Sprites

[Chris Peterson]

I caught three sets of sprites above a distant thunderstorm on September 2. I've been operating video allsky cameras for over ten years, and haven't caught any sprites before- probably because the meteor detection algorithm catches lightning and misses the much higher sprites. The fact that I got these makes me think there were hundreds more that got missed that night.

[neufer]

I caught three sets of sprites above a distant thunderstorm on September 2. I've been operating video allsky cameras for over ten years, and haven't caught any sprites before- probably because the meteor detection algorithm catches lightning and misses the much higher sprites. The fact that I got these makes me think there were hundreds more that got missed that night.

So, how did you catch these? (I.e., what were you doing different?)

[Chris Peterson]

So, how did you catch these? (I.e., what were you doing different?)

Nothing at all. The way the system works is that there is a motion detection algorithm that identifies a region of interest, and then only that small region is captured (normally, where there is a meteor). Lighting tends to trigger the system, but sprites are outside the captured region. The rest of the sky gets filled in from a single allsky frame captured after the event- by which time, any sprites associated with the lightning are gone. So what most likely happened here is that there were two or more lightning strokes in close succession. The first started the motion capture system, and a slightly later one triggered sprites that were still present when the allsky frame was recorded after the event. So what was different was that I was looking towards an extremely active storm system while I had completely clear skies between my camera and that system. Looking at the radar map for the time, I was actually looking through two separate storm cells, which might also have been the reason for multiple, closely spaced lighting strokes.

spritemap.jpg (25.48 KiB) Viewed 37213 times

[geckzilla]

Too bad they're only a few pixels. So how did you determine they are sprites and not blue jets? The distance above the clouds? Well, I assumed that but I have to ask anyway.

[Chris Peterson]

Too bad they're only a few pixels. So how did you determine they are sprites and not blue jets? The distance above the clouds? Well, I assumed that but I have to ask anyway.

Yes, the heights are about right. Mainly, however, I checked with a colleague who knows a lot about sprites, and records them himself on special cameras and radio equipment, and he was quite certain that these were sprites.

[neufer]

Could Electrical Sprites Hold the Key to Extraterrestrial Life?
by Amy Shira Teitel on November 22, 2011

<<In 1989, meteorologists discovered sprites. Not the spirits, elves, or pixies that pepper Shakespearean comedies but their equally elusive electrical namesakes. Lightning sprites are large scale electrical discharges inside the clouds above storms that make the upper atmosphere glow, sort of like a fluorescent lightbulb.

Meteorologists have already determined that sprites likely aren’t unique to Earth. In fact, this elusive form of lightning might be common throughout the solar system. Now, researchers at Tel Aviv University are asking whether the presence of sprites on other planets could indicate the presence of organic material in their atmospheres.

Though not an uncommon phenomena, sprites are incredibly hard to find and observe. They can only be captured with highly sensitive high speed cameras. Sprites occur in the Earth’s Mesosphere, layer between the stratosphere and the thermosphere – about 50 km to 90 km high. At this altitude, the gases that make up our atmosphere are much thinner and unable to hold heat from the Sun making the average temperature a chilly 5°F (-15°C) to as low as -184°F (-120°C).

But gases at this altitude are still thick enough to slow meteors – this is where they burn up and create what we see as meteor showers. Gases in the mesosphere are also thick enough to light up with sprites, providing a window into the composition of our atmosphere. Sprites, which glow reddish-orange, indicate the kinds of molecules present in this layer of the atmosphere.

Lightning isn’t a rare occurrence in our solar system, which leads researchers to suspect sprites might be found on Jupiter, Saturn, and Venus – all planets with the right environment for strong electrical storms. Just like on Earth, sprites found on these planets could open a window in their atmospheric composition, conductivity, and possibly point to the presence of exotic compounds.

Jupiter and Saturn present the most exciting environments. Both gas giants experience lightening storms with flashes more than 1,000 as powerful as those found on Earth. It’s on these planets that Ph.D. student Daria Dubrovin, with her supervisors Prof. Colin Price of Tel Aviv University’s Department of Geophysics and Planetary Sciences and Prof. Yoav Yair at the Open University of Israel, is focussing on.

Dubrovin has re-created these planetary atmospheres in a lab to study the presence of sprites in space. Or, as she describes her work, “We make sprites in a bottle.” She hopes this will provide a new understanding of electrical and chemical processes on other planets.

What’s more, understanding lightning on other worlds could help researchers understand the possibility of life on other worlds. As Dubrovin points out, lightning is commonly accepted as the generator of organic molecules that turned early Earth’s ocean into the life-filled primordial soup. Increased study of lightning on other planets could give another clue into the presence of extraterrestrial life. Their research could easily be applied to exoplanets, not just bodies in our solar system.

