Space Tornadoes

[Ford Prefect]

No, really.

Vienna, Austria -- Earth-bound tornadoes are puny compared to "space tornadoes," which span a volume as large as Earth and produce electrical currents exceeding 100,000 amperes, according to new observations by a suite of five NASA space probes.

The probe cluster, called Time History of Events and Macroscale Interactions during Substorms (THEMIS), recorded the extent and power of these electrical funnels as the probes passed through them during their orbit of Earth. Ground measurements showed that the space tornadoes channel the electrical current into the ionosphere to spark bright and colorful auroras on Earth.


The findings were presented during a press conference at 10 a.m. CEST (1 a.m. PDT) today (Thursday, April 23) at the general assembly of the European Geosciences Union (EGU) in Vienna, Austria.

Space tornadoes are rotating plasmas of hot, ionized gas flowing at speeds of more than a million miles per hour, far faster than the 200 m.p.h. winds of terrestrial tornadoes, according to Andreas Keiling, a research space physicist at the University of California, Berkeley's Space Sciences Laboratory.

Keiling works on THEMIS, which was built and is now operated by UC Berkeley. The five space probes were launched by NASA in February 2007 to solve a decades-long mystery about the origin of magnetic storms that power the Northern and Southern Lights

Both terrestrial and space tornadoes consist of funnel-shaped structures. Space tornadoes, however, generate huge amounts of electrical currents inside the funnel. These currents flow along twisted magnetic field lines from space into the ionosphere where they power several processes, most notably bright auroras such as the Northern Lights, Keiling said.

While these intense currents do not cause any direct harm to humans, on the ground they can damage man-made structures, such as power transformers.

The THEMIS spacecraft observed these tornadoes, or "flow vortices," at a distance of about 40,000 miles from Earth. Simultaneous measurements by THEMIS ground observatories confirmed the tornadoes' connection to the ionosphere.

Keiling's colleagues include Karl-Heinz Glassmeier of the Institute for Geophysics and Extraterrestrial Physics (IGEP, TU) in Braunschweig, Germany, and Olaf Amm of the Finnish Meteorological Institute.

And I thought curved laser beams were cool.

[Patrick Degan]

There is just no end to the fascinating things discovered in space.

[Dark Flame]

That's....weird..but cool!

I'm wondering what makes them rotate, though. On Earth, the Coriolis Effect is a part of the rotation that leads to tornadoes, correct? But how does that work in space?

[Ford Prefect]

The article mentions 'twisted magnetic field lines', but it's not clear whether this is the source of the funnel formation (though I suspect it is).

[Jeremy]

Weak areas called "Polar Cusps" in the Earth's Magnetosphere. These areas allow plasma (solar wind?) to be siphoned from the Sun by Flux Ropes.

So sayeth a few minutes at Wikipedia looking up: Magnetosphere, Plasmasphere, Plasma scaling, and Birkeland current.

Is it basically one of those glass balls that have glowing tendrils connecting the interior glass surface to a metal coil at the origin?

[Junghalli]

That's a pretty fast rotation. Would it be at all dangerous to be caught in one of these things, or is the plasma way too thin for that?

[Jeremy]

I wonder if we could place some kind of wire coil in there to generate electricity.

[starslayer]

That's a pretty fast rotation. Would it be at all dangerous to be caught in one of these things, or is the plasma way too thin for that?

The plasma is much too thin. There would be a somewhat heavy radiation flux, but as long as you were just passing through, you would suffer no ill effects. Note that this requires you to actually be in the "walls" of the tornado. In the middle, it is for the most part quiescent, though still a much worse radiation environment than Earth's surface. In fact, it would be the same kind of radiation hazard faced by potential travellers to Mars or anywhere in the Solar System, including the Moon.

I wonder if we could place some kind of wire coil in there to generate electricity.

No. The B field strength is many orders of magnitude too small to generate any meaningful current in any conceivable wire coil. Hell, your average wall current probably would beat the pants off what could be generated using these. Besides, any coil of wire that could be used to do this would be so large as to be impossible to construct using current technology, even in space.

Is it basically one of those glass balls that have glowing tendrils connecting the interior glass surface to a metal coil at the origin?

Not really. What's basically happening here is that ions and charged particles are streaming towards Earth from the Sun as the solar wind. These particles, since they are moving charges, are affected by the Earth's magnetic field. They feel Lorentz forces and thus begin to spiral in towards the Earth's poles, creating the so-called "space tornadoes." When enough of these particles hit the atmosphere at once (still following the magnetic field), they generate an aurora. That light comes from gases in the atmosphere being excited by collisions with the incoming particles and thus giving off photons.

The plasma ball is somewhat different, except for the last step. It is basically a spherical capacitor. The power source charges the inner globe through some means, which induces an opposite charge on the inner surface of the outer globe. When the electric field between the two becomes strong enough, electrons feel enough force to be pulled through the gas inside and onto the other globe (which depends on whether the inside globe is positively or negatively charged). This ionizes and heats the gas, causing it to glow. Once the breakdown has occurred in a certain spot, it tends to continue to happen there, because the gas has already been ionized, so current flows much more easily. This effect manifests itself as the glowing strands connecting the globes. The strands move around because of convection in the gas caused by the heat from the current flow. When you touch the globe, the strands concentrate there because you become a ground to the system; in effect, you give an avenue for the charge on the outer globe to dissipate, so most of the current tends to flow to you. The colors are the result of the specific gas mixture the globe is filled with; different gases have different atomic energy levels, and thus produce different energy photons when excited.

[Fingolfin_Noldor]

If one really wants to find a really powerful tornado, I hear that magnetars; neutron stars with a huge magnetic field, have a layer of plasma that spins as the neutron star spins. The result is a highly supercharged dynamo, which periodically emits gamma ray pulses which can fry a nearby planet. Along with this spin is no doubt lots of vortices, because all chaotic spins tend to have them.