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APOD: Aurora over Sweden (2016 May 03)
Posted: Tue May 03, 2016 4:09 am
by 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.
[/b]
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Tue May 03, 2016 4:11 am
by 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
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Tue May 03, 2016 2:29 pm
by 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!
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Tue May 03, 2016 3:06 pm
by 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?
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Tue May 03, 2016 9:12 pm
by neufer
Fred the Cat wrote:
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?
https://en.wikipedia.org/wiki/Lampyris_noctiluca wrote:
<<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.>>
https://en.wikipedia.org/wiki/Slug_%28mass%29 wrote:
<<The slug (~32.174 lb
m) is a unit of mass that accelerates by 1 ft/s
2 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.)>>
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Tue May 03, 2016 9:35 pm
by 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
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Tue May 03, 2016 10:36 pm
by Chris Peterson
llan wrote: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:
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Wed May 04, 2016 12:11 am
by geckzilla
It also would have appeared more or less straight, stretching from one horizon to the other overhead.
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Wed May 04, 2016 8:17 am
by llan
Thanks a lot. Seeing one is on my list.
Bob
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Wed May 04, 2016 2:26 pm
by Fred the Cat
neufer wrote:Fred the Cat wrote:
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/s
2 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.
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Wed May 04, 2016 2:47 pm
by neufer
Fred the Cat wrote:
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
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Wed May 04, 2016 4:17 pm
by Fred the Cat
neufer wrote:
- 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.
Re: APOD: Aurora over Sweden (2016 May 03)
Posted: Wed May 04, 2016 5:03 pm
by neufer
Fred the Cat wrote:neufer wrote:
- 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.
