protoplanet
noun
pro·to·plan·et
ˈprō-tō-ˌpla-nət 
: 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
Examples of protoplanet in a Sentence
Recent Examples on the Web
The combination of these unique features allowed scientists to observe the transiting protoplanet.
—
Julia Jacobo, ABC News, 20 Nov. 2024
The most popular theory says that about 4.5 billion years ago, a Mars-size protoplanet slammed into Earth.
—Kenneth Chang, New York Times, 1 Nov. 2023
But scientists have lacked smoking-gun evidence like a crater or pieces of the protoplanet, named Theia.
—Kenneth Chang, New York Times, 1 Nov. 2023
Further afield, one leading theory to account for certain quirks of our solar system’s architecture posits that early shifts in the orbits of Jupiter and Saturn sparked brutal cascades of collisions between nascent protoplanets.
—Lyndie Chiou, Scientific American, 25 Oct. 2023
See all Example Sentences for protoplanet 
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Julia Jacobo, ABC News, 20 Nov. 2024
The most popular theory says that about 4.5 billion years ago, a Mars-size protoplanet slammed into Earth.
—Kenneth Chang, New York Times, 1 Nov. 2023
But scientists have lacked smoking-gun evidence like a crater or pieces of the protoplanet, named Theia.
—Kenneth Chang, New York Times, 1 Nov. 2023
Further afield, one leading theory to account for certain quirks of our solar system’s architecture posits that early shifts in the orbits of Jupiter and Saturn sparked brutal cascades of collisions between nascent protoplanets.
—Lyndie Chiou, Scientific American, 25 Oct. 2023
See all Example Sentences for protoplanet
Dictionary Entries Near protoplanet
Cite this Entry
“Protoplanet.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/protoplanet. Accessed 22 Dec. 2024.
Copy CitationKids Definition
protoplanet
noun
pro·to·plan·et
ˈprōt-ō-ˌplan-ət
: a whirling mass of gas that rotates around a star and is believed to become a planet
Love words? Need even more definitions?
Merriam-Webster unabridged
Share