible thanks to photos taken by aurora enthusiasts from across the globe which scientists could then compare with data from satellites. The Conversation

The aurora, more commonly known as the northern or southern lights, form when electrically charged particles collide with the gases in our upper atmosphere. These charged particles, which have been accelerated into our atmosphere by the Earth’s magnetic field, transfer their energy to the atmospheric gases (such as nitrogen and oxygen). This extra energy is then released in the form of light which gives us the majestic aurora.

The aurora varies in strength depending on how active the sun is. Normally, an aurora is only visible near the magnetic poles but, when particularly active, it can be seen from much further away.

 

We generally see the aurora as a band about the poles (known as the auroral oval). This band is often green, with tinges of red or purple thrown into the mix. But sightings of this new phenomenon were different – straight away people noticed it didn’t look like the “normal” aurora.

When pictures first starting appearing on social media, the odd aurora was widely assumed to be what is known as a “proton arc”, but scientists knew that this wasn’t right. Proton arcs are caused by protons (positively charged particles which make up the atomic nucleus along with neutrons) colliding with neutral gases in the atmosphere. Proton aurora are not visible by eye and are broad and diffuse. This new type of aurora, however, was visible by eye and was a bright, structured band of purple in the night sky. They knew it had to be something else – but what?

Meet Steve, the bright purple band reflected in the lake. Dave Markel Photography, ESA.

 

The Aurorasaurus citizen science project issued a call to arms to collect sightings of this as-yet-unnamed aurora. Over 50 sightings from countries including Canada, US, UK and New Zealand were reported during 2016 and 2017. Because this type of aurora didn’t yet have a name, the citizen scientists called it “Steve” (after the animated children’s film, Over the Hedge).

The biggest breakthrough in identifying “Steve” came when Eric Donovan, an associate professor of physics and astronomy at the University of Calgary in Canada, found an instance where a photo was taken of “Steve” at the same time as one of the European Space Agency’s Swarm satellites passed above it. Donovan found that as the satellite flew straight though Steve, data from the electric field instrument showed very clear changes.


Steve appears as a purple band (left of video). ‘Normal’ aurora appears as green (right of video).

 

Speaking at a recent scientific conference, Donovan said that “the temperature 300km above Earth’s surface jumped by 3000°C and the data revealed a 25km-wide ribbon of gas flowing westwards at about 6km per second compared to a speed of about ten metres per second either side of the ribbon.”

This result definitively proved that “Steve” is in fact a distinct feature from the normal aurora oval, as the ribbon was located south of the main aurora. It also showed that “Steve” is not a proton arc.

While we have now been able to measure “Steve”, we still aren’t sure what causes it. It seems that “Steve” is fairly common but it took the power of citizen science for it to really be noticed. Donovan says that research is still ongoing but that he thinks he is close to finding the cause.

Discoveries of new types of aurora are rare and this one highlights the importance of citizen scientists. If it weren’t for the dedication of amateur aurora hunters, we may never have started studying this new phenomenon. So if you think you’ve spotted “Steve”, make sure you submit your sighting to Aurorasaurus to help us learn more about this beautiful purple streak.

Nathan Case, Senior Research Associate in Space and Planetary Physics, Lancaster University

This article was originally published on The Conversation. Read the original article.


3 Responses to “Citizen scientists discover new type of aurora”

  • They are also known as field-aligned currents, magnetic ropes and magnetic cables. Originally Birkeland currents referred to electric currents that contribute to the aurora, caused by the interaction of the plasma in the Solar Wind with the Earth’s magnetosphere.
    “A Birkeland current is a set of currents that flow along geomagnetic field lines connecting the Earth’s magnetosphere to the Earth’s high latitude ionosphere. In the Earth’s magnetosphere, the currents are driven by the solar wind and interplanetary magnetic field and by bulk motions of plasma through the magnetosphere ” Wiki
    Auroral-like Birkeland currents created by scientist Kristian Birkeland in his terrella, featuring a magnetised anode globe in an evacuated chamber.
    https://en.wikipedia.org/wiki/Birkeland_current#/media/File:Birkeland-anode-globe-fig259.jpg

    • Interesting stuff, you have to be careful talking about electricity in space and even here on Earth as the establishment that is physics prefers not to study real phenomenon and will ignore it, instead relying upon speculation and mathematics to determine how the universe works.
      If your looking at electrical effects here on earth, you should also look further to the sun, to determine what drives geomagnetic storms and also a lot of our warming and cooling patterns. The electrical generation of our weather can be traced to sunspots, which are magnetic with positive and negative aspects. They lead to charged plasma ropes called coronal loops, that connect between a positive and negative sunspot. These loops can then explode if there is enough charge in them. This is a coronal mass ejection and causes particles to hurtle towards us (if the solar coronal loop is pointing at us), these particles interact with our magnetosphere and create phenomena like the aurora. It is an electrical effect from the sun which produces electrical effects here on earth.
      If you get the chance read “Weathermans guide to the sun” by Ben Davidson, not in libraries (just like books on the great physicist Nikola Tesla) but you will find on the net and is not expensive.
      If your keen on more books that do not subscribe to speculation but observations try Halton Arps “Quasars, Red shift and controversy”, there is one copy in New Zealand’s library database, be warned though he was black listed for his observations and forbidden to use the telescopes in the US because his observations do not agree with the mathematical blackboard universe theory.

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