im·​pac·​tor | \ im-ˈpak-tər How to pronounce impactor (audio) \
variants: or impacter

Definition of impactor

1 : a machine (such as a steam or air hammer or a pile driver) or part that operates by striking blows
2 : meteorite

Examples of impactor in a Sentence

Recent Examples on the Web

Instead, the mass could come from an ancient impactor, the team argues. National Geographic, "Huge mystery blob found under the moon's far side," 11 June 2019 The team found that as much as 30 percent of the water present in the initial impactors was transferred to the post-impact debris when the collisions occurred at speeds and angles that are analogous to asteroids slamming into the planet. Jay Bennett, Popular Mechanics, "NASA's High-Speed Cannon Used to Explore the Origins of Water on Earth," 26 Apr. 2018 With that in mind, the researchers calculated an estimate of the size of the impactor. Scott K. Johnson, Ars Technica, "Huge, previously unknown impact crater found beneath Greenland’s ice," 18 Nov. 2018 So even though the impactor loses its water, some of it is recaptured as the melt rapidly quenches. Jay Bennett, Popular Mechanics, "NASA's High-Speed Cannon Used to Explore the Origins of Water on Earth," 26 Apr. 2018 This goes against previous studies that suggested a much larger impactor. John Wenz, Popular Mechanics, "New Study Explains the Solar System Smash-Up That Created Mars' Two Moons," 18 Apr. 2018 In short-warning scenarios, kinetic impactors like DART would not be enough. NBC News, "Space scientists have big plans to avert an asteroid apocalypse," 6 Apr. 2018 Given enough warning, less complicated options like a kinetic impactor might be preferable. Popular Mechanics, "The Asteroid Hunters," 11 Nov. 2015 The asteroid that wiped out the dinosaurs 65 million years ago measured about 10 kilometers wide, but any impactor larger than 1 kilometer wide could trigger catastrophic climate change. Eoin O'carroll, The Christian Science Monitor, "Buzzworthy space rocks: Asteroid hunters prep for near miss," 10 Oct. 2017

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

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First Known Use of impactor

1872, in the meaning defined at sense 1

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Last Updated

2 Aug 2019

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The first known use of impactor was in 1872

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a usually brief trip or an expedition

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