As a star ages, more and more of the hydrogen in its core becomes consumed by fusion into helium. Once this core hydrogen is used up, how does the star react and adjust? Stars at this post-main-sequence stage of life actually start to expand, eventually becoming much brighter giant or supergiant stars, shining with a luminosity that can be thousands or even tens of thousands that of their core-H-burning main sequence. We discuss how such stars reach their stellar end points as planetary nebulae or white dwarfs.

To understand ways we might infer stellar distances, we first consider how we intuitively estimate distance in our everyday world, through apparent angular size, and/or using our stereoscopic vision. We explain a practical, quite direct way to infer distances to relatively nearby stars, namely through the method of trigonometric parallax. This leads to the definition of the astronomical unit and parsec, and the concept of solid angles on the sky, measured in steradians or square degrees.

What are the key physical properties we can aspire to know about a star? In this chapter we consider the properties of stars, identifying first what we can directly observe about a given star: position on the sky, apparent brightness, color/spectrum. When these observations are combined with a clear understanding of some basic physical principles, we can infer many of the key physical properties of stars. We also make a brief aside to discuss ways to get our heads around the enormous distances and timescales we encounter in astrophysics.

This section adds details for several past orbiter missions to bring them up to date, and includes the discovery of the Beagle 2 lander apparently intact on the Martian surface.

This section examines planning for missions after Curiosity, including the process of landing site selection. It depicts the activities of NASA’s InSight lander and Perseverance rover, China’s Tianwen-1 lander and Zhurong rover, and orbiting spacecraft including MAVEN, Hope and the Trace Gas Orbiter. Plans for future human exploration of Mars are presented as they were imagined in this period.

A survey of spacecraft results and mission planning for the Martian satellites, Phobos and Deimos, since 2014. Images and other observations by many spacecraft are included, as well as plans for future missions.

We consider solutions that can be obtained via dimensional reduction. We first consider the domain wall, both the perturbative nonrelativistic solution and the exact relativistic solution, first directly in four dimensions, and then show how it can be described via dimensional reduction. Then we consider the cosmic string solution, first directly in four dimensions, and then via dimensional reduction, and finally deriving it at weak field. Finally, we consider the BTZ black hole solution in 2+1 dimensions, deriving it directly, and then show how the BTZ solution and AdS space are continuously related.