Solar polar regions are vital in controlling solar activities and driving space weather. Despite numerous efforts to explore these regions, to date no imaging observations of the Sun’s poles have been achieved from vantage points out of the ecliptic plane, leaving us uncertainties about their behavior and evolution in sufficient detail. This observation gap gives rise to unanswered three top-level scientific questions, 1) How does the solar dynamo work and drive the solar magnetic cycle? 2) What generates and accelerates the fast solar wind? 3) How do the space weather processes globally originate and propagate throughout the solar system? The Solar Polar-orbit Observatory (SPO) mission, a solar polar exploration spacecraft, is proposed to address these three unanswered scientific questions by imaging the Sun’s poles from large heliolatitudes. In order to achieve its scientific goals, SPO will carry six remote-sensing and four in-situ instruments to measure the vector magnetic fields and Doppler velocity fields in the photosphere, to observed the Sun in the extreme ultraviolet, X-ray, and radio wave bands, to image the corona and the heliosphere up to 45 R⊙, and to conduct in-situ detection of magnetic fields, and low- and high-energy particles in the solar wind. The SPO mission is capable of 1) providing critical vector magnetic fields and Doppler velocities of the polar regions to deepen our understanding of the origin of the solar magnetic cycle, 2) providing unprecedented imaging observations of the solar poles alongside in-situ measurements of charged particles and magnetic fields from high heliolatitudes to unveil the generation and the acceleration of the fast solar wind, and 3) providing observational constraints to improve our ability to model and predict the three-dimensional (3D) structures and propagations of space weather events.
DownLoad: