[b]OLD NEWS[/b] - [i]April & May[/i]

In 1859 Richard C. Carrington, a wealthy bachelor of 33, spent his days working as an amateur astronomer at his home observatory in Redhill, twenty miles south of London, England.  On September 1 that year at 11:18 in the morning, Carrington was observing sunspots when he saw something extraordinary--gigantic explosions erupting from the sun's surface.

Carrington's telescope was projecting an image of the sun onto a painted board that was crosshatched with rules lines.  A dark filter over one of the telescope's lenses dimmed the image that appeared on the board, where the sun's face was reduced to a dull yellow disk, about twelve inches wide and speckled with brown sunspots.

The two explosions were so intensely bright that Carrington at first assumed that direct sunlight must be leaking through the pinhole defects in the filter.  He shook the filter, expecting to see the two spots vibrate violently, but they did not even jiggle.  Instead they grew larger, expanding to kidney-shaped pools of fierce brilliance on the dark face of a sunspot.

Carrington then realized that he was seeing two fireballs, each about the size of planet Earth, that were erupting from the sun into space.  Judging by the brightness of the spots on his painted board, Carrington guessed that the fireballs must be at least twice as hot as the normal surface of the sun.

No other astronomer had ever reported seeing explosions on the sun.  The importance of what he was seeing left Carrington stunned for a few seconds; then he was startled by the realization that he might be the only astronomer in the world who was witnessing the explosion.  If nobody else saw this unprecedented phenomenon, then other scientists would greet Carrington's report with skepticism.

After jotting down the time, Carrington left the observatory and ran into the main wing of his house calling for his servants.  He later wrote: "Seeing the outburst to be very rapidly on the increase, and being somewhat flurried by the surprise, I hastily ran to call someone to witness the exhibition with me, and on returning within 60 seconds, was mortified to find it was already much changed and enfeebled."  He could only hope that some other astronomer, somewhere in the world, had also noticed the eruptions.

Within five minutes of their appearance, the solar flares had completely disappeared.  Carrington calculated that during the short time that they had blazed, the flares had migrated 35,000 miles across the face if a sunspot, moving at a speed of 420,000 miles per hour.

Carrington made a sketch of what he had seen, and he recorded all the details he could remember.  He remained at his observatory for the rest of the daylight hours of September 1, watching for another flare, but none appeared.  The daylight hours of September 2 were similarly uneventful, but when the sun set on September 2, Carrington saw something unusual.  The night sky was illuminated by auroras.

These displays of heavenly lights normally occur in the earth's Arctic and Antarctic regions, but the auroras of September 2, 1859, lit up all of the British Isles.  [i]The Times[/i] of London reported: "The phenomenon, as seen in Cheale, Cheshire, was sufficiently luminous, notwithstanding some overspreading clouds, to permit the reading of print letters 1/8 of an inch in size."

The auroras appeared not only over Europe, but also in most other parts of the world, including both the northern and southern hemispheres.  In many tropical and subtropical regions, auroras appeared for the first time in recorded history.  In New Orleans [i]The Daily Picayune[/i] described the heavenly light as follows:

"The horizon from north to north east became of a deep crimson hue, which expanding slowly, made the sky appear as if lighted by a Bengal fire. . . .  At first it was supposed that some great conflagration had taken place on the outskirts of the city, but it was soon recognized that no natural fire could produce this particular hue. . .  Crowds of people gathered at the street corners, admiring and commenting upon the singular spectacle.  Many took it to be the sign of some great disaster or important event. . . .  Several old women were nearly frightened to death, thinking it announced the end of the world, and immediately took to saying their prayers."

In Kingston, Jamaica, observers believed that the red glow to their north meant that the entire island of Cuba was being consumed by fire.  On the island of San Salvador, it was reported that "the red light was so vivid that the roofs of the houses and the leaves of trees appeared as if covered in blood."

At the same time that these auroras appeared in the tropics, telegraph communication was disrupted in every technically advanced nation.  Telegraph operators in many places suffered severe shocks: there were no fatalities, but one telegrapher in Philadelphia was knocked unconscious.  Elsewhere, telegraph equipment caught fire, filling offices with smoke.  Worried about damage to their equipment, operators in various places disconnected the batteries that powered their telegraphs--after which some of them discovered that the equipment continued to send messages anyway, powered by the electromagnetic currents surging through the atmosphere.

The first appearance of the auroras probably made Carrington suspect that they might be connected to the recent explosions on the sun.  His main concern, however, was his anxiety to learn whether other astronomers had witnessed the solar flares.  Shortly after September 2, Carrington left Redhill and traveled to the government-sponsored observatory at Kew, to consult with the staff there.

