Snowball comets

Comets & Lightning Jets

I recently picked up a second-hand book titled “The Big Splash” by Dr. Louis Frank of the University of Iowa. Although it was published in 1990, the issues it raised remain unresolved. The cover proclaims excitedly in large bold type: “A scientific discovery that revolutionizes the way we view the origin of life, the water we drink, the death of the dinosaurs, the creation of the oceans, the nature of the cosmos, and the very future of the Earth itself.” Dr. Frank comes with impeccable credentials. He was a full professor at 32 and at the time of writing the book was reputed to have “more instruments on more spacecraft than anyone else on the planet.”

The flyleaf of the book announces Frank’s interpretation of his discovery of mysterious holes punched in the uppermost reaches of the Earth’s atmosphere:

“Every minute, twenty 100-ton comets, made up of water and ice, slam into the Earth’s atmosphere. Each is about the size of a small house. According to Frank, these comets have been dumping water on the Earth for more than 4 billion years.”

Snowball comets

But as Frank found, “if you propose that something from out there is affecting us here and now, rather than millions of years in the past or millions of years in the future, beware the wrath of orthodox science. Science guards our isolation well.” See Not a snowball’s chance… in New Scientist vol 155 issue 2090 – 12 July 97, page 24.

Frank’s “proof” of his interpretation comes from a few images from orbiting spacecraft of glowing trails plunging toward the Earth, hundreds of kilometers above the surface. The glowing, ionized trails are said to emit the characteristic radiation of excited atoms and ions associated with water. The size of these “mini water comets” is thought to be about 5-20 meters diameter and density about 0.2g/cc, which would mean they are fluffy like a snowball.

Dr. Frank’s theory was developed from observations, beginning in 1981, of “holes” in dayglow images of the Earth returned by orbiting spacecraft. Dayglow is caused by sunlight exciting oxygen atoms 100 km high in the ionosphere, which then emit invisible ultraviolet light. Frank and a co-worker noticed that the day-glow images had small blemishes in the form of dark spots. After considerable effort to determine that the spots were not just noise or errors in transmission (since the spots were often no more than a pixel wide) it was concluded that the spots were real. They grew and faded quickly and moved in a prograde fashion like meteoritic dust.

The next question was what could cause the rapid extinction and recovery of the dayglow over a circle about 30 miles (48km) in diameter? Frank considered the possibility that a meteor could heat the air below a height of 100 km and cause it to rise into the dayglow level, quenching the glow there from atomic oxygen. A simple calculation showed that it would require meteors of 70 kg or more. They are rare. If the dayglow holes are too big to be caused by a meteor, Frank decided the cause “had to be” extraterrestrial molecules forming a UV absorbing layer above 100 km. To absorb the UV light from the oxygen atoms below, it must be a cloud of water vapour. This led to the notion that comets must be the cause of the dayglow holes because comets are believed to be composed largely of water ice.

The biggest hurdle for Frank’s theory is the number of holes measured, which implies that 20 comets per minute are striking the Earth. That’s 10 million comet-like objects per year, up to the size of a small house!

It is understandable that people in the Spacewatch program were very concerned that they haven’t seen anything of these impactors. Astronomers have rightly asked why it is that we have not detected this barrage by some other means. It should provide ample water to make the rare, stratospheric noctilucent clouds a continuous feature of our skies. It would be sufficient to give the Moon an appreciable atmosphere and cause seismic shocks and surface erosion there – none of which are apparent. Earth satellites would be expected to have detected the plasma disturbance in their wake. It is unlikely the military would have missed them. Frank’s answer to the objections is that the phenomenon is real and no one has come up with an alternative explanation. In his words, “There was no other reasonable explanation.” The new photographs of the few bright trails of objects entering the Earth’s ionosphere, reported widely, focussed attention on Frank’s theory but in no way constitute proof.

I have an alternative explanation for the ionospheric holes. My proposal was posted on the Internet on 2nd June 1997, under the title, “Comments on Interplanetary Snowballs.”

Frank noted two important characteristics of the ionospheric “holes.” First, the rate of occurrence is qualitatively similar to that for radar meteors (that is, meteors whose presence can be detected by radar echoes from their ionized trail through the atmosphere). Second is that the movement of the holes showed the prograde motion characteristic of meteoritic debris. These observations provide a strong link between the holes and simple meteors. But there is another essential element to the puzzle – the connection between ionized meteor trails and electrical discharge activity in the ionosphere. The meteor trail acts as a giant lightning rod that connects the conducting ionosphere to the upper atmosphere. If the earth is an electrical body in an electrical solar system, it is the equivalent of a temporary short-circuit of a giant capacitor. The current flowing along the meteor trail gives rise to the unexplained brilliance and long-lasting glows of some meteors. It causes them to disintegrate like an exploding capacitor, high in the atmosphere. The Tunguska explosion was probably the most noteworthy example of the effect.

In an earlier news item I expressed my opinion that the Columbia shuttle disaster was a result of a rare ionospheric discharge to the spacecraft. I am not convinced by an experiment that fired foam plastic at a Shuttle wing. Experiments performed with a desired outcome can usually be made to “succeed.” There are many infamous examples, along with some yet to be recognized. Airline pilots expressed disquiet about the lightning jets discovered above storms. No one knows what effect it might have on an airliner. However, due to the diffuse nature of the discharge and because airliners don’t leave much of an ionized wake to act as a lightning rod, there is probably nothing to fear. Anyway, airliners do their best to avoid flying above electrical storms. It should be noted also that meteors and space shuttles entering the atmosphere from above and descending rapidly through many tens of kilometres could remove the need for a 10 km high storm below to offer a preferred electrical path through the atmosphere to the ground.

