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
![hydrogen wall illustration](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2018/08/080718_LG_hydrogen-wall_feat_.jpg?fit=860%2C460&ssl=1)
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