King George III, and amateur astronomer, had built Kew Observatory in 1768-1769.  Its telescopes were housed in a three-story, white stone building, and Carrington had to walk up a very long driveway to reach the main door.  He knew that astronomers at Kew had been photographing the sun at regular intervals, but when his colleagues welcomed him into their observatory, he was disappointed to learn that nobody at Kew had captured the solar explosion on film; in fact, nobody had even seen it.

Kew Observatory was equipped with a magnetometer, a device that created a continuous record of changes in the local magnetic field, so Carrington asked to see the scroll of developed photographic paper that recorded what the device had measured on September 1 and 2.  He was thrilled to discover that the magnetometer had recorded an abrupt change at exactly the time that he had witnessed the solar flare on September 1.  The Earth's magnetic field had been disrupted so violently that het line had been knocked right off the scroll for four minutes.

Carrington saw that after this abrupt disruption, the line on the scroll had returned to its normal straight, horizontal position for the next eighteen hours.  At that point, a raging magnetic storm had commenced, making the line on the scroll jerk crazily for several days.

Carrington suspected that his magnetic storm had caused the unusual auroras that had recently enveloped Earth.  According to the evidence of the scroll, the magnetic storm had commenced during daylight hours in England, but Carrington eventually determined that it had commenced at the same time that the auroras had first been sighted on the dark half of the globe.  And the storm had ended when the auroras faded from the skies outside the polar regions.

The scrolls in Carrington's hands vastly increased the scientific importance of his discovery: he had found evidence that the sun could influence Earth in ways that nobody had imagined.  If he could persuade other astronomers to believe him, then their discipline would change.  Instead of devoting most of their efforts to calculating the effects of gravity on heavenly bodies, astronomers would henceforth need to expand their research to include electromagnetic phenomena.

Desperate for some independent corroboration, Carrington announced that he had witnessed something extraordinary on the sun on September 1.  He sent out a plea to all of his fellow members of Britain's Royal Astronomical Society, asking if anybody else had seen something unusual that day.

To Carrington's joy, a society member in Kent, R. Hodgson, reported that he had witnessed "a very remarkable phenomenon" on September 1.  Carrington did not ask for any details from Hodgson.  He asked him to keep his observations secret for the time being, but to prepare a report for the Royal Society.

On November 11, 1859, the Fellows of the Royal Astronomical Society gathered at Somerset House in London to hear Carrington and Hodgson present their independent reports.  Carrington spoke first, showing his sketch of the flares in the sunspot.  Hodgson then rose to report his own observations.  He said that he had seen "bright light on the sun" at the same time as Carrington, but he confessed he had been too surprised to make an accurate drawing.  He presented a rough sketch, which essentially confirmed Carrington's report.

Although Carrington suspected that the solar flares had caused the auroras that followed them, he had no way of proving it.

During the hundred and fifty years since Carrington witnessed the phenomena, astronomers have learned that solar flares are fairly commonplace events.  Flares can be accompanied by bursts of extremely high-energy radiation that hit the Earth at the same time that light from the flares becomes visible.  Flares can also result in "coronal mass ejections" of charged particles from the sun, which do not reach Earth until hours or days after the appearance of flares.  As Carrington suspected, when these particles strike Earth's atmosphere, they cause auroras.

In recent decades, scientists have discovered that radiation and particles from solar flares can damage satellites and power grids.  On March 13, 1989, a geomagnetic storm caused by a coronal mass ejection damaged transformers in the province of Quebec, Canada, leaving six million people without power for nine hours.  In December of 2005, radiation from a solar flare temporarily disrupted satellite communication and GPS navigation signals worldwide, causing nervous moments for pilots attempting to land jet aircraft on fog-shrouded runways.

Because solar flares can generate electrically charged atoms in Earth's upper atmosphere, scientists can estimate the strength of past magnetic storms by measure concentrations of these atoms that fall to Earth and become locked in glacial ice.  An ice core retrieved from Greenland in 1992 revealed that the 1859 storm that Carrington observed was the most powerful to have hit Earth in the past five hundred years.

The solar flare of 1859 has come to be known as "the Carrington event," and scientists are on the alert for another one.  Because such massive flares pose a threat to the 21st century's infrastructure of Internet-linked computers and electrical grids, Carrington's name has recently become synonymous with disaster in alarmist articles in the popular press.

Taking the threat seriously, NASA continuously monitors the sun to provide early warnings of solar flares.  If another "Carrington event" occurs in the near future, technicians around the globe will race to shut down vulnerable electrical systems, and to prepare for damage to satellite-based communication systems.