aurora

play

noun au·ro·ra \ ə-ˈrȯr-ə , ȯ- \

Definition of aurora

plural auroras or aurorae play \-(ˌ)ē\

1 :dawn

2 capitalized :the Roman goddess of dawn — compare eos

3 :a luminous phenomenon that consists of streamers or arches of light appearing in the upper atmosphere of a planet's magnetic polar regions and is caused by the emission of light from atoms excited by electrons accelerated along the planet's magnetic field lines

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auroral

play \-əl\ adjective

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aurorean

play \-ē-ən\ adjective

See aurora defined for kids

Examples of aurora in a Sentence

a gorgeous pink aurora aroused us out of our slumber

Recent Examples of aurora from the Web

Most people are amazed by a gorgeous rainbow, a dramatic thunderstorm, or the wonder of the aurora.

— jay ryan, The Atlantic, "The Blue-Collar Eclipse," 11 Aug. 2017
When the Kp index is higher than 7, our area could see some of the aurora.

— nicole blanchard, idahostatesman, "Always wanted to see the Northern Lights? It may be possible in Boise tonight," 16 July 2017
City dwellers might not have great luck seeing the aurora borealis.

— haley hansen, Milwaukee Journal Sentinel, "Northern lights could brighten night sky in Wisconsin on Sunday," 16 July 2017
The aurora forms when those particles flowing from the sun get caught up in the Earth's magnetic field.

— brian manzullo, Detroit Free Press, "Look up! Northern lights may be visible in Michigan tonight," 16 July 2017
The launch tested a new system that helps studies of the ionosphere and aurora.

— jennifer calfas, Time, "NASA Rocket Launch Creates Colorful Clouds Seen Across the East Coast," 29 June 2017
The rocket launch will support deeper studies of the ionosphere — a zone of the Earth's outer atmosphere — and aurora, NASA said.

— CBS News, "NASA launching colorful clouds over the East Coast – here's how to watch," 12 June 2017
Meanwhile, the aurora borealis could be seen as far south as Texas and Florida and — being 1989 — people worried that nuclear war had begun.

— joe kunches, Washington Post, "Trump’s budget eliminates program that detects infrastructure-crippling solar storms," 8 June 2017
When that happens, solar radiation heats the upper atmosphere and charges it with electricity, which is what causes auroras at the northern and southern poles.

— NBC News, "How We'll Safeguard Earth From a Solar Storm Catastrophe," 8 June 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'aurora.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.