Gomez carries a deadly weapon: his smile. Unlike some of the early explorers of Mars (like Biggs and Parkhill), Gomez seems like a nice guy. When he meets a Martian, Gomez doesn't react in fear or violence—he waves hello, listens, and tries to find common ground (18). And when he says to the Martian that they'll "never agree," he just walks away peacefully rather than, you know, shooting him.
Gomez is also unique because he's the only non-Anglo in the book. We can't be sure, but "Tomás Gomez" sure sounds like a Latino name—and Bradbury mentions his "brown hands" (6). It's something to think about, that the nicest guy in the book is Latino.
If some psycho like Yll met Tomás Gomez (or if some psycho like Biggs had met Muhe Ca), this book's already high body count would probably go up by at least one.
But Muhe Ca is like a Martian version of Gomez: a nice guy (er, Martian) who's willing to talk to people who are different from him. In fact, part of the fun of this story is seeing all the ways Ca and Gomez are similar. For instance, when their hands cannot touch, Gomez shouts "Jesus Christ" and Ca shouts "Name of the gods" (43-4). Bradbury reinforces this connection by talking about Gomez and Ca together, as "they."
So Gomez and Ca may be separated by many years, and they may be different species, but they're not so different after all. Sounds kind of like a sophisticated version of the Barney theme song.
"Pop" is the nickname Gomez gives to the old gas station owner at the beginning of the story. Although he only appears briefly, Pop has a lot to say, mostly about how much he likes Mars because it's different: "We've got to forget Earth and how things were. We've got to look at what we're in here, and how different it is. I get a hell of a lot of fun out of just the weather here. It's Martian weather" (5). (Pop also gets to drop some big foreshadowing bombs, like his statement that "time is crazy up here" ).
Like Spender and Gomez, Pop appreciates Mars because it's different from Earth. In fact, if his station gets too busy, he's planning to move to a less busy road so he can appreciate Mars some more (4). We could even say that he's like Spender, if Spender had been just a little less trigger-happy.