The strange "knot" that adorns the bright, narrow ribbon of neutral atoms emanating at the boundary between our solar system and interstellar space appears to have been "untied," according to an article published online in the Journal of Geophysical Research .
The researchers believe that the striking ribbon, first shown on maps produced by NASA's IBEX ( Interstellar Boundary Explorer ) probe, forms in response to interactions between interstellar space and the heliosphere. The heliosphere region is of great interest to astronomers because it acts as a protective shield for the solar system , deflecting more than 90% of cosmic rays from outer space.
The sensors on board the IBEX produce global maps of this region every six months. And they have detected very significant variations over time. Analyzes of the first map, released last fall, suggest that the ribbon is somehow directed by the direction of the local interstellar magnetic field outside the heliosphere. In the second map, just released, the polar regions of the lower ribbon and knot screen emissions decrease by up to a third and appear to "untie."
Future missions will benefit from a better understanding of the changes in this space frontier , scientists predict.