A lightning storm on Saturn has Dubrovin pretty excited. It’s currently producing over 100 electrical flashes per second, a rare occurrence even within the planet’s volatile cloud layers. If researchers could successfully gather images of higher altitude sprites from the Cassini spacecraft (currently in orbit around Saturn), it would not only yield information on the storm below but also add to the general knowledge base of sprites and lightning on other planets.>>

[neufer]

Breathe deeply, life’s a gas
Posted on November 30, 2011 by astrobob

[b][color=#0000FF]The moon photographed on July 31, 2011 out the window of the space station. Seen near setting, the moon appears to hover at edge of outer space: NASA[/color][/b]

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[b][color=#0000FF]The troposphere is characterized by clouds and weather; the mesosphere by the aurora borealis. Satellites and the space station orbit at the extreme edge called the exosphere. NASA with additions[/color][/b]

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<<By convention, outer space starts at 100 km or 62.1 miles above the Earth’s surface, but to get there, a plane or ship must first pass through five layers of atmosphere. The photo above, recently released by NASA, was taken from about 230 miles up by an astronaut on the International Space Station. Besides being beautiful to look at, it clearly shows several layers of our planet’s atmosphere. The lowest region, which contains 80 % of the atmosphere’s mass and 99% of its water vapor, is called the troposphere after the Greek tropos meaning ‘turning’ or ‘mixing’.

Mixing is the word in the lower atmosphere thanks to high and low pressure regions, winds and turbulence. Home to clouds, aerosols and weather, the troposphere is by far Earth’s most colorful air layer. Check out twilight’s orange glow in the astronaut pic.

Up above about 10 miles we enter the stratosphere, a calm region of thin, cold, clear air. If you take a cross-country plane trip, you’ll be cruising through its lower reaches. Unlike the troposphere, temperature increases as you ascend the approximately 30 miles from the bottom to the top due to the absorption of UV light from the sun by the ozone layer. This crucial region was created by life through photosynthesis and in turn protects life by absorbing much of the dangerous, short-wave UV radiation.

To get beyond the stratosphere into the gaspingly-thin air of the mesosphere, you’ll need to be an astronaut. Despite its tenuousness, the mesosphere’s one of the most action-packed places around, hosting everything from flaming meteors to the aurora borealis to fondue parties. Just wanted to see if you were paying attention. Things get chilly again as we ascend this layer. The bottom can be as toasty as the low 20s while the top dips to around 200 below, making it the coldest region of the atmosphere.

Higher up, the air continues to thin out but the temperature rises once again through the thermosphere reaching over 4,500 degrees F during the daytime. Since heat is a measure of the motion of atoms or molecules, the few remaining oxygen atoms at these altitudes dart about rapidly as they absorb energetic radiation from the sun. Yet the air is so rarefied, we’d never feel the heat; there are just too few atoms to bounce off of us to create a sensation of warmth. The sun’s energy also electrifies atoms at these heights making them capable of reflecting radio waves beamed from the Earth long distances from one station to another.

Once we’ve climbed the 250 miles into the exosphere, Earth falls away as we penetrate deeper into outer space. While 250 miles sounds like a lot of air, and illustrations make the atmosphere appear like a deep pool, the reality is much more stark. If our planet were shrunk to the size of an onion, the Earth’s atmosphere would only be as thick as the onion’s outermost skin.>>

[neufer]

[b][color=#FF0000]Red sprites captured by astronauts aboard the space station on April 30, 2012 while they passed over Myanmar (Burma) and just north of Malaysia. The white glow is lighting inside a thundercloud. Credit: NASA[/color][/b]

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Sprites and elves haunt nighttime thunderclouds
Posted on July 11, 2012 by astrobob

<<Ever since I learned about sprites, the bizarre electric discharges associated with thunderstorms that shoot up in the sky instead of down to the ground, I’ve wanted to see one. July’s a great month to be on the look out for these short-lived red flashes that come and go in milliseconds. They occur some 50 miles above active thunderstorms – about the same level as noctilucent clouds – and extend upward from 12 to 19 miles. The name refers to the phenomenon’s spooky, elusive nature like the folkloric fairies of old.

Dr. Dave Sentman of the University of Alaska, Fairbanks is one among a small group of researchers who have been studying these mysterious bursts of colored light. Although no one’s sure what sprites really are or what causes them, these scientists have learned that sprites contain a great deal of energy.

They’re associated with positive cloud-to-ground lightning discharges but unlike lightning, they direct their energy toward outer space into Earth’s ionosphere. In addition to light, sprites also radiate radio waves and even pulses of high-energy gamma rays.

[b][color=#0000FF]Sprites are members of a family of energetic, high-altitude phenomena occurring during thunderstorms. Credit: Abestrobi / Wiki[/color][/b]

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Sentman and other scientists flew above thunderclouds to study sprites up close. Seen nearly head-on, he describes them as colorless and about as bright as the aurora; younger members of the team with younger eyes spied the red color.

