tool for remote sensing of solar system objects, as well as a facility that probes the depths of the cosmos. The same is true of other Astrophysics Division assets, such as the Spitzer Space Telescope, the Chandra X-ray Observatory, the Stratospheric Observatory for Infrared Astronomy, FUSE, the International Ultraviolet Explorer, WISE, IRAS, and others. The James Webb Space Telescope will also make significant contributions to planetary science. Chapter 10 contains details of the contributions that ground- and space-based telescopes make to planetary science.
NASA’s Heliophysics Division
The Heliophysics Division sponsors research in solar and space physics, with a particular emphasis on understanding the Sun and its interactions with Earth and other bodies in the solar system.3 This research also encompasses study of the particle and field environments of other solar system bodies and, in particular, comparative studies of planetary magnetospheres, ionospheres, and upper atmospheres.4 Such studies allow understanding of basic physical processes observed in the geospace environment to be applied to other solar system objects. This capability provides important opportunities to validate understanding of these processes by observing their behavior in multiple planetary settings. Heliophysics activities also benefit planetary science by providing basic data on changes in solar insolation, the solar wind, and the interplanetary magnetic field, which can be connected to changes observed in planetary environments.
Studies of the particle and field environments of planetary bodies have been an integral component of NASA’s planetary missions since the launch of Mariner 2 in 1962. Indeed, the goals of flagship planetary missions such