Mission Science


The heliosphere – our home in the galaxy – is the region of space surrounding our solar system and dominated by the Sun’s presence. It is formed by the million mile-per-hour solar wind, which blows outward from the Sun all directions in space, inflating a bubble in the local interstellar medium of the galaxy. The heliosphere also shields out the vast majority of galactic cosmic radiation, which bathes the solar system, and imperils astronauts venturing beyond low-Earth orbit.

The Interstellar Mapping and Acceleration Probe (IMAP) is a revolutionary mission that simultaneously investigates two of the most important overarching issues in heliophysics—the acceleration of material expelled from the Sun and interaction of this material with the local interstellar medium. While seemingly disparate, these two are intimately and inseparably coupled because particles accelerated in the inner heliosphere play critical, and so far, only marginally observed, roles in the outer heliospheric interaction. Additional information about the science objectives can be found in the Open Access IMAP Paper.

L1 Science
The instrument suite on IMAP is ideally suited for comprehensive L1 science and real-A measure of the flow of events. A 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. observations. These include solar wind An atom that has become electrically charged by the gain or loss of one or more electrons., heavy ion and A negatively charged elementary particle that normally resides outside (but is bound to) the nucleus of an atom. instruments, time-resolved suprathermal ions and compositionally resolved pickup ions, solar energetic particle instruments, and A device to measure the strength of a magnetic field. measurements.

IMAP solves the inseparable problems of the heliosphere’s interactions with the interstellar medium and the physical origin of particle acceleration of suprathermal particles. The interactions between the heliosphere and the interstellar medium encompass the physical processes, structure, dynamics, energetic particle acceleration, and charged particle propagation associated with the complex interactions between the solar wind and local interstellar medium 

IMAP provides the first comprehensive observations to holistically study these interactions, including complete in situ observations at 1 AU and comprehensive remote global observations to discover the fundamental physical processes that control our solar system’s evolving space environment. IMAP precisely determines the properties of the local interstellar medium and sources and acceleration of suprathermal populations using global observations that are both sufficiently resolved in angle and energy, and over a large enough spectral range to cover all key particle populations. Driven by these new observations, we test hypotheses through detailed and integrated modeling of our 3D evolving heliosphere from inside 1 AU out to the local galactic environs.