Sprites aren’t the only recently discovered electrical discharge to pop up in thunderstorms. Similar phenomena called elves, blue jets and halos have also been recorded, though sprites are more common and likely to be observed.

So how do you see one? Well, you could get lucky and find yourself in an airplane flying between storm clouds at 35,000 feet on a cross-country vacation. If so, turn off the overhead light and squeeze your face up against the window with your eyes on the stars above.

For ground viewing, you’ll need a night-time thunderstorm but not one that covers the sky and blocks the sprites from view. Best is a clear, starry sky with a line of thunderstorms crackling away along a distant horizon. That way you have a line of sight view across the cloud tops. The next time you notice flashes of lightning in an otherwise cloudless night sky, see what direction they’re coming from and drive to where you have an open view of that horizon. To improve your chances, avoid observing during twilight and in bright moonlight. You need dark skies and dark-adapted eyes. Fix your gaze a short distance above the line of thunderclouds while ignoring the bright flashes of lightning. You can use a piece of cardboard or the roof of your car to help block the storm if it’s too much of a distraction. Not all thunderstorms produce sprites, elves and the rest, so you’ll need patience to see one. The more you’re out under the stars, the better your chances.>>

[owlice]

Stars, Sprites, Gravity Waves and Meteors

Larger image here: http://www.heliotown.com/ASHCRAFT_SPgwM ... 41_9in.png

My primary subject currently is capturing lightning spawned red sprites and other transient luminous events. This near infrared image was a serendipitous capture of mesospheric gravity waves, red sprites, meteors, and the night sky looking eastward from New Mexico over Oklahoma on May 20, 2012 at 04:45:41 UT. The sprites and gravity waves were generated by very strong storm cells over 700 kilometers away from my observatory. I also have a video capture of this sprite cluster with two audio channels of radio emission at VLF-ELF and 2.5 MHz at the link below.
http://www.heliotown.com/Sprite_May_20_ ... 541UT.html
Modified full spectrum Canon XS, 50mm f1.8, ISO 1600, 4 second exposure.

Thomas Ashcraft : Heliotown Observatory : New Mexico

Originally here.

[owlice]

Click to view full size image

( Larger image here: http://www.heliotown.com/sprite_image_large.html

Update: Since posting yesterday I now also have a movie of these sprites with radio emission in slow-motion : http://vimeo.com/39703535

Massive Red Sprites over Oklahoma (with Radio Emissions)

This is a photograph of a jellyfish sprite which was followed immediately by a towering double carrot sprite. They occurred over western Oklahoma on March 30, 2012 at 0502:26 UTC during an enormously powerful thunderstorm. I was shooting continuous four second exposures with an infrared modified Canon XS DSLR. My observatory is located in New Mexico, 614 km away from where these large sprites occurred. Quite a distance away!

I was also lucky to capture these sprites with near infrared analog video and VLF-ELF radio and posted a movie here: http://vimeo.com/39658386

Clear skies to you folks,
Thomas Ashcraft
http://www.heliotown.com

Originally here.

[owlice]

Red Sprite (?) over a distant thunderstorm
http://www.emilivanov.com
Copyright: Emil Ivanov

Click to view full size image

This image was taken on Aug. 5th 2006 at 11:05 pm (Local Time) from Rozhen National Observatory during a heavy thunderstorm approximately 50 miles away.
For more than four years I thought that this is some kind of reflection over the thunder at the left middle, but yesterday a frend of mine suggested, that I might have captured a rare phenomenon of red sprite
The Moon was at about 20° above the horizon and 195°azimuth, which makes impossible this to be a direct Moon reflection.

Best regards

Emil

Originally here.

[owlice]

Red Sprites

Click to view full size image

After several years of hunting Sprites from my location in Denmark, it finally happened this week, the first danish Red Sprites ever photographed. Distance 350 km. (Thunder over The North Sea) Altitude about 50-90 km. There were 2 flashes, each produces 5-6 individual Red Sprites. Astro-modified Canon 5D II, 85mm f/1,2 lens in video-mode. To produce this picture, I used 2 video frames (Sprites) and 1 still-photo (fore-background).

©Jesper Grønne
http://www.astrophoto.dk

http://astrophoto.dk/gallery/albums/use ... s_2012.jpg

Originally here.

[owlice]

Red Sprites!
http://papics.eu/
Copyright: Péter I. Pápics

Click to view full size image

Originally here.

[owlice]

Red Sprites
http://indafoto.hu/godazoli/sprites/slideshow
Copyright: Zoltán Goda

Click to view full size image

Click to view full size image

Originally here.

[Qev]

Someone was asking for ELVES; here's a video that has some ELVES images and video sequences. I guess they're so short-lived people have a hard time getting a good image of them.

http://www.youtube.com/watch?v=18CohZfw2DU