Stars and planetary bodies have a special place in our study of the universe. Identifying new planets and stars has a long history in astronomy, and studying their complex surface phenomena continues to be an important scientific endeavor in planetary science and astrophysics. With the advent of modern observational techniques and approaches to data analysis, it is now possible to probe their internal structure at increasingly high resolution and to monitor subtle changes in the deep interiors.
Indeed, having more accurate and detailed information about the stellar and planetary interiors helps us understand the evolution of stars and planetary bodies. Such information is invaluable for studying the links between subsurface structures and surface processes, too. Seismology is therefore central to our quests for understanding their interiors and surfaces. It provides a set of powerful and versatile tools capable of revealing the hidden phenomena inside the Earth, the Moon, and the Sun, amongst other stars, asteroids, planets, and their satellites.
Why extraterrestrial seismology?
In seismic studies, it is critically important to be able to relate any measurable or scientifically significant effects associated with seismic waves to the spatially varying physical properties in the subsurface. Research into the modeling of seismic sources and wave propagation in different stellar and planetary media has allowed scientists to build this foundation for imaging the interiors of stars and planetary bodies. Advances in the acquisition, processing, and modeling of seismic data as a whole have drastically improved the quality of the seismic images and information we have about the subsurface.
Encompassing both the theoretical studies of seismic phenomena and technical applications of seismic imaging developed over the past few decades, seismology is both a pure and an applied science. The pure and applied nature of seismology underpins many major breakthroughs across modern solid-earth planetary, and astrophysical sciences: the discovery of the Earth's and lunar cores, the presence of complex time-dependent differential rotation patterns of the solar interior, and the characterization of the inner radiative cores of red giants, to name but a few.