How Does IBEX study the boundary of the Solar System?
Unlike many satellites in space that collect light, IBEX collects particles. These particles come from the boundary of the Solar System and beyond — from the interstellar mediumAll the gas and dust found between stars.. IBEX has two sensors that collect particles as the satellite orbits the Earth. The satellite spins as it orbits so that over the course of six months, each sensor has the opportunity to collect particles from every part of the sky. As they collect the particles, the sensors and spacecraft keep track of the area the particles came from, the time they entered the sensor, the mass of the particles, and the amount of energy each particle has. This allows the science team to build a map of how many particles of each energy came from each direction in the sky.
By analyzing the map, the team of scientists can determine what the interaction of the solar windA stream of charged particles, mostly protons and electrons, that escapes into the Sun's outer atmosphere at high speeds and streams out into the solar system. and interstellar medium is like in all of the areas of the protective bubble around the Solar System. For example, scientists are trying to find out if there are some areas where the interstellar medium stops the solar wind from flowing outward more quickly (like slamming on the brakes) than other places (where a slow gradual stop may occur.) Also, scientists are trying to determine the overall shape of the bubble which may be affected by differences in densityThe amount of mass or number of particles per unit volume. In cgs units mass density has units of gm cm-3. Number density has units cm-3 (particles per cubic centimeter)., and magnetic fieldsA field of force that is generated by electric currents. The Sun's average large-scale magnetic field, like that of the Earth, exhibits a north and a south pole linked by lines of magnetic force. in the interstellar medium.