magnetosphere

noun

mag·​ne·​to·​sphere mag-ˈnē-tə-ˌsfir 

-ˈne-

: a region of space surrounding a celestial object (such as a planet or star) that is dominated by the object's magnetic field so that charged particles are trapped in it

magnetospheric

mag-ˌnē-tə-ˈsfir-ik 

-ˈsfer-, 

-ˌne-

adjective

Examples of magnetosphere in a Sentence

Recent Examples on the Web

If our eyes could see it, Jupiter’s magnetosphere would appear bigger than the full moon in the sky! —Phil Plait, Scientific American, 17 Apr. 2026

The risks are greater when astronauts leave the magnetosphere, a giant invisible magnetic field surrounding the Earth that offers protection against radiation, as in the ARTEMIS II mission. —Tara Haelle, NPR, 12 Apr. 2026

Measuring radiation Unlike astronauts aboard the ISS, the Artemis 2 crew will travel beyond Earth's protective magnetosphere, where exposure to space radiation is significantly higher. —Sharmila Kuthunur, Space.com, 1 Apr. 2026

The study also points to a deeper link between Saturn’s atmosphere and its magnetosphere—the vast region of space shaped by the planet's magnetic field, which could explain why the effect remains stable over long periods. —Maria Azzurra Volpe, MSNBC Newsweek, 30 Mar. 2026

Word History

Etymology

magneto- + -sphere

Note: Term introduced by the Austrian-born physicist Thomas Gold (1920-2004) in "Motions in the Magnetosphere of the Earth," Journal of Geophysical Research, vol. 64, no. 9 (September, 1959), pp. 1219-24.

First Known Use

1959, in the meaning defined above

Rhymes for magnetosphere

• acyclovir
• asthenosphere
• ganciclovir
• atmosphere
• biosphere
• centromere
• chemosphere
• chromosphere
• hemisphere
• hydrosphere
• lithosphere
• mesosphere

Kids Definition

magnetosphere

noun

mag·​ne·​to·​sphere mag-ˈnēt-ə-ˌsfi(ə)r 

-ˈnet-

: a region of space around an object (as a planet or star) that is dominated by the object's magnetic field