28 7 / 2013
Spectacular Sprites - Ashcraft captures a large sprite hanging over West Kansas. Photos by Thomas Ashcraft
In the blink of an eye, an enormous bright red light flashes above a thundercloud, spreading energetic branches that extend five times taller than Mount Everest and look like jellyfish tendrils and angel’s wings.
These mysterious phenomena are known as Transient Luminous Events (TLEs), and are usually invisible to the naked eye because they happen on millisecond timescales, too fast to be seen. They occur between 50 to 100 kilometers above the ground, a long-ignored area of the atmosphere that is too high for aircraft but too low for satellites to investigate. There, the thin air interacts with strong electrical fields to ionize molecules and create arcing plasmas.
These spectacles are relatively new to science. Pilots had reported enigmatic bright flashes throughout the 20th century, but their anecdotal evidence didn’t amount to proof. The first image of a TLE was captured accidentally in 1989 when a University of Minnesota professor aimed a low-light TV camera at the sky to film a rocket launch. Replaying the tape later on, Professor John R. Winckler saw brilliant columns of light extending from the tops of storm clouds. Hearing of the finding, NASA officials immediately ordered a review of video tapes taken from the space shuttle that looked at lightning events on Earth. They found dozens more examples of TLEs, and later scientists have been recording them ever since.
"One of the neatest things about TLEs is that first image in 1989 was just a serendipitous capture," said amateur radio astronomer Thomas Ashcraft, who has been photographing the events for several years.
Using a relatively simple camera and radio dish, Ashcraft has seen a whole bestiary of odd TLE phenomena. The most common are sprites, tall and highly structured bursts of light that appear above thunderstorms. They ionize the nitrogen in our atmosphere, causing a red glow. Often, they happen in conjunction with “Emissions of Light and Very Low Frequency Perturbations due to Electromagnetic Pulse Sources,” also known as ELVES, which are enormous halos of light that shoot outward to cover up to 500 kilometers in a millisecond. Though they are too short-lived to see, ELVES can produce bright afterglows that some people have mistaken for UFOs. Other TLEs have names like blue jets and trolls.
Above: Close-Up Sprite - The firework details of a sprite emerge in this image, captured looking over Taos, New Mexico in 2012.
To deliver great TLE shots, Ashcraft first checks radar maps of the local area around his observatory in Santa Fe, New Mexico. Red spots on such maps indicate strong lightning cells, which increases the probability of sprite activity. Because the phenomena are mostly visible in near infrared wavelengths, he uses a modified off-the-shelf DLSR camera from which he removed the clear glass filter covering the CCD that blocks infrared light.
By taking continuous three-second exposures, Ashcraft records thousands of pictures each night. He then goes through the catalog looking for a sprite to appear. If he spots something, he can check a video camera that he has running during the night to see if captured more detail there. He shares his most interesting findings with other sprite observers, who may chime in with their own pictures from other positions.
From Santa Fe, Ashcraft says he can usually catch sprites up to 1,000 kilometers away. “I can see big storms out over the Great Plains, usually beyond Oklahoma City and into Nebraska,” he said. “After that, the curvature of the Earth gets in the way.”
Using a radio dish, Ashcraft also captures extremely low frequency emissions that the TLEs give off. He converts these into sound files, which can be heard in his videos, and can help researchers pick out details they might otherwise miss.
A lot of research regarding TLEs is still cutting-edge science, said Ashcraft. Only in recent years have scientists aimed high-speed cameras capable of capturing thousands of frames per second to study the spectacles in detail. While researchers had originally hypothesized that the phenomena were starting at the tops of thunderclouds, fast-motion videos prove that TLEs start as luminous spheres and then shoot upwards and downwards at the same time.
To read the rest of the story and look at more photos, click here.
04 4 / 2013
28 11 / 2012
25 11 / 2012
24 11 / 2012
24 11 / 2012
21 6 / 2012
19 6 / 2012
Taking cues from the firefly, a Dutch electronics company has created a product called “Bio-light”—an eco-friendly lighting system that uses glowing, bioluminescent bacteria. They’re not powered by electricity or sunlight, but by methane generated by the company’s Microbial Home bio-digester that processes anything from vegetable scraps to human waste. The living bacteria are fed through silicon tubes, and as long as they’re nutritionally-fulfilled, they can indefinitely generate a soft, heat-free green glow using the enzyme luciferase and its substrate, luciferin. They’re kept in hand-blown glass bulbs clustered together into lamps, but you can’t light up your house with them yet—the glow isn’t nearly bright enough to replace conventional artificial lights. They do, however, get people to think about untapped household energy sources and how to make use of them. The company, Phillips, also envisions the use of these Bio-lights outside the home—for nighttime road markings, signs in theatres and clubs, and even biosensors for monitoring diabetes.
14 6 / 2012
More science/photo experiments from Caleb Charland. Couldn’t resist.
This is a simple battery made from a stack of coins and saltwater-soaked paper. A grade-school science experiment, but a photo that captures the simple “wow” feeling of an experiment, don’t you think?
FastCo.Design has a gallery that you won’t want to miss. He is one of the most creative capturers of curiosities working out there, if you ask me. And no Photoshop on any of them!
10 6 / 2012
In November 1971, we were locked in yet another space race, albeit a quieter one. Americans had already begun to grow bored with the Apollo program, as the final two missions were to be launched in 1972, those primarily being very expensive geology expeditions.
Then Mariner 9 was launched. We were in a race with the USSR to put a spacecraft in orbit around another planet. In November of 1971, we did it. I’m not sure that Americans were by any means excited about it, but they should have been. Just as we must stay excited about our progress yet to come.
Ray Bradbury joined Arthur C. Clarke, Carl Sagan and others at NASA’s Jet Propulsion Labs in Pasadena to commemorate the mission’s success. Here he reads his poem "If Only We Had Taller Been", an ode to exploration, and a fitting tribute to his legacy as a writer and dreamer. In full above (with a captivated Sagan included) and excerpted below:
O, Thomas, will a Race one day stand really tall
Across the Void, across the Universe and all?
And, measure out with rocket fire,
At last put Adam’s finger forth
As on the Sistine Ceiling,
And God’s great hand come down the other way
To measure Man and find him Good,
And Gift him with Forever’s Day?
I work for that.
Short man. Large dream. I send my rockets forth
between my ears,
Hoping an inch of Will is worth a pound of years.
Aching to hear a voice cry back along the universal Mall:
We’ve reached Alpha Centauri!
We’re tall, O God, we’re tall!
(via Boing Boing)
06 6 / 2012
Venus Enters the Solar Disk
Here’s a video of Venus as it crosses over in front of the Sun’s face. The true scale of our solar system is represented here, in amazing clarity. Venus looks as if it’s going to be swallowed up by the Sun, burned to a planetary crisp … but then you remember that it’s still 108 million kilometers away.
(images captured from NASA’s transit feed)