How do we (and the Solar System) fit in?

The Solar System is our unique vantage point for exploration of the Universe. The Sun, heliosphere and Solar System bodies – planets, satellites, asteroids and comets – play a critical role in unravelling the secrets of stellar physics, planetary system formation, and fundamental astrophysical processes. We can study our star and its planetary system in exquisite detail, but, this is just a snapshot in time; the Sun’s life stretches across billions of years. To understand the past and future of the Solar System, we must compare it to other stars and their planetary systems. Key issues to be addressed include the followings.

Processes such as magnetic reconnection, plasma heating and acceleration, as well as shocks and turbulence occur throughout the Universe. These phenomena can be studied on all spatial and temporal scales in our own Solar System by remote sensing, and sometimes even in situ. Furthermore, probing the Solar interior by helioseismology is a litmus test for all theoretical models of stellar internal structure and evolution.
The Sun varies on a wide range of spatial and temporal scales, displaying important energetic phenomena across this range. We do not fully understand and cannot accurately predict basic aspects of solar variability.

Variations in Solar activity can affect the terrestrial environment and endangers human activities on various time scales. We need to understand and predict the disturbances of the space environment which are linked to the solar output.

The formation of planets by accretion within a rotating disc is a common phenomenon. The underlying physical processes, including the source of disc viscosity, the protoplanet-disc interaction, and the time scales on which our Solar System as well as exoplanet systems formed, remain largely a mystery.
Space exploration has unveiled an amazing diversity of objects in the Solar System, and we expect a similar variety in the nature of exoplanets. This richness needs to be understood.

Although we still do not know how life appeared on Earth, it must have benefited from the presence of liquid water. Searching for liquid water in the atmospheres of the terrestrial planets and the interiors of outer satellites is a major objective for future planetary exploration.

Therefore, key questions to be addresses are:

• What can the Solar System teach us about astrophysical processes?
• What drives solar variability on all scales?
• What is the impact of solar activity on life on Earth?
• What is the dynamical history of the solar System?
• What can we learn from Solar System exploration about its formation and evolution?
• Where should we look for life in the Solar System?