1 protoplanet | Definition of protoplanet

protoplanet

noun
pro·​to·​plan·​et | \ ˈprō-tō-ˌpla-nət How to pronounce protoplanet (audio) \

Definition of protoplanet

: a hypothetical whirling gaseous mass within a giant cloud of gas and dust that rotates around a sun and is believed to give rise to a planet

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Other Words from protoplanet

protoplanetary \ ˌprō-​tō-​ˈpla-​nə-​ˌter-​ē How to pronounce protoplanetary (audio) \ adjective

Examples of protoplanet in a Sentence

Recent Examples on the Web

Because of the immense pull of Jupiter, most of the collisions ended up being head-on, sending the protoplanet directly to the core of Jupiter. John Timmer, Ars Technica, "Jupiter may have had a head-on collision with a massive protoplanet," 14 Aug. 2019 Earth’s moon formed nearly 4.5 billion years ago, in the aftermath of a cataclysmic collision between the proto-Earth and another protoplanet. Simon J. Lock, Scientific American, "When Earth and the Moon Were One," 2 July 2019 The moon probably formed from another protoplanet smashing into the young Earth, and a runaway planet has long been the suspected culprit behind the odd tilt of Uranus. John Wenz, Popular Mechanics, "We Might Finally Know What Smacked Uranus Sideways," 2 July 2018 The discoveries, and the new method used to make them, are a thrilling advancement of exoplanet sciences to include protoplanets still in the process of formation, which were previously hidden from view. Jay Bennett, Popular Mechanics, "Three Newborn Planets Discovered Around an Infant Star," 13 June 2018 Fortunately, the study of protoplanets is just getting started. Jay Bennett, Popular Mechanics, "Three Newborn Planets Discovered Around an Infant Star," 13 June 2018 Therefore, the meteorite diamonds reveal information about their parent protoplanet. Doris Elin Salazar, Scientific American, "Diamonds in Meteorite May Come from a Lost Planet," 18 Apr. 2018 The diamonds themselves may have been larger until the protoplanet was destroyed. John Wenz, Popular Mechanics, "Diamond-Encrusted Meteorite Could Be From a Lost Planet," 17 Apr. 2018 The diamond pieces inside the meteorite hold a compelling record of these protoplanets and their collisions, according to the study. Doris Elin Salazar, Scientific American, "Diamonds in Meteorite May Come from a Lost Planet," 18 Apr. 2018

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

1949, in the meaning defined above

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More from Merriam-Webster on protoplanet

Britannica.com: Encyclopedia article about protoplanet