Earlier quoted context omitted.
Their website pitches it as 16 square km
Makes me wonder about building a 16km square datacenter on earth. I wonder if building in that way, with a lower "data density" would allow for more passive cooling and you'd have the large solar field. Wonder if that would be less impactful than how ever many rockets they'll need to send up, plus you could, ya know, ~drive~ bike to a failed machine.
So, it's the solar/cooling panels that make up that space, not the data centre per se.