New Horizons may have seen a glow at the solar system’s edge
The ultraviolet signal may mark a wall of hydrogen where the sun’s influence wanes
HELLO FROM THE OTHER SIDE The sun’s journey through the galaxy may build a wall of hydrogen near the edge of the solar system (curved line to the left of this illustration). The New Horizons spacecraft may have seen evidence of just such a wall.
Adler Planetarium/IBEX/NASA