Different Planets

How much that happens in Poul Anderson's works hangs on the physical details of different planetary environments? It is completely inadequate for an sf writer to state that the galaxy is full of Earth-like planets where his human characters, having emerged from a spaceship, can walk on grass between trees, breathe the air, eat the food without any dietary supplements etc. Look at the differences between Starkad, Ramnu, Imhotep, Daedalus, Diomedes, Aeneas, Dido, Nike and many others. Some Andersonian planets, like Hermes, Dennitza and Avalon, do come across as conventionally Earth-like but most don't. Falkayn, born on Hermes, settles on Avalon. Flandry, born on Terra, would have settled on Dennitza if...

The Terran Empire, harking back to the Roman Empire, adopts the Latin name for Earth, "Terra," whereas characters in the later stories set after the Empire use the phrase, "Old Earth" - and question whether that planet still exists. Anderson could have written another story to answer that question and how much would the Terrestrial environment have changed after all that time? I like to imagine something rural with hidden high tech. (A Larry Niven character returns to the Solar System after a sub-light-speed trip to the galactic centre and has trouble finding Earth, eventually locating it in orbit around Jupiter. Given enough time, technology might make big differences.)