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 process that forms these particles, found wherever there is plasma, or charged gas, in space, also occurs throughout the heliosphere and along its boundary. — Ashley Strickland, CNN Money, 24 Sep. 2025 This X-ray glow is radiated when the heavy ions of the solar wind, like carbon and oxygen, grab an electron from neutral atoms in either our outer atmosphere or the heliosphere. — Robert Lea, Space.com, 24 Apr. 2026 To this day, the probes are the only spacecraft in history to operate outside of the heliosphere – the protective bubble of particles and magnetic fields generated by the sun. — Eric Lagatta, USA Today, 21 Apr. 2026 Everything within the solar wind is inside the Sun’s extended atmosphere, known as the heliosphere, which means that, in a sense, Earth orbits through the Sun itself. — Literary Hub, 27 Oct. 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

Rhymes for heliosphere

See All Rhymes for heliosphere

Browse Nearby Words

helioseismology
heliosphere
heliostat
See all Nearby Words

Cite this Entry

“Heliosphere.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/heliosphere. Accessed 7 Jul. 2026.

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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

Britannica.com: Encyclopedia article about heliosphere

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