Select Text Level:

On August 28, 1859, astronomers and everyday citizens observed the first impacts of the largest geomagnetic storm ever recorded. The Great Geomagnetic Storm lasted until early September.
 
A geomagnetic storm is caused by the solar wind interacting with the Earth’s magnetic field. (In fact, a geomagnetic storm is also called a solar storm.) The solar wind is a powerful flow of charged particles (electrons and protons) flowing from instances of solar activity all the way to the edge of the solar system. Solar activities that cause a pulse in the solar wind include sunspots and coronal mass ejections. Usually, pulses from the solar wind take about three days to reach Earth. During the Great Geomagnetic Storm, solar activity was so fierce that particles traveled from the Sun to the Earth in just 18 hours.
 
The most dramatic and beautiful pieces of evidence from geomagnetic storms are the aurora borealis and aurora australis—the Northern and Southern Lights. Usually, the auroras are concentrated in polar regions. During the Great Geomagnetic Storm, however, the Northern Lights were visible as far south as the islands of Cuba and Hawaii, and the Southern Lights were visible as far north as Brisbane, Queensland, Australia.
astronomer
Noun

person who studies space and the universe beyond Earth's atmosphere.

aurora australis
Noun

bright bands of color around the South Pole caused by solar wind and the Earth's magnetic field. Also called the southern lights.

aurora borealis
Noun

bright bands of color around the North Pole caused by solar wind and the Earth's magnetic field. Also called the northern lights.

concentrated
Adjective

items gathered closely together in one place.

coronal mass ejection
Noun

huge burst of solar wind and other charged particles.

electron
Noun

negatively charged subatomic particle.

evidence
Noun

data that can be measured, observed, examined, and analyzed to support a conclusion.

fierce
Adjective

wild or savage.

impact
Noun

meaning or effect.

instance
Noun

an occurrence or example of something.

interact
Verb

to work with or meet.

magnetic field
Noun

area around and affected by a magnet or charged particle.

observe
Verb

to watch.

particle
Noun

small piece of material.

polar
Adjective

having to do with the North and/or South Pole.

proton
Noun

positively charged subatomic particle.

Noun

any area on Earth with one or more common characteristics. Regions are the basic units of geography.

Scandinavia
Noun

region and name for some countries in Northern Europe: Iceland, Norway, Sweden, Finland, and Denmark.

Siberia
Noun

region of land stretching across Russia from the Ural Mountains to the Pacific Ocean.

solar storm
Noun

sudden change in the Earth's magnetosphere, caused by the solar wind interacting with the Earth's magnetic field. Also called a geomagnetic storm.

solar system
Noun

the sun and the planets, asteroids, comets, and other bodies that orbit around it.

solar wind
Noun

flow of charged particles, mainly protons and electrons, from the sun to the edge of the solar system.

sunspot
Noun

dark, cooler area on the surface of the sun that can move, change, and disappear over time.