ENTIRELY NEW FORMS OF LIGHTNING HAVE BEEN DISCOVERED UP TO 1000 TIMES BIGGER THAN ANY BOLT PREVIOUSLY SEEN. WHILE NORMAL LIGHTNING FIRES DOWN BELOW CLOUDS, THESE GIANT BOLTS SHOOT UP, STUNNING EXPERTS WITH IMAGES OF LIGHTNING 80 KILOMETRES HIGH. THIS LIGHTNING, SIX TIMES MORE POWERFUL THAN PASSENGER PLANES ARE DESIGNED TO WITHSTAND, MAY BE THE REAL KILLER IN A SPATE OF BAFFLING AIR DISASTERS. Camera takes photo. AND FOR THE FIRST TIME WE CAN REVEAL THE PHOTOGRAPH THAT SPARKED A SECRET NASA ENQUIRY. WAS THIS THE PROOF THAT A HIGH ALTITUDE LIGHTNING STRIKE CAUSED THE CRASH OF THE SPACE SHUTTLE COLUMBIA? Title card: MEGA-LIGHTNING NARRATOR: EACH DAY, THE EARTH IS SHAKEN BY 8 MILLION BOLTS OF THE SKY'S MOST POWERFUL FORCE: LIGHTNING. Bolt of lightning. NARRATOR: ENERGY FROM ONE BOLT EXPLODES IN SPLIT SECOND, BUT COULD POWER A HOUSEHOLD FOR HALF A YEAR. AT ANY TIME, 1800 STORMS PUMMEL OUR PLANET. EACH ONE IS A GIANT BATTERY. INSIDE A STORM, WATER TURNS TO HAIL. FAILLING ICE CRASHES ON RISING DROPLET, CREATING STATIC ELECTRICITY. CHARGES OF UP TO 100 MILLION VOLTS BUILD UP. ARCS OF ELECTRICITY FIRE OUT. THIS IS LIGHTNING. MORE THAN 90 PERCENT OF ALL BOLTS FIRE WITHIN CLOUDS. BUT A HIGHLY CHARGED STORM WILL FIRE A CASCADE OF ELECTRICAL CHARGE TO EARTH, DRAWN TO THE HIGHEST POINT. A TREE OR A BLADE OF GRASS CAN TRIGGER LIGHTNING, OR EVEN A PERSON. EACH YEAR, 100O PEOPLE AROUND THE WORLD DIE FROM DIRECT HIT. A LIGHTNING BOLT IS ONLY 3 CM WIDE. BUT AT 33,000 DEGREES CELCIUS, IT IS HOTTER THAN THE SURFACE OF THE SUN. CGI lightning. NARRATOR: THIS HEAT EXPANDS THE SURROUNDING AIR, WHICH EXPLODES OUTWARDS AS THUNDER, THE SOUND OF LIGHTNING. CGI lightning strike. NARRATOR: A LIGHTNING FLASH TRAVELS AT THE SPEED OF LIGHT; IT'S THUNDER TRAVELS MUCH SLOWER. THE SHORTER THE TIME BETWEEN THE FLASH AND THE THUNDER, THE CLOSER THE LIGHTNING BOLT. FEW CLOUD TO GROUND STRIKES ARE LONGER THAN THREE KILOMETRES. AND TEXTBOOKS SAID NO LIGHTNING COULD EXIST ABOVE THE CLOUDS. Cloud to ground lighting with measuring rod. Walt Lyons on balcony. NARRATOR: BUT THEN WEATHERMAN WALT LYONS AIMED HIS CAMERA ACROSS THE COLORADO PLAINS ON JULY 6, 1993. Mountains through Walt's eye glasses NARRATOR: WHAT HE SAW OVERTURNED 200 YEARS OF SCIENTIFIC CERTAINTY IN AN INSTANT. Green sprites images. NARRATOR: HE FILMED THESE VIDEO IMAGES. THEY SHOW LIGHTNING 80 KILOMETRES HIGH AND 40 KILOMETRES WIDE FIRING ABOVE THE CLOUDS. THEIR EXISTENCE HAD BEEN DISMISSED AS FANTASY. THEIR DISCOVERY SHEDS NEW LIGHT ON WHAT HAS BEEN CAUSING AIRPLANES TO FALL FROM THE SKY. Sunrise. Stuart Beecher lights a pipe. NARRATOR: THE DISCOVERY OF MEGA-LIGHTNING BEGAN WITH ORDINARY PEOPLE SEEING EXTRAORDINARY THINGS. Stills of Beecher in name separated by light flashes. NARRATOR: IN 1969 STUART BEECHER WAS DEFENDING A MORTAR PIT OUTSIDE SAIGON IN SOUTH VIETNAM, WHEN A STORM BROKE. Stuart Beecher: There was this giant flash of lighting that reached from the ground through the base of the cloud, completed illuminated the cloud, and out the top from the ground, in this beautiful double helix pattern, that seemed to just go on forever. It was just like it was going straight into space. Amateur photo of above cloud lightning. STRAPLINE: Photograph: Tudor Williams NARRATOR: THERE HAD EVEN BEEN PHOTOGRAPHS. THIS WAS TAKEN AT MT ISA IN AUSTRALIA, IN 1968. SCIENTISTS HAD IGNORED THE SIGHTINGS. Skeet Vaughan flying. NARRATOR: SKEET VAUGHAN, A SENIOR NASA ENGINEER, MET A WITNESS WHO HAD SEEN GIANT LIGHTNING IN 1981. AS A TRAINED PILOT, VAUGHAN TOOK THE SIGHTING SERIOUSLY. STRAPLINE: Skeet Vaughan - NASA Engineer 1959-96 Skeet Vaughan: I wrote an article in one of the flying magazines, and asked pilots to tell me if they'd seen any unusual lightning, or anything out of the ordinary. A number of pilots, about 19 of them, sent me letters telling me about this kind of a thing. Pilot walks to letterbox. NARRATOR: PILOT LARRY PARTRIDGE WAS ONE OF THOSE WHO WROTE TO VAUGHN, REVEALING THAT HE'D SEEN GIANT LIGHTNING ABOVE THE CLOUDS GOING UP, AND NOT DOWN. STRAPLINE: Larry Partridge, pilot. Larry Partridge: All of a sudden, POW! Just a split second, this huge bolt of lightning came out of the top and disappeared into deep blue space. The captain turned to me and said, wide eyed, and said did you see that? And so I said yes, and so we turned and told the flight engineer, and he said, that's impossible. Lightning doesn't go up. CGI blue jet. Pilot Robin May flying. STRAPLINE: Robin May - pilot Robin May: A Strike of lightning appeared to come from the top of the cloud, went straight up, bright white, for ten or 15 thousand feet, then broke up into a lot of little fingers that went through the different colours of the spectrum, and disappeared off into space. CGI of sprite to show what Larry sees through window of plane. Skeet Vaughn: But most of the pilots had said they'd never talk to people about this, they were somewhat reluctant to, in the case that they