If by squares you mean sector, then one sector would be OK, but the debris field covers 6 sectors, and not just any 6 sectors on the map, no the 6 sectors that just happen to have my base in them.Played with maxed meteor storms, yes, that can clear out the targeted map square and some of the nearby ones, but in those map you need to spread out fast and hard (and hope in the early part and keep enough money for a restock ship)
Someone asked what my sample size is, its small, only my 3rd game, but in all 3 the meteor storms have been orders of magnitude above anything I've seen on the dozens of Youtubes I've watched, on this play through I even selected no mystery, hoping that that was previously the source of these, but its not.