heliosphere

noun

he·​li·​o·​sphere ˈhē-lē-ə-ˌsfir How to pronounce heliosphere (audio) -ō- How to pronounce heliosphere (audio)
: the region in space influenced by the sun or solar wind
heliospheric
ˌhē-lē-ə-ˈsfir-ik How to pronounce heliosphere (audio)
-ˈsfer-
-lē-ō-
adjective

Examples of heliosphere in a Sentence

Recent Examples on the Web
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.
The hope is that learning the intricacies of the solar wind can help scientists lay out the link between the sun's corona and what's known as the heliosphere. Monisha Ravisetti, Space.com, 14 Aug. 2025 The spacecraft is currently beyond the heliosphere, the sun’s bubble of magnetic fields and particles that extends well beyond the orbit of Pluto. Ashley Strickland, CNN Money, 14 May 2025 Scientific American senior news reporter Meghan Bartels follows two beloved spacecraft, Voyagers 1 and 2, on their epic tour past the outer planets, across the edge of the sun’s influence (the heliosphere) and into interstellar space. Jeanna Bryner, Scientific American, 18 Mar. 2025 The Voyager team used data from the instrument to determine exactly when and where Voyager 1 exited the heliosphere and entered interstellar space. Ashley Strickland, CNN, 5 Mar. 2025 See All Example Sentences for heliosphere

Word History

Etymology

helio- + -sphere

First Known Use

1967, in the meaning defined above

Time Traveler
The first known use of heliosphere was in 1967

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Cite this Entry

“Heliosphere.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/heliosphere. Accessed 13 Sep. 2025.

Kids Definition

heliosphere

noun
he·​li·​o·​sphere ˈhē-lē-ə-ˌsfir How to pronounce heliosphere (audio) -ō- How to pronounce heliosphere (audio)
: the region of space that is affected by the sun or solar wind

More from Merriam-Webster on heliosphere

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