Data from the Ulysses spacecraft
show the sun has reduced its output of solar wind to the lowest levels since accurate readings became available.
"The sun's million mile-per-hour solar wind inflates a protective bubble, or heliosphere, around the solar system.
It influences how things work here on Earth and even out at the boundary of our solar system where it meets the galaxy
The solar wind interacts with every planet in our solar system. It also defines the border between our solar system and interstellar space.
This border, called the heliopause, surrounds our solar system where the solar wind's strength is no longer great enough to push back the wind of other stars. The region around the heliopause also acts as a shield for our solar system, warding off a significant portion of the cosmic rays outside the galaxy.
Cosmic rays are linked to engineering decisions for unmanned interplanetary spacecraft and exposure limits for astronauts traveling beyond low-Earth orbit.
clipped from: science.nasa.gov 
