inner planet

noun

Definition of inner planet

: any of the planets Mercury, Venus, Earth, and Mars whose orbits are within the asteroid belt

Examples of inner planet in a Sentence

Recent Examples on the Web Earth, which is protected by a thick, but livable atmosphere enabled by our own internal energy source—the spinning dynamo of our molten iron core—is the only inner planet with adequate protection from the sun. Caroline Delbert, Popular Mechanics, "Elon Musk Says the Sun Can Power All of Civilization. Of Course He's Right.," 16 Oct. 2020 The instability also scattered oddball moons and asteroids and triggered smaller bodies to pummel the inner planets. Paul Voosen, Science | AAAS, "Cataclysmic bashing from giant planets occurred early in our Solar System's history," 21 Jan. 2020 The lunar rocks ultimately tell us of a violent chapter in solar system history, when a period known as the Late Heavy Bombardment rained down space rocks, heavily scarring the inner planets. Korey Haynes, Discover Magazine, "Legacy of Lunar Data: How Apollo Revealed our Moon," 20 May 2019 Many scientists think these holes occurred during a period of the Solar System known as the Late Heavy Bombardment — a period when a huge number of asteroids smacked into the inner planets. Loren Grush, The Verge, "This weekend, China embarks on a historic mission to land on the far side of the Moon," 6 Dec. 2018 Instead, all planetary systems fortunate enough to host a gas giant in their outskirts should automatically have water-rich material falling on their rocky inner planets. Nola Taylor Redd, Smithsonian, "How Jupiter May Have Gifted Early Earth With Water," 20 June 2018 As our solar system formed, the early sun blasted the inner planets with radiation and high-speed plasma, which drove off most of the gases (hydrogen, water vapor and CO2). Scott Denning, Washington Post, "May the 4th be with Earth, a perfect planet that’s not too Hoth or Tatooine," 4 May 2018 Planet Nine’s gravitational influence could even serve as a solution to the long-standing mystery of why the sun’s axis of spin is tilted six degrees askew to the orbits of the inner planets. Lee Billings, Scientific American, "Looking for Planet Nine, Astronomers Gaze into the Abyss," 22 Mar. 2018 The lunar rocks ultimately tell us of a violent chapter in solar system history, when a period known as the Late Heavy Bombardment rained down space rocks, heavily scarring the inner planets. Korey Haynes, Discover Magazine, "Legacy of Lunar Data: How Apollo Revealed our Moon," 20 May 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'inner planet.' 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 inner planet

1951, in the meaning defined above

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The first known use of inner planet was in 1951

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Last Updated

20 Oct 2020

Cite this Entry

“Inner planet.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/inner%20planet. Accessed 21 Oct. 2020.

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