How does IBEX collect data?
IBEX uses two sensors to collect Energetic Neutral Atoms, or ENAs. ENAs are particles with no charge that move very quickly. ENAs are made from solar wind particles. Solar wind particles are charged, meaning they have lost electrons. Another name for a particle that has lost one or more electrons is an “ion”. Sometimes these solar wind ions interact with neutral atoms that come from the Interstellar Medium, the material between the stars. The solar wind ions take electrons from these neutral atoms and get knocked away. Since the solar wind particles are no longer charged, meaning they have equal numbers of protons and electrons, they no longer react to magnetic fields in the area, and they travel very fast in a straight line from the spot where the interaction occurred. Some of the ENAs happen to get knocked in a straight line in just the right way so that they travel toward the IBEX spacecraft. This is how the scientists can map the boundary – they know exactly where a particle came f
