fighting off alien armadas or just waiting to see where he's needed most. This forces us to ask - can Superman breathe in space?
Created in 1938's Action Comics #1, Superman has a pretty well-defined set of powers in modern DC, but there have been times when he's been a lot stranger. The Silver Age Superman had the ability to perform "super-ventriloquism" and produce tiny versions of himself, so it's possible he had a power that let him breathe in space, right? Actually, no, and for one very simple reason.
Superman spends a surprising amount of time in space, whether on his own or in the Justice League's off-Earth base. The Watchtower was up in space where Superman could live rent free, but even he needed a hermetically sealed environment. It’s been shown in comics that Superman can survive in the vacuum of space for a long time, but he can't breathe there. How do we know? Because there's no air to breathe. To breathe in space, Superman would have to take his own air supply off Earth, in which case he'd be as able as anyone else.
When he traverses space, Superman does so by inhaling deeply (think Yoga breathing techniques but on the scale of a guy who can lift planets) and holding his breath while out among the stars. Thankfully, Superman's difficult-to-quantify strength applies to his ability to hold his breath, so there's no clear upper limit, especially given that he's immune to the harsh conditions and constantly being refreshed by solar energy.
Though Superman has fought plenty of battles in the outer atmosphere and been just fine, in some instances he has worn a space suit, such as in the DC Animated Universe. The space suit may not be essential for his immediate survival, but it shows that holding his breath is at least inconvenient enough that he'd rather wear a spacesuit on some occasions. So, no, Superman can't breathe in space, because the term is meaningless in the conditions being described, but he can survive for a long, long time without taking a breath. Couple that with durability, super speed, and flight, and Clark Kent rarely has to worry about running out of breath.
