so big that it remained hidden in plain sight for millennia

Perspective matters. If not, tell the first to observe the megastructure we know as Eye of the Sahara (or African Eye), although its name is the Richat Structure. This imposing geological formation is so large that we were not able to observe and study it. until the space age.

In 1965, astronauts on the Gemini 4 space mission photographed the “Eye” while They were looking for circular structures that could have been caused by meteorite impacts. But what was this strange structure? Was it really a meteorite crater? Evidence of the arrival of extraterrestrials? Or something even more mysterious?

In September, intense rains flooded the Sahara. We have new images of the "Resurrection" of its lakes

Some geologists have tried to unravel the secrets of the “Eye of the Sahara”. We know thanks to this that It was formed 542 million years agoin the late Proterozoic period. Long before the first animals came out of the sea.

Or at least that is the dominant theory, because the debate over the origin of this enigmatic (and enormous) structure still continues.