APOD: Aurora over Sweden (2016 May 03)

[APOD Robot]

Aurora over Sweden

Explanation: It was bright and green and stretched across the sky. This striking aurora display was captured last month just outside of �stersund, Sweden. Six photographic fields were merged to create the featured panorama spanning almost 180 degrees. Particularly striking aspects of this aurora include its sweeping arc-like shape and its stark definition. Lake Storsj�n is seen in the foreground, while several familiar constellations and the star Polaris are visible through the aurora, far in the background. Coincidently, the aurora appears to avoid the Moon visible on the lower left. The aurora appeared a day after a large hole opened in the Sun's corona allowing particularly energetic particles to flow out into the Solar System. The green color of the aurora is caused by oxygen atoms recombining with ambient electrons high in the Earth's atmosphere.

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[Ann]

An APOD from Sweden! Congrats, Göran Strand. You have posted many fine pictures here, and you deserve an APOD.

But I must quote Sappho here:

The sinking moon has left the sky,
The Pleiades have also gone.
Midnight comes--and goes, the hours fly
And solitary still, I lie.

Ann

[Asterhole]

It is not often an aurora borealis is seen in such a brilliant hue - and so sharply defined. It must not have lasted for very long, so the photographer had to have had a very small window of opportunity to capture this - in six frames. Nice work and good catch!

[Fred the Cat]

Speaking of electrons. First it was MeV, then a GeV, then a TeV. Now CERN announces its heavy ions are colliding at the astonishing energy of a PeV – a quadrillion electron volts.

I think we should start worrying. How much energy is really a PeV's-worth in a down-to-Earth measurement? “This energy is that of a bumblebee hitting us on the cheek on a summer day…" Of course it's concentrated "(a billion-billion-billion) times smaller" per the article but it does seem a bit inefficient considering that bees-worth of energy consumes 6% of CERN's budget in power consumption. That stings!

I wonder how much it would take to power today's aurora. A quadrillion fireflies?

[neufer]

I wonder how much it would take to power today's aurora. A quadrillion fireflies?

• I wonder how much it would take to power a quadrillion fireflies?

[b][color=#0000FF][size=150]Firefly larva feeding[/size][/color][/b]

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<<Lampyris noctiluca, the common glow-worm of Europe, is a firefly species of the genus Lampyris.

The predatory larvae feed for two or three years on slugs and snails which they inject with a brown toxic digestive fluid, delivered by a series of nips and bites. The poison takes a while to work, and the larva has to be careful not to become stuck to any protective mucus that its prey may secrete. The prey is gradually paralysed and the digestive fluid turns part of it into a brown broth that the larva can lap up. The prey remains alive, and some partially eaten victims have been known to crawl away after the meal.

The slugs and snails are often 200 times the weight of the beetle larva. The larvae are nocturnal, and are most active during moist conditions, when their prey are most active.>>

<<The slug (~32.174 lb_m) is a unit of mass that accelerates by 1 ft/s² when a force of one pound is exerted on it. The blob is the inch version of the slug (1 blob = 12 slugs). This unit is also called a slugette, and a snail. (Similar metric units include the "glug" in the cgs system, and the "mug" in the mks system.)>>

[llan]

I am from a place that doesn't have many auroras. I'd like to know if the picture is similar to what the human eye sees? Also how common are they? Thanks for putting up these wonderful pictures.
Bob

[Chris Peterson]

I am from a place that doesn't have many auroras. I'd like to know if the picture is similar to what the human eye sees? Also how common are they? Thanks for putting up these wonderful pictures.

The camera enhances both the intensity and the color. Visually, this would have been very apparent- easily several times brighter than the Milky Way, and bright enough to be distinctly green. Probably more like this:

AuroraSweden_Strand_1500_vis.jpg

[geckzilla]

It also would have appeared more or less straight, stretching from one horizon to the other overhead.

[llan]

Thanks a lot. Seeing one is on my list.
Bob

[Fred the Cat]

I wonder how much it would take to power today's aurora. A quadrillion fireflies?

<<The slug (~32.174 lb_m) is a unit of mass that accelerates by 1 ft/s² when a force of one pound is exerted on it. The blob is the inch version of the slug (1 blob = 12 slugs). This unit is also called a slugette, and a snail. (Similar metric units include the "glug" in the cgs system, and the "mug" in the mks system.)>>

I think you're on to something Art. Perhaps accelerators have always been too high speed. If we slowed down matter collisions to "slug" rates we may discover why plasma is such a unique state which may provide clues to matter's other mysteries. Blobs, slugs and snails may be the key to understanding the universe and CERN's power bill.

Now if we could only discover what that goo is gastropods leave behind.

[neufer]

Blobs, slugs and snails may be the key to understanding the universe and CERN's power bill.

• But... CERN was directly responsible for killing off the last snail male

<<The World Wide Web (WWW) was invented by English scientist Tim Berners-Lee in 1989. He wrote the first web browser in 1990 while employed at CERN in Switzerland.>>

[Fred the Cat]

• But... CERN was directly responsible for killing off the last snail male

Tim may be the reason we're all here and, inadvertently, made direct communication obsolete but you're wrong about the demise of the last snail male. There are a few of us around - still.

[neufer]

Nancy Ritz's friend from the wrong side of the tracks, Sluggo Smith

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• But... CERN was directly responsible for killing off the last snail male

Tim may be the reason we're all here and, inadvertently, made direct communication obsolete but you're wrong about the demise of the last snail male. There are a few of us around - still.