inner planet


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

The standard model is humanity's own system: The inner planets are rocky and solid, outer planets are gaseous. David Grossman, Popular Mechanics, "Mysterious Iron Exoplanet Could Reveal the Secrets of Our Own Solar System," 5 Feb. 2019 The star's inner planets have orbits that resemble Jupiter's Galilean moons. Jay Bennett, Popular Mechanics, "Seven Earth-Like Planets Orbit One Nearby Star," 22 Feb. 2017 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 The inner dots represent the inner planets, while the orange dot represents Jupiter. David Grossman, Popular Mechanics, "Inside NASA's Wildly Complex Plan to Navigate Jupiter's Asteroid Fields," 21 Dec. 2018 BepiColombo will also be using the inner planets for help. Loren Grush, The Verge, "Two spacecraft are embarking on a seven-year journey to decode Mercury’s mysteries," 19 Oct. 2018 Mercury remains our solar system's least studied inner planet, with only NASA's Mariner 10 and MESSENGER probes getting prior looks. David Grossman, Popular Mechanics, "The BepiColombo Probe Is About to Being a 7-Year Mission to Mercury," 19 Oct. 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 Accordingly, unlike the inner planets that move quickly and govern daily activities, Uranus defines major periods of life with its prolonged revolutions. Aliza Kelly Faragher, Allure, "What May's Gemini Horoscope Means for You," 26 Apr. 2018

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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Last Updated

23 Feb 2019

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The first known use of inner planet was in 1951

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