Copyright © National Academy of Sciences. All rights reserved.
Solar and Space Physics: A Science for a Technological Society
REPORT OF THE PANEL ON SOLAR AND HELIOSPHERIC PHYSICS
291
Key isotope ratios (D/H, 3 He/ 4 He, 22 Ne/ 20 Ne) will place strong constraints on big bang cosmology and the
evolution of matter in the galaxy. From high-precision observations of secondary O and He, the strength
and orientation of the local interstellar magnetic field and the structure of the outer heliosheath can be
independently deduced. Extended IBEX observations will provide reconnaissance, and IMAP will have all
the necessary capabilities for decisive measurements. The Voyagers will provide ground truth through and
beyond the heliopause, and theory and modeling will have the challenge of reconciling these observations.
10.4.5 Contributions of the SHP Panel’s Program to Achieving the Decadal Survey’s Key Science Goals
This section summarizes the impact that the SHP panel’s proposed program can have on realizing the
key science goals of this decadal survey (see Chapter 1).
The top section of Table 10.1 illustrates how the space missions and ground-based facilities described
in this chapter will address the SHP panel’s science goals and associated actions outlined in Box 10.1. Note
that implementation of the entire SHP program would make major contributions to all four SHP goals and all
14 SHP actions (for details, see §10.4.1-10.4.4 and descriptions of the individual actions in §10.4.6-10.5).
The bottom section of Table 10.1 illustrates how the SHP panel’s program can help realize decadal
survey key science goals 1-4 during the coming decade and beyond. As has already been noted, several
space missions and ground-based facilities promise to make transformative contributions to decadal survey
key science goal 1 with unique remote-sensing measurements that will discover how the Sun’s magnetic
activity transfers matter and energy from the photosphere through the atmosphere and out into the heliosphere. The exploratory Solar Orbiter and SPP missions, including multiple passes through the solar corona
by SPP, will address decadal survey key science goal 1 by providing the first in situ observations of the
inner heliosphere close to the Sun. These truly transformative observations will reveal new details of solar
and interplanetary processes and greatly improve researchers’ ability to understand, model, and predict
variability in the space environment. The activities also support decadal survey key science goal 2 in that
they will lead to a better understanding of the interplanetary plasma and energetic-particle environments
that impinge on the magnetosphere.
Similarly, IMAP will image temporal and spatial variations of the outer heliosphere with about 80 times
better sensitivity while providing comprehensive measurements of solar wind and energetic-particle inputs
to geospace. Many of the measurements will also reveal details of basic solar and heliospheric processes
that are at work in astrophysical systems throughout the galaxy, fulfilling decadal survey key science goal
3. Finally, the planned observations, spanning a broad array of plasma environments, will permit the study
and understanding of the fundamental physical processes that act within the heliosphere and in astrophysical plasmas throughout the universe (decadal survey key science goal 4).
10.4.6 Goals for the Ongoing Program and Missions in Development
10.4.6.1 Science Goals for Solar Probe Plus
The space age has revolutionized understanding of the Sun and heliosphere, but after more than a
half-century two of the most fundamental questions in heliophysics remain unanswered: Why is the solar
corona so much hotter than the photosphere? How is the solar wind accelerated? Those questions are
critical for understanding our solar system, determining the effects of solar inputs on the dynamic heliosphere, and developing predictive space weather capabilities. Achieving closure requires direct samples
of electromagnetic fields, plasma, and energetic particles in the solar corona and across the Alfvénic
transition between the corona and solar wind. Recognizing the urgency of such observations, the 2003
Solar and Space Physics: A Science for a Technological Society
REPORT OF THE PANEL ON SOLAR AND HELIOSPHERIC PHYSICS
291
Key isotope ratios (D/H, 3 He/ 4 He, 22 Ne/ 20 Ne) will place strong constraints on big bang cosmology and the
evolution of matter in the galaxy. From high-precision observations of secondary O and He, the strength
and orientation of the local interstellar magnetic field and the structure of the outer heliosheath can be
independently deduced. Extended IBEX observations will provide reconnaissance, and IMAP will have all
the necessary capabilities for decisive measurements. The Voyagers will provide ground truth through and
beyond the heliopause, and theory and modeling will have the challenge of reconciling these observations.
10.4.5 Contributions of the SHP Panel’s Program to Achieving the Decadal Survey’s Key Science Goals
This section summarizes the impact that the SHP panel’s proposed program can have on realizing the
key science goals of this decadal survey (see Chapter 1).
The top section of Table 10.1 illustrates how the space missions and ground-based facilities described
in this chapter will address the SHP panel’s science goals and associated actions outlined in Box 10.1. Note
that implementation of the entire SHP program would make major contributions to all four SHP goals and all
14 SHP actions (for details, see §10.4.1-10.4.4 and descriptions of the individual actions in §10.4.6-10.5).
The bottom section of Table 10.1 illustrates how the SHP panel’s program can help realize decadal
survey key science goals 1-4 during the coming decade and beyond. As has already been noted, several
space missions and ground-based facilities promise to make transformative contributions to decadal survey
key science goal 1 with unique remote-sensing measurements that will discover how the Sun’s magnetic
activity transfers matter and energy from the photosphere through the atmosphere and out into the heliosphere. The exploratory Solar Orbiter and SPP missions, including multiple passes through the solar corona
by SPP, will address decadal survey key science goal 1 by providing the first in situ observations of the
inner heliosphere close to the Sun. These truly transformative observations will reveal new details of solar
and interplanetary processes and greatly improve researchers’ ability to understand, model, and predict
variability in the space environment. The activities also support decadal survey key science goal 2 in that
they will lead to a better understanding of the interplanetary plasma and energetic-particle environments
that impinge on the magnetosphere.
Similarly, IMAP will image temporal and spatial variations of the outer heliosphere with about 80 times
better sensitivity while providing comprehensive measurements of solar wind and energetic-particle inputs
to geospace. Many of the measurements will also reveal details of basic solar and heliospheric processes
that are at work in astrophysical systems throughout the galaxy, fulfilling decadal survey key science goal
3. Finally, the planned observations, spanning a broad array of plasma environments, will permit the study
and understanding of the fundamental physical processes that act within the heliosphere and in astrophysical plasmas throughout the universe (decadal survey key science goal 4).
10.4.6 Goals for the Ongoing Program and Missions in Development
10.4.6.1 Science Goals for Solar Probe Plus
The space age has revolutionized understanding of the Sun and heliosphere, but after more than a
half-century two of the most fundamental questions in heliophysics remain unanswered: Why is the solar
corona so much hotter than the photosphere? How is the solar wind accelerated? Those questions are
critical for understanding our solar system, determining the effects of solar inputs on the dynamic heliosphere, and developing predictive space weather capabilities. Achieving closure requires direct samples
of electromagnetic fields, plasma, and energetic particles in the solar corona and across the Alfvénic
transition between the corona and solar wind. Recognizing the urgency of such observations, the 2003