he·​li·​o·​sphere | \ˈhē-lē-ə-ˌsfir, -ō- \

Definition of heliosphere 

: the region in space influenced by the sun or solar wind

Keep scrolling for more

Other Words from heliosphere

heliospheric \ ˌhē-​lē-​ə-​ˈsfir-​ik , -​ˈsfer-​, -​lē-​ō-​ \ adjective

Examples of heliosphere in a Sentence

Recent Examples on the Web

For the last 11 years, since 2007, Voyager 2 has been traveling towards the outermost layer of what is known as the heliosphere. David Grossman, Popular Mechanics, "Voyager 2 Is Getting Close to Interstellar Space," 5 Oct. 2018 To Schwadron, the project has three key components: to study the global heliosphere, to discover the origins of particle acceleration, and to continue to take key measurements of space weather phenomena. Elise Takahama, BostonGlobe.com, "NASA selects UNH researchers for mission to study safer space travel," 8 June 2018 To some scientists, those readings meant Voyager 1 had left the heliosphere. Sarah Fecht, Popular Mechanics, "NASA: Yes! Voyager 1 Has Reached Interstellar Space," 12 Sep. 2013 But though scientists had measured the speed of the solar wind that forms the heliosphere, the properties of the matter beyond it had never been analyzed. Kim Tingley, New York Times, "The Loyal EngineersSteering NASA’s VoyagerProbes Across the Universe," 3 Aug. 2017 Less solar wind would mean that the heliosphere–a bubble around the solar system maintained by particles emitted from the sun–shrinks significantly. David Grossman, Popular Mechanics, "Changes in the Sun's Activity Could Threaten Earth's Electronics by 2050," 1 Feb. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'heliosphere.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of heliosphere

1967, in the meaning defined above

History and Etymology for heliosphere

helio- + -sphere

Keep scrolling for more

Learn More about heliosphere

Share heliosphere

Statistics for heliosphere

Last Updated

16 Nov 2018

Look-up Popularity

Time Traveler for heliosphere

The first known use of heliosphere was in 1967

See more words from the same year

More from Merriam-Webster on heliosphere

See words that rhyme with heliosphere

Britannica.com: Encyclopedia article about heliosphere

Comments on heliosphere

What made you want to look up heliosphere? Please tell us where you read or heard it (including the quote, if possible).


full of whispering sounds

Get Word of the Day daily email!

Test Your Vocabulary

Difficult Vocab Quiz

  • the-education-of-achilles-eugne-delacroix
  • Which is a synonym of discomfit?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Add Diction

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!