P.S. Boros shouldn't have a problem surviving in space. His species is capable of surviving in the amidst of harsh environments from their home world. They do possess the ultimate regenerative ability, while particular Boros himself has the extraordinary self-healing power, physical prowess and latent energy beyond normal conception. It is safe to say he could continue to heal in space without oxygen if necessary.
Oh, but I believe he does have a vaporizing AOE attack, he used on Saitama. I need to check up on it again.
Although, the ship moment brings me to this calculation I found a while back. I'm not sure if it will add much ground. I just wanted to share it due to the whole melting/vaporizing mention earlier.
I can't recall the episode or chapter at the moment but Genos, a Cyborg with enhanced analytical/computational/sensory equipment, gives us a width of 9.23 km and a length of 15.024 km in one of his many notebooks he keeps on Saitama's strength.
Looking at a top down view of the ship we can start to make out areas shown during the Meteoric Burst fight. Specifically these 2 staggered bridges in between the enormous spires. Each one is approximately 800 - 1000m in length (red highlighted areas).
Green line is approx 9230 meters.
1. Judging by the placement of the spire in this shot, I am willing to bet its the rear bridge section in this scene instead of the bottom most one.
The elevated portion is about 800 - 1,000 meters in length.
2. So how much material is melted during this fly through? Well about 60 - 100m is instantly melted during the first frame, well to be more specific, instantly melted in less than one frame.
3. Some dozen or more frames later a shock front of air peel hundreds/thousands of tons of alien metal off the subframe of the ship, I would assume they are affixed to that frame with more than glue or tape so I can't imagine that would be easily accomplished.
Some of these metal panels are over a dozen meters thick, over 100 meters in length/height. 4. And then this happens, and everything in that scene, probably over a 1300x1300 meter area, turned into liquid and blasted backwards.
The heat that accomplished this will likely be in the nuclear/stellar ranges.