"Wow."

That was astronaut Tammy Jernigan's stunned reaction last night when she viewed a photo of what appears to be space shuttle Columbia getting zapped by a purplish electrical bolt shortly before it disintegrated Saturday morning.

Former astronaut Tammy Jernigan

"It certainly appears very anomalous," Jernigan told the San Francisco Chronicle. "We sure will be very interested in taking a very hard look at this."

The photo was one of five captured by an amateur astronomer in San Francisco who routinely snaps pictures of shuttles when they pass over the Bay area.

The pictures were taken just seven minutes before Columbia's fatal demise.

The Chronicle reports that top investigators of the disaster are now analyzing the startling photograph to try to solve the mystery.

The photographer continues to request his name be withheld, adding he would not release the image publicly until NASA has a chance to study it.

"[The photos] clearly record an electrical discharge like a lightning bolt flashing past, and I was snapping the pictures almost exactly ... when the Columbia may have begun breaking up during re-entry," the photographer originally told the paper Saturday night.

Late yesterday, the space agency sent Jernigan – a former shuttle flyer and now manager at Lawrence Livermore Laboratories – to the astronomer's home to view the image, and have the Nikon camera brought to Houston today.

It was slated to be flown to the Johnson Space Center by a NASA T-38 jet this morning.

Jernigan reportedly asked the astronomer about the f-stop setting on his lens, and how long he kept the shutter open – apparently some four to six seconds. A tripod was used to steady the camera, and the shutter was triggered manually.

"In the critical shot," states the Chronicle, "a glowing purple rope of light corkscrews down toward the plasma trail, appears to pass behind it, then cuts sharply toward it from below. As it merges with the plasma trail, the streak itself brightens for a distance, then fades."

"I couldn't see the discharge with my own eyes, but it showed up clear and bright on the film when I developed it," the photographer previously said. "But I'm not going to speculate about what it might be."

David Perlman, science editor for the Chronicle, called the photos "indeed puzzling."

"They show a bright scraggly flash of orange light, tinged with pale purple, and shaped somewhat like a deformed L," he wrote.

Space shuttle Columbia's rollout to the launchpad (NASA photo)

Jernigan no longer works for NASA, though she's a veteran of five shuttle missions in the 1990s. Ironically, on her final flight, the orbiter's pilot was Rick Husband, who was at the helm at 9 a.m. EST Saturday when Columbia broke apart during re-entry into the atmosphere.

"He was one of the finest people I could ever hope to know," Jernigan said.

According to her NASA biography, Jernigan graduated from Stanford in 1981 with a bachelor's degree in physics. She went on to earn master's degrees in engineering science and astronomy from Stanford and UC-Berkeley respectively. She also holds a doctorate in space physics and astronomy from Rice University.

She's spent over 63 days above the Earth, completing 1,000 orbits, and having walked in space for nearly eight hours during her final mission aboard shuttle Discovery in 1999.

Before flying on shuttles, she was a research scientist in the theoretical studies branch of NASA Ames Research Center, working on the study of bipolar outflows in the region of star formations, gamma ray bursters and shock-wave phenomena in the interstellar medium.

Regarding the Columbia disaster, the space agency is additionally investigating reports of possible remnants found in the West, including California and Arizona.

"Debris early in the flight path would be critical because that material would obviously be near the start of the events," said Michael Kostelnik, a NASA spaceflight office deputy.

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SPRITES

Lightning between
Earth and Space

Scientists discover a curious
variety of electrical activity going on
above thunderstorms

by Stephen B. Mende, Davis D. Sentman and Eugene M. Wescott

ILLUSTRATIONS:

Since ancient times, lightning has both awed and fascinated people with its splendor and might. The early Greeks, for instance, associated the lightning bolt with Zeus, their most powerful god. And even after a modern understanding of the electrical nature of lightning developed, certain mysteries persisted. Many observers described luminous displays flickering through the upper reaches of the night sky. Some of these curiosities could be explained as auroras or weirdly illuminated clouds, but others were more baffling. In particular, pilots flying through the darkness occasionally observed strange flashes above thunderstorms. But the scientific community largely regarded these reports as apocryphal--until 1990, when John R. Winckler and his colleagues at the University of Minnesota first captured one of these enigmatic phantoms using a video camera. Their images revealed lightning of a completely new configuration.

Lightning

Winckler's achievement ushered in a flurry of activity to document such high-altitude electrical phenomena. And hundreds of similar observations--from the space shuttle, from aircraft and from the ground--have since followed. The result has been a growing appreciation that lightninglike effects are not at all restricted to the lower atmospheric layers sandwiched between storm clouds and the ground. Indeed, scientists now realize that electrical discharges take place regularly in the rarefied air up to 90 kilometers above thunderclouds.

It is remarkable that these events, many of which are visible to the naked eye, went undiscovered for so long. In retrospect, the existence of some form of lightning high in the atmosphere should not have come as a surprise to scientists. They have long known that well above the turbulent parts of the atmosphere, ultraviolet rays from the sun strike gas molecules and knock electrons loose from them. This process forms the ionosphere, an electrically conductive layer that encircles the earth. Large differences in voltage can exist between storm clouds and the ionosphere, just as they do between clouds and the ground. Impelled by such enormous voltages, lightning can invade either zone when the air--which is typically an electrical insulator--breaks down and provides a conductive path for electric currents to follow.

