plasmasphere

American  

[plaz-muh-sfeer] / ˈplæz məˌsfɪər /

noun

Astronomy.

1. a region of cool plasma surrounding the earth, extending 8000–25,000 miles (13,000–40,000 km) into space, and bounded by the plasmapause.

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Etymology

Origin of plasmasphere

First recorded in 1965–70; plasma + -sphere

Example Sentences

Within just nine hours, the plasmasphere was compressed to roughly one-fifth of its usual size.

From Science Daily • Nov. 23, 2025

This marked the first time scientists had continuous, direct data showing the plasmasphere contracting to such a low altitude during a superstorm.

From Science Daily • Nov. 23, 2025

As the storm weakened, the plasmasphere began to replenish with particles supplied by the ionosphere.

From Science Daily • Nov. 23, 2025

These results provide a clearer understanding of how the plasmasphere changes during a severe solar storm and how energy moves through this region of space.

From Science Daily • Nov. 23, 2025

And, since there was no ozonosphere to block out the UV radiation from the primary, the thickness of the ionosphere beneath the plasmasphere was greater.

From Unwise Child by Garrett, Randall