Halley's comet

American  

[hal-eez, hey-leez] / ˈhæl iz, ˈheɪ liz /

noun

1. a comet with a period averaging 76 years. In this century it was visible to terrestrial observers just before and after reaching perihelion in 1910 and again in 1986.

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Halley's Comet British  

/ ˈhælɪz /

noun

1. a comet revolving around the sun in a period of about 76 years, last seen in 1985–86

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Halley's comet Scientific  

/ hăl′ēz,hā′lēz /

1. A short-period comet that orbits the Sun once every 76 years. It is visible to the unaided eye and last appeared in 1986, when close observation by spacecraft showed that its nucleus measures about 16 km (10 mi) by 8 km (5 mi) and is composed of water ice, stony minerals, and organic compounds. Its next appearance will be in the year 2061.

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Pronunciation

The common pronunciation for both the comet and the astronomer after whom it is named is . This is the pronunciation usually recommended by astronomers. However, several variant spellings of the name, including Hailey, Haley, and Hawley, were used interchangeably during the astronomer's own time, a period when spellings even of proper names were not yet fixed, and corresponding pronunciations have survived. The pronunciation in particular remains associated with Halley's comet ; it is less likely to be heard as a pronunciation of Edmund Halley .

Etymology

Origin of Halley's comet

Named after Edmund Halley, who first predicted its return

Example Sentences

Now, the NFL’s answer to Halley’s comet is tearing across the sky again.

From The Wall Street Journal • Jan. 13, 2026

The shower originated in debris of Halley's comet, one of the most famous in history.

From BBC • Oct. 20, 2023

It’s 2061 and a solar flare has pushed Halley’s comet onto a collision course with Earth.

From New York Times • Aug. 6, 2021

Jackson’s host allows announcer Don Pardo to pose questions to contestants such as, “When is the next reappearance of Halley’s comet scheduled?” only to cut them off before they answer.

From Salon • Oct. 7, 2019

It didn’t become Halley’s comet until 1758, some sixteen years after his death.

From "A Short History of Nearly Everything" by Bill Bryson