aurora borealis

[ bawr-ee-al-is, -ey-lis, bohr- ]
/ ˌbɔr iˈæl ɪs, -ˈeɪ lɪs, ˌboʊr- /
Save This Word!
See synonyms for: aurora borealis / aurora borealises on Thesaurus.com

noun Meteorology.
the aurora of the Northern Hemisphere.
Test how much you really know about regular and irregular plural nouns with this quiz.
Question 1 of 9
Which of the following nouns has an irregular plural form?
Also called northern lights, aurora polaris.

Origin of aurora borealis

1621; <New Latin: northern aurora; see boreal

Words nearby aurora borealis

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does aurora borealis mean?

The aurora borealis is the shimmering display of lights that sometimes appears in Earth’s Northern Hemisphere. The phenomenon is also commonly called the northern lights.

An aurora is a natural light display in the sky that is caused by particles from the sun interacting with Earth’s magnetic field. Auroras are not exclusive to Earth and occur on every planet in our solar system except Mercury.

The aurora borealis appears in many colors ranging from green and pink to red, yellow, and blue. The word borealis is Latin for boreal, which simply means “northern.”

The aurora borealis is not the only aurora on Earth. The aurora in the Southern Hemisphere is called aurora australis or the southern lights. Both the northern and southern versions can be called aurora polaris because they occur around Earth’s poles, but this term is not commonly used.

The aurora borealis dazzles the many people who travel to see the natural light show, which is considered one of Earth’s most magical phenomena.

Why is aurora borealis important?

If you happen to find yourself way up north, you might get the chance to see a natural light display that puts any fireworks to shame. This light show is called the aurora borealis and humans have been amazed by it for thousands of years. Recorded sightings date back to the ancient Babylonians and Assyrians, and the phenomenon may even be depicted in some ancient cave paintings. The name aurora borealis came much later—it is thought to have been coined by Italian astronomer Galileo Galilei in the 1600s. The lights are named after Aurora, the Roman goddess of the dawn. The word borealis means “northern.”

The aurora borealis is a kind of aurora, a natural light display that occurs in the skies close to Earth’s north and south poles. The process that results in an aurora starts at the sun. Because it is both very hot and very magnetic, the sun frequently releases charged particles (such as protons and electrons) into space that zip toward the planets, including Earth. Earth is surrounded by an invisible magnetic field that protects it (and us) from this solar wind by bouncing it back into space. However, the magnetic field is weakest at Earth’s north and south poles, and some solar particles manage to enter Earth’s atmosphere close to these areas and collide with Earth’s gas particles (oxygen, nitrogen, etc). These collisions emit light that the human eye can see and this, finally, results in an aurora. The aurora borealis is the northern aurora, and the southern aurora is called the aurora australis (australis is Latin for “southern,” and, yes, Australia’s name is based on this word).

While the aurora borealis technically appears throughout the year, the human eye isn’t always able to see it. The visibility of the aurora borealis depends on multiple factors such as your location, the weather, and the time of the year. Organizations such as NASA and NOAA that have studied the aurora borealis provide information for “aurora hunters”—people seeking to observe the lights. The aurora borealis is easiest to see during winter in cold, northern places such as Canada, Scandinavia, Greenland, Russia, and the North Pole itself, though it is sometimes visible at locations farther south.

Did you know ... ?

Like many celestial phenomena, the aurora borealis has been seen as an omen or sign of the gods by many different cultures. For example, a bright red aurora borealis was said to have been visible in the skies prior to the death of Julius Caesar as well as the outbreaks of the American Civil War and the French Revolution. This rare “bloody” version of the northern lights was thought to signal incoming bloodshed or violence.

What are real-life examples of aurora borealis?

The aurora borealis is a spectacular display that can appear in many different colors. Some people travel just to see it.

Getty. The aurora borealis as seen in Alaska.


Quiz yourself!

In which hemisphere does the aurora borealis appear? 

A. Southern
B. Northern
C. Eastern
D. Western

How to use aurora borealis in a sentence

British Dictionary definitions for aurora borealis

aurora borealis
/ (ˌbɔːrɪˈeɪlɪs) /

(sometimes capital) the aurora seen around the North PoleAlso called: northern lights

Word Origin for aurora borealis

C17: New Latin: northern aurora
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Cultural definitions for aurora borealis

aurora borealis
[ (uh-rawr-uh bawr-ee-al-is) ]

A display of colored lights in the sky, also called northern lights, caused by the interaction of particles from the sun with the upper atmosphere near the North Pole. A similar display, called the aurora australis, occurs in the atmosphere above the South Pole.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.