My hypothesis is a logical extension of my earlier explanation of red sprites, blue jets and elves. The recent discovery of giant lightning jets [see below] provides even stronger evidence for such a link.

One practically unknown characteristic of lightning is its ability to compress and accelerate atmospheric ions along the discharge channel from regions of high pressure to regions of lower pressure. In other words, it creates a roughly vertical jet of warmer air. These fountains can sometimes be seen from aircraft flying above electrical storms, protruding as filaments of cloud. Eric Crew, a colleague of the British electrical researcher, Dr. Charles Bruce, has suggested that such jets of warm, moist air into the stratosphere may be the cause of very large hailstones. The warm jet phenomenon has been reported at ground level: In July 1971 a retired general practitioner, Dr L.H. Worth, climbed to the rounded summit of the Puy Mary, 1770m, in central France. He could see a storm in the valley below him about 3km away and he heard the thunder. A few seconds later he felt a blast of hot air, so powerful that he had to lean against it, and this occurred three times in the next few seconds. That it was not an imaginary or hallucinatory experience is shown by the fact that people on the mountain near him rushed away for shelter.


From a New Scientist report [vol 178 issue 2401 – 28 June 2003, page 16] by Hazel Muir:

“Scientists in Taiwan have filmed five enormous lightning bolts they are calling “gigantic jets” reaching an altitude of 90 kilometres. The jets could play a vital role in dissipating the electrical charge that thunderstorms transport to the upper atmosphere.”


Comment: It’s true that thunderstorms transport charge in the form of electrons to the upper atmosphere. However, it is not true that thunderstorms somehow need to “dissipate” their charge to feed the ionosphere. Storm clouds can be regarded simply as an impurity in the atmosphere that serves to increase the conductivity between the charged earth and the differently charged ionosphere. The result is that electrical breakdown occurs preferentially where the clouds stretch highest. Without them we would suffer much more rare but devastating “bolts from the blue,” or giant electrical tornadoes like those on cloudless Mars.

“..The jets, which lasted a few hundred milliseconds, look like hybrids of a sprite and a blue jet, with a slim lower section fanning out at the top (Nature, vol 423, p 974). ..In September 2001, Victor Pasko of Penn State University at University Park spotted a similar hybrid jet over the ocean near Puerto Rico. Su’s work confirms that they are a new class of lightning. Receivers in Japan and Antarctica also detected extremely low-frequency radio waves from the jets – a sign that they were electrical discharges between the ionosphere and the clouds. Su thinks they compensate for the effects of thunderstorms, which constantly drive an upward current that keeps the ionosphere positively charged with respect to the ground.

Comment: Su’s theory is guesswork since experts on lightning do not know what is “cause” and what is “effect” when looking at the electrical activity associated with storms. He is a victim of the reductionist approach to science where no one can see the big picture. Certainly, no scientist has considered that the electrical storm may be an effect caused by the giant lightning above! Nor have they considered that it is the Earth that is charged negatively with respect to the solar plasma, which means that the ionosphere appears to be mysteriously positively charged to an Earthbound observer.

”He [Su] now wants to know how common gigantic jets are. And he is mystified about why the six jets seen to date all occurred above tropical oceans. An observing programme in the Rocky Mountains has picked up nearly 10,000 sprites since 1992, but not a single gigantic jet. Su speculates that the high salinity of tropical oceans might trigger gigantic jets, although he is not sure how. ‘It reminds us that our understanding of the Earth’s environment is not as complete as we would like to believe,’ he adds.”

Comment: Precisely! It has been found that lightning occurs preferentially over the oceans and in the lower latitudes. The salty oceans of Earth make an ideal conductor to transfer charge from the Earth to space. The Earth’s continents are not such good conductors and inhibit the flow of charge. However, some continental regions are better conductors than others, resulting in unusual storm and tornado activity there – like that seen in parts of the U.S. The latitudinal effect has been demonstrated in laboratory electrical plasma discharges to a magnetized sphere.

Pasko agrees. ‘This field is in its infancy,’ he says in an accompanying article in Nature. That could change soon, however, as there are several proposed projects to observe lightning and sprites globally from space. That would reveal just how common gigantic jets really are.

The jets might have interesting effects on the chemistry of the atmosphere, adds Pasko. Their electric fields could accelerate electrons enough to dissociate oxygen molecules, triggering a chain of reactions that leads to ozone formation.”

Comment: That is likely. However, to return to the case of Louis Frank’s mysterious ionospheric holes, it seems plausible that giant lightning discharges could be triggered by the ionized trail created by a meteor. The result would be a fountain of un-ionized air from lower levels that punches through the airglow level. It would cause a sudden decrease in the airglow until the newly exposed atmospheric gases can be dissociated by solar radiation. The tops of the giant lightning jets reaches the altitude of the airglow layer and their dimensions are of the right order to explain the diameters of the ionospheric holes. I expect the study of sprites from space to clear up Louis Frank’s mystery.

Postscript: This model of the electrical interaction between planetary atmospheres and comets or large meteors has a lot to tell us about the strange effects seen when comet Shoemaker-Levy 9 struck Jupiter. But that’s another story.

Wal Thornhill

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