I found this planet with deep pits and high mountains. So high that just flying my ship across the surface I'll skip back and forth from moving 200 u/s to over 1000 indicating I'm leaving the atmosphere and going into high altitude speeds. Birds fly low enough to clip through the ground. If I pulse engine to it, I can see trees as soon as I arrive. Also, it has storms with gravitational anomalies allowing for unlimited flight (with mid-air recharge) and I got high enough that it drained my environmental shields and life support. I'm pretty sure that means SPACE.

So, it that rare? I actually spent a week trying to re-find this planet. I noticed it's oddity, dropped a save beacon, and went back to my business. Weeks later I went looking for it. I at least knew it wasn't in the first galaxy but I had to go through several systems and many planets, and I can't resist exploring a little, and if I scan all but one animal I have to get the last right? That stretched out the task time. Finally found it. The system with chonky planets seemed familiar so seeing a planet with a save beacon I was optimistic I found it. Surprised to realise I'd found the system 11 months ago. I thought the whole place was a recent discovery, but I guess I just hadn't looked at all the planets back then.