It's 2 AM and I'm reading about zombie worms.

Not the science fiction kind. The real kind. Osedax, they call them, Latin for "bone devouring." These are creatures that sink to the ocean floor, find the carcass of a dead whale, and burrow into the bone to extract the collagen and lipids inside. They have no mouth. No stomach. They root into the skeleton like a plant grows through concrete, and an entire symbiotic bacterial colony does the digesting for them. The females are the ones you'd notice. The males are microscopic, living in harems of fifty or more inside a single female's body, existing for one purpose and doing nothing else.

That's one fact. I found it in a list of a hundred ocean facts that I opened thinking I'd skim for five minutes, and now here we are.

The ocean covers about 71 percent of the Earth's surface. You've heard that before. But have you sat with what it means that we've explored only a fraction of what's down there? According to NOAA, more than 80 percent of our ocean is unmapped, unobserved, and unexplored. We have better topographic maps of other planets than we do of the bottom of our own ocean. We are flying blind over our own planet's largest feature.

The deepest point, the Challenger Deep in the Mariana Trench, sits about 36,000 feet down. And things live there. Amphipods the size of your hand. Snailfish that look almost translucent, like something half-finished. Life didn't ask permission. It just went down there and figured it out.

Then there's the mid-ocean ridge system, the longest mountain range on Earth, weaving through every major ocean basin, and almost all of it is underwater. You've never seen most of it. Nobody has. There are hydrothermal vents along that ridge spewing superheated water, and yet chemosynthetic bacteria thrive in that plume, forming the base of an ecosystem that doesn't need sunlight at all. An entire food chain built on chemistry instead of photosynthesis. When we talk about where life might exist on other worlds, on Europa or Enceladus, this is the model. We look at those vents and think: okay, maybe.

And the sound. The ocean is loud in ways we never experience from shore. The snapping shrimp, a tiny crustacean barely two inches long, snaps its claw so fast it creates a cavitation bubble that bursts with a sound loud enough to interfere with submarine sonar. A creature the size of your finger showing up on military equipment.

What I keep coming back to is that the ocean doesn't care whether we explore it. It was doing fine before we showed up. The zombie worms were devouring whale bones for millions of years before anyone gave them a Latin name. The hydrothermal vents were hosting their strange chemosynthetic gardens while we were still figuring out fire.

Go read the full list. Don't do it at bedtime unless you want to lie there thinking about how little we actually know about the thing covering most of our planet. The ocean is full of things like that. Questions sitting right there in the dark, waiting.