How to Use protoplanet in a Sentence
protoplanet
noun-
That's because astronomers think swarms of protoplanets — balls of gas, dust, and rock about the size of Mercury or Mars — once swirled around our young sun.
—National Geographic, 17 Apr. 2018
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Scientific consensus about how the moon formed is that billions of years ago, a protoplanet crashed into Earth and the pieces of it revolved around the Earth to form the moon.
—Kristen Rogers, CNN, 22 Nov. 2019
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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, 14 Aug. 2019
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This artist's concept shows the heavy metal asteroid Psyche, which is thought the be a piece of an ancient protoplanet's core.
—Jake Parks, Discover Magazine, 5 Apr. 2019
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Astronomers think Ceres is a protoplanet, the fossilized remains of a world that never fully formed.
—Eric Betz, Discover Magazine, 10 Aug. 2020
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Scientists have long agreed that the Moon formed when a protoplanet, called Theia, struck Earth in its infancy some 4.5 billion years ago.
—Paul Voosen, Science | AAAS, 23 Mar. 2021
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It is thought to be a fragment of an igneous crust of a primitive protoplanet from the early solar system.
—Eva Botkin-Kowacki, Popular Science, 22 Jan. 2023
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Ceres is a protoplanet—a body that seems to be slowly developing into a planet.
—Erin Blakemore, Smithsonian, 17 Feb. 2017
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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, 18 Apr. 2018
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Such an event would have seen Jupiter absorb the protoplanet, which would have been 10 times Earth’s mass, causing their two dense cores to combine and diffuse after only 10 hours, as seen in the simulation above.
—Paul Voosen, Science | AAAS, 14 Aug. 2019
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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, 2 July 2018
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Such a dry, large protoplanet would have separated into layers with an iron-depleted core and an iron-rich mantle, Desch says, some 2% to 3.5% denser than present-day Earth.
—Paul Voosen, Science | AAAS, 23 Mar. 2021
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The diamonds themselves may have been larger until the protoplanet was destroyed.
—John Wenz, Popular Mechanics, 17 Apr. 2018
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The early solar system was little more than a faint protosun surrounded by gas, dust and the odd protoplanet, as in this illustration.
—Douglas Fox, Discover Magazine, 16 May 2017
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For years, Lindy Elkins-Tanton had been looking forward to blasting a probe to the metallic asteroid Psyche, which is orbiting about 230 million miles away and may be the remains of a protoplanet whose surface was smashed to bits eons ago.
—Wired, 29 July 2022
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The idea is that a large protoplanet called Theia bumped into Earth about 4.4 billion years ago, knocking off a moon-sized cloud of debris that eventually coalesced into our favorite satellite.
—Jason Daley, Smithsonian, 11 Jan. 2017
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The idea is that a large protoplanet called Theia bumped into Earth about 4.4 billion years ago, knocking off a moon-sized cloud of debris that eventually coalesced into our favorite satellite.
—Jason Daley, Smithsonian, 11 Jan. 2017
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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, 13 June 2018
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As Sarah Gibbens at National Geographic reports, in the first 10 million years of our planetary family, swarms of protoplanets composed of rock, dust and gas likely pinballed around the sun.
—Jason Daley, Smithsonian, 19 Apr. 2018
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The protoplanet's star is estimated to be a relatively young 2 million years old, the same age at which our now 4.6 billion-year-old solar system saw planet formation.
—Wyatte Grantham-Philips, USA TODAY, 5 Apr. 2022
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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, 2 July 2019
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Though that’s not part of Dawn’s current mission, excitement about the potential for life on the protoplanet could one day fuel future exploration—and a better understanding of what once happened on Earth.
—Erin Blakemore, Smithsonian, 17 Feb. 2017
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Though that’s not part of Dawn’s current mission, excitement about the potential for life on the protoplanet could one day fuel future exploration—and a better understanding of what once happened on Earth.
—Erin Blakemore, Smithsonian, 17 Feb. 2017
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In its violent early years, Earth was a molten hellscape that ejected the moon after a fiery collision with another protoplanet, scientists now suspect.
—Bryn Nelson, CNN, 22 Jan. 2023
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The protoplanet in question may have originated in the outer solar system and migrated inward to the inner solar system.
—John Wenz, Popular Mechanics, 17 Apr. 2018
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Scientists have found the first hard evidence of a large and ancient protoplanet embedded in extraterrestrial diamonds that fell to Earth about 10 years ago.
—Deborah Netburn, latimes.com, 17 Apr. 2018
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Fortunately, the study of protoplanets is just getting started.
—Jay Bennett, Popular Mechanics, 13 June 2018
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In the study, a research team found that the Almahata Sitta meteorite once belonged to a protoplanet, one of tens of early worlds that experienced impacts and buildups to ultimately create the rocky planets in our solar system.
—Doris Elin Salazar, Scientific American, 18 Apr. 2018
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That sharp divide likely comes from the planet formation process, Fulton said: Planets' rocky cores form from smaller pieces, and then the protoplanet's gravity attracts hydrogen and helium gas.
—NBC News, 19 June 2017
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Eventually, some accrete enough mass to form protoplanets.
—Jesse Emspak Space.com Contributor, Fox News, 18 July 2017
Some of these examples are programmatically compiled from various online sources to illustrate current usage of the word 'protoplanet.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
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