Mirkheim and Ramnu, I considered posting about Diomedes. However, this planet's peculiarities are summarized here and indeed there is more information about Mirkheim here and also about Ramnu here.
The idea was to summarize dramatic natural events that do not involve intelligence. For example, in Poul Anderson, Genesis (New York, 2001), Part One, IX, pp. 96-97:
"Sol swung onward through its orbit, around galactic centre in almost two million years..." (p. 96)
That is dramatic enough. However, at this stage, Anderson postulates neither merely natural processes nor intelligent organisms with familiar motivations but, instead, powerful post-organic intelligences interacting with cosmic processes in ways that had been beyond the scope of their organic predecessors.
Thus, the intelligence on Earth:
protects Terrestrial life by deflecting asteroids and comets;
counteracts harmful effects of cosmic clouds;
directs machines to construct from interplanetary matter discs to shield Earth from lethal radiation generated by nearby supernovae, gamma ray bursters or colliding neutron stars;
over a total of four million years, prepares for the close passage of another star, then deals with the consequences;
manages or mitigates Terrestrial quakes, eruptions, climate swings and crustal plate collisions but then decides to let these processes proceed and observe how life adapts;
addresses other threats never imagined by human beings;
is not primarily concerned with any planet.
Meanwhile, post-organic consciousness spreads between the stars, evolves itself and transcends its earlier stages while the stars also evolve although we are not told how. Thus, intelligence is present but recognizable characters conversing and socially interacting are definitely not.