Our heliosphere is a vast bubble of plasma – a gas of charged particles – that spews out of the Sun.

This outflow of plasma from the Sun is known as the solar wind. The bubble surrounds the Sun and stretches beyond the planets. Both Voyager spacecraft had to travel more than 11 billion miles (17 billion kilometers) from the Sun in order to cross the edge of the heliosphere. This bubble is moving through interstellar space as the Sun orbits the center of the Milky Way galaxy. As our heliosphere plows through space, it creates a bow wave, like the wave formed by the bow of a ship.

This illustration shows the position of NASA's Voyager 1 and Voyager 2 probes, outside of the heliosphere.

Topics: heliosphere, interstellar space, magnetic fields, plasma, solar wind, space weather

NGSS: PS2, ESS1, ESS2

Image Credits: NASA/JPL-Caltech

Framework for Heliophysics Education

Big Idea 2.2

Illustrated view of the wake our solar system makes in space.

Have leaners investigate this heliophysics big idea with the guiding questions below.

  • Sun, 335 angstrom UV

    Introductory Learner (K-5)

    What is the heliosphere?

  • yellow image of the Sun

    Intermediate Learner (6-8)

    How does the Sun create space weather on Earth?

  • An image of the Sun shows a bright flash in the bottom right side where a solar flare erupts.

    Advanced Learner (9-12+)

    What is the difference between the space around the Sun (the heliosphere) and the interstellar medium (the space between stars?)

Framework for heliophysics education

Heliophysics Resource Database

Use the guiding questions above to explore resources at each level or go directly to our database to search for resources by level, NGSS performance expectation, topic, and mission.

Resource Database
In this animated GIF, a small portion of the Sun appears green. A bright white flash suddenly appears on the edge of the Sun.
On Nov. 4, 2003, this solar flare saturated the X-ray detectors on several Sun-observing spacecraft.
NASA/ESA/SOHO