SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/aero-heliosphere-bubble

What is the heliosphere?

A giant bubble blown by the solar wind around the Sun and planets.

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  1. The Sun's glowing surface layer
  2. A bubble the solar wind inflates around the solar system ✔
  3. The layer of air where planes fly

Why: The Sun constantly blows out a stream of particles called the solar wind. It inflates a huge bubble, the heliosphere, that pushes back the gas between the stars. Interplanetary space lies inside it.

Huh, didn't know that: Near Earth, the solar wind flows out at about 400 kilometers per second.

The dad joke
The Sun blows the biggest bubble in the neighborhood, and it never pops.
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References

Answer: A bubble the solar wind inflates around the solar system. The Sun constantly blows out a stream of particles called the solar wind. It inflates a huge bubble, the heliosphere, that pushes back the gas between the stars. Interplanetary space lies inside it.

  1. NASA Science, Basics of Space Flight, Chapter 1 science.nasa.gov/learn/basics-of-space-flight/chapter1-1
    The solar wind inflates a bubble, called the heliosphere, in the surrounding interstellar medium (ISM).
    Checked 2026-10-10.

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