OK so scientists just found six brand new structures sitting deep inside the Earth, like 2,900 kilometers down where the mantle meets the outer core, and I need everyone to stop what they're doing for a second because we are living on a planet that still has surprise rooms in it.

Here's how they did it. The research team used something called PKP precursor waves, which are basically seismic waves from earthquakes that travel through the planet and arrive a tiny bit early, before the main wave, because they bounced off something weird down there. Scientists can read those early arrivals like a flashlight in a dark basement. And when researchers built a new global map from all that data, six regions lit up that had never been properly sampled before, chunks of deep Earth structure that previous studies basically walked right past.

You can read the full breakdown over at ScienceAlert, which is where I found this and immediately sent it to three group chats.

What gets me is the scale of the ignorance here, and I mean that in the most wonderful way. We have rovers on Mars, we've photographed the dark side of Jupiter, we've caught a black hole shredding a star on camera. And the planet under our actual feet? Still got unexplored architecture. These structures sit at the core-mantle boundary, a zone so deep and so hostile that no instrument will ever visit it. Everything we know about it comes from reading earthquake waves like tea leaves, and the tea leaves just went "oh, you missed a spot" six times.

The new map shows the six new regions and also gives researchers a sharper picture of ones we already knew about, like the giant blob-like zones beneath Africa and the Pacific that have been puzzling geophysicists for decades. Some of those are thought to be ancient ocean floor that got shoved down billions of years ago and is just... hanging out near the core. There's a real chance some of these newly spotted structures are the same kind of thing, fragments of a planet that no longer exists anywhere we can see.

think about that. The floor of an ocean older than almost anything on the surface, preserved in the planet's basement like a box of photos nobody opened.

And yes I have a whole opinion about this, longtime readers know it: we keep racing to catalog the cosmos while the deep Earth, and the deep ocean for that matter, is sitting right here stuffed with alien-seeming territory we've barely mapped. I love the space stuff, I will never stop loving the space stuff. But finding never-before-seen structures by listening to earthquakes rattle through rock beneath Samoa is uniquely funny and humbling in a way I can't quite get over.

The researchers' next job is figuring out what the six regions actually are, whether they're dense sunken slabs, oddly hot patches, or something we haven't got a good name for yet. I'll be following along, because "we found it but we don't know what it is" is my favorite genre of science story, full stop, and the Earth keeps cranking them out without even trying.