New Horizons watches the solar wind as it slows down

Where does the solar system end and interstellar space begin?

That's a question scientists have been working to answer using spacecraft traveling beyond the sun's influence.

A team of researchers from the Southwest Research Institute, led by Heather Elliott, is using the Solar Wind Around Pluto (SWAP) instrument aboard New Horizons to track the solar wind in the outer reaches of the solar system. ...