10 Spectacular Solar Storms That Have Shaped Earth's History

The 1859 Carrington Event

Named for Richard Carrington, one of the two astronomers who observed and documented this Aug. 28 - Sept. 2, 1859 solar flare event, the Carrington event is one of the largest space weather events on record.

The "superflare" was associated with two coronal mass ejections (CMEs), the second of which was so severe it triggered a geomagnetic storm that instantly disintegrated 5% of Earth's ozone layer and supercharged the electric currents flowing through the world's telegraph wires, reportedly causing them to spark. Red auroras could also be seen at latitudes as far south as Cuba.

Through reanalysis, scientists estimate its solar flare classification to be between X40 and X50. (The X-class is reserved for the most powerful solar storms.) According to NASA heliophysicist Dr. Alex Young, the event's energy could have powered today's global energy needs for hundreds of thousands of years.

The Auroral Storm of 1582

While analyzing records of ancient auroral events in East Asia, scientists have recently discovered that a severe storm occurred in March 1582. Observers as far equatorward as 28.8 degrees latitude recorded accounts of a great fire in the northern sky.

Today's scientists believe this red aurora may have been caused by a series of CMEs whose Dst values measured in the -580 to -590 nT range. Since few advanced technologies existed back in the 16th century, few to no disruptions would have occurred.

The Great Geomagnetic Storm of May 1921

Between May 13-16, a series of CMEs bombarded Earth's magnetosphere, the strongest of which reached X-class intensity. The New York Times reported that the so-called "sunspot" caused lights on Broadway to dim, and temporarily put the New York Central Railroad out of operation.

May 1967 'Cold War' Solar Flare

On May 23, 1967, during what was the height of the Cold War, a solar storm very nearly changed the course of American history. According to a recent paper in the journal Space Weather, the U.S. government almost ordered an airstrike on the Soviets, whom they believed had jammed U.S. radar and radio communications.

Thankfully, disaster was averted when the Air Force's space weather forecasters (who had only been monitoring space weather since the late-1950s) alerted NORAD in real-time to the solar storm event and its disruptive potential.

August 1972 Solar Flare

Toward the end of the space race, an extreme, X20 solar flare affected the space regions near Earth and the Moon. The flare's ultra-fast storm cloud reached Earth in 14.6 hours flat—the fastest transit time ever recorded. (Ordinarily, the solar wind reaches Earth in two or three days.) Once in Earth's atmosphere, the solar particles interrupted TV signals and even detonated U.S. Navy mines during the Vietnam War.

Although the storm occurred between NASA's Apollo 16 and 17 missions, if a lunar mission had been taking place, its astronauts would have been blasted with a near-fatal dose of radiation.

March 1989 Geomagnetic Storm

On March 10, 1989, a powerful CME erupted on the Sun. By March 13, its resultant geomagnetic storm struck Earth. The event was so intense, the aurora borealis could be seen as far south as Texas and Florida. It also created electric currents underground across much of North America. In Quebec, Canada, six million residents lost power when the solar storm caused a nine-hour blackout of the country's Hydro-Québec power grid.

April 2001 Solar Flare & CME

On April 2, 2001, a massive solar flare explosion near the Sun's northwest region hurled a 7.2 million km per hour coronal mass ejection into space. At that time, it was the biggest X-ray solar flare on record, ranking as an X20 or slightly higher on NASA's solar eruptions scale. The fact that the flare wasn't Earth-directed was a saving grace.

2003 Halloween Solar Storms

On Oct. 28, 2003, the Sun opted to trick (rather than treat) us Terrans by brewing up a solar flare so frightening, it overloaded the sensors measuring it. Before cutting out, these sensors recorded the event as a class X28. However, during later reanalysis, the flare was estimated to have been a X45—one of the most powerful flares on record next to the Carrington event.

The Solar Superstorm of July 2012

Solar storms are constantly occurring, but only those directed at Earth impact our planet; the others simply pass us by. This was the case when a powerful CME, thought to be a Carrington-class storm, crossed Earth's orbital path on July 23, 2012.

Scientists estimate that if the eruption had occurred just one week earlier, Earth would have indeed been in the line of fire. (Instead, the storm struck NASA's Solar Terrestrial Relations Observatory satellite.) According to NASA, had the solar superstorm hit us, it could have caused over $2 trillion dollars worth of damage—or 20 times that wreaked by Hurricane Katrina.

September 2017 Solar Storm

On Sept. 6, 2017, a large X9.3 X-class solar flare erupted on the Sun, becoming the strongest flare of solar cycle 24 (2008-2019). Its geomagnetic storm triggered a category R3 (strong) radio blackout, and NOAA later reported that high-frequency radio used by aviation, maritime, ham radio, and other emergency bands was unavailable for up to eight hours that day—the same day that a Category 5 Hurricane Irma was passing through the Caribbean.