Electromagnetic Pulses

Because the atmosphere becomes less dense with increasing altitude, the lightning that happens at greater heights involves fewer air molecules and produces colors not seen in typical discharges. Usually they appear red and are only faintly visible. Thus, researchers must employ sensitive video cameras to record these events against the backdrop of the darkened night sky. The feebleness of the light given off and the transient nature of such emissions combine to present severe technical challenges to the researchers involved in studying these ghostly atmospheric events. Nevertheless, in just a few years investigators have made considerable progress in understanding them.

Elves

Blue Jets

Two of us (Sentman and Wescott) have mounted airborne research campaigns using specially outfitted jets. All three of us (and many others) have also studied high-altitude electrical activity from the ground: for example, we gather every year at the invitation of Walter A. Lyons, a scientist at ASTeR in Fort Collins, Colo., and set up our equipment in his backyard laboratory--a site that offers an unobstructed view of the night sky over the thunderstorms of the Great Plains. (The images on pages 56 and 58 are views from this informal observatory.) Umran S. Inan and his colleagues at Stanford University have also recorded low-frequency radio waves from Lyons's home, measurements that have helped them to formulate theoretical models.

Gamma-Ray and
X-Ray Events

The newly discovered electrical events of the upper atmosphere fall into four categories. Two types of high-level lightning, termed sprites and elves, appear (despite their fanciful names) to be manifestations of well-understood atmospheric physics. The causes for the other two varieties, called blue jets and gamma-ray events, remain more speculative. But our research group and many others around the world are still amassing our observations in hopes of deciphering the physical mechanisms driving these strange occurrences as well. Until that time, we must admit something like the ancient sense of awe and wonder when we contemplate these curious bursts of energy that dance through the ethereal world between earth and space.

Further Reading

DISCOVERY OF INTENSE GAMMA-RAY FLASHES OF ATMOSPHERIC ORIGIN. G. J. Fishman, P. N. Bhat, R. Mallozzi, J. M. Horack, T. Koshut, C. Kouveliotou, G. N. Pendleton, C. A. Meegan, R. B. Wilson, W. S. Paciesas, S. J. Goodman and H. J. Christian in Science, Vol. 264, pages 1313-1316; May 27, 1994.

PRELIMINARY RESULTS FROM THE SPRITES94 AIRCRAFT CAMPAIGN, 1: RED SPRITES. D. D. Sentman, E. M. Wescott, D. L. Osborne, D. L. Hampton and M. J. Heavner in Geophysical Research Letters, Vol. 22, No. 10, pages 1205-1208; May 15, 1995.

PRELIMINARY RESULTS FROM THE SPRITES94 AIRCRAFT CAMPAIGN, 2: BLUE JETS. E. M. Wescott, D. Sentman, D. Osborne, D. Hampton and M. Heavner in Geophysical Research Letters, Vol. 22, No. 10, pages 1209-1212; May 15, 1995.

ELVES: LIGHTNING-INDUCED TRANSIENT LUMINOUS EVENTS IN THE LOWER IONOSPHERE. H. Fukunishi, Y. Takahashi, M. Kubota, K. Sakanoi, U. S. Inan and W. A. Lyons in Geophysical Research Letters, Vol. 23, No. 16, pages 2157-2160; August 1, 1996.

Science

Geophysical Research Letters

Walter Lyons' Handy Weather Answer Book

Red Sprites and Blue Jets

The Authors

STEPHEN B. MENDE, DAVIS D. SENTMAN and EUGENE M. WESCOTT have spent much of their time during recent years investigating curious electrical activity of the upper atmosphere. Mende received a Ph.D. in physics from Imperial College at the University of London in 1965. From 1967 to 1996 he worked for Lockheed Palo Alto Research Laboratory. Mende is currently a fellow at the space sciences laboratory of the University of California, Berkeley. Sentman studied space physics under James Van Allen at the University of Iowa, where he earned his doctorate in 1976. After 14 years at the University of California, Los Angeles, Sentman joined the physics department at the University of Alaska-Fairbanks, where he now serves on the faculty. Wescott received a Ph.D. in geophysics from the University of Alaska-Fairbanks in 1964. He worked for three years at the National Aeronautics and Space Administration Goddard Space Flight Center in Maryland before returning to the University of Alaska-Fairbanks as a professor of geophysics.

LINK

SPRITES are high-altitude luminous flashes that take place above thunderstorms in a part of the atmosphere called the mesosphere. Although sprites are usually rare, some storms can spawn them frequently. Typically the upper parts of clouds are charged positively and the lower parts negatively. Most often, it is the negative base of the cloud that flashes to the ground. But at times the upper, positive part can discharge directly to the earth, producing a lightning flash of exceptional intensity. About one out of 20 such positive cloud-to-ground lightning bolts are sufficiently energetic that they spawn sprites. These examples, recorded from the ground with a monochromatic video camera, have been colorized to match a color image obtained from an aircraft.

LINK

LIGHTNING (below, left) usually carries negative charge from the base of a cloud down to the earth. Sometimes powerful strokes (center) cause the positive charge that had built up near the top of the cloud to disappear abruptly. The large electrical field (gradation in color) created between the cloud top and the ionosphere pulls electrons upward, where they collide with gas molecules. If the electrical field is sufficiently strong and the air sufficiently thin, the electrons will accelerate unimpeded and reach the velocity needed to transfer their kinetic energy to the electronic structure of the molecules with which they collide, raising such molecules to an "excited state." The excited molecules give away their newly acquired energy by the emission of light, causing sprites (below, right). They typically span from 50 to 90 kilometers altitude.

LINK

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Lightning between Earth and Space

Lightning between
Earth and Space