If the planet stands any chance of keeping a secret from prying humans, it's deep in the oceans.

In fact, we've long known there are sprawling ranges — called seamounts — deep underwater, many as breathtakingly grand as anything we've seen on terra firma.

Being in the deepest depths, those clandestine cliffs and nebulous valleys elude not just human eyes, but even sea-probing satellites and sonar-equipped ships.

And that's a good thing. Because when we do occasionally find one of the planet's secrets stashes, it's a trove of scientific data — untarnished geological features and marine habitats that spent millennia oblivious to our presence.

Think of it as an alien planet teeming with life.

You might understand then why a team of Canadian researchers has been staring at screens for the last 16 days or so. They've been remotely exploring newly discovered seamounts, some at least as high as the Rockies, off the coast of British Columbia.

"We were just glued to the screens," Robert Rangeley, team leader and science director for Oceana Canada, told CBC News. "We would dive from 7 in the morning to 7 at night and every turn was different."

To find the ranges, which are capped by an extinct volcano, the team had to go deep — to a place where only robots dared tread.

A robot being prepared for insertion in the ocean The team, a collaboration between government and nonprofit groups, used live-streaming robots to explore the seamounts. (Photo: Northeast Pacific Seamount Expedition Partners)

The original mission was to guide two remotely operated vehicles (ROVS) through the peaks and valleys of two seamounts that were already known.

But over the 1,500-mile journey along the coast they discovered six more seamounts and descended into a spectacular alien landscape, teeming with corals, sponges, sea stars and marine animals — many of them critically endangered, or species never before recorded.

"What we saw underwater was nothing short of awe-inspiring," Rangeley noted in a press release.

Octopus poking out of rock Seamounts are vital habitats for marine life increasingly under siege from commercial fishing. (Photo: Ocean Exploration Trust, Northeast Pacific Seamount Expedition Partners)

"The remotely operated vehicle allowed us to explore thousands of metres into the dark ocean depths," he added. "When we reached a seamount, it was often like we were entering a forest, only of red tree corals and vase-shaped glass sponges."

And those otherworldly forests, which could be thousands of years old, were home to still more secrets.

"These areas were filled with a diversity of other animals including anemones, feather stars, octopuses, lobsters and rockfishes."

In all, researchers collected 150 specimens, many from species that have yet to be identified.

Marine life specimens in glass dishes The team collected many specimens, some from species that have yet to be documented. (Photo: Northeast Pacific Seamount Expedition Partners)

"I wonder how many more of these fragile forests exist in the ocean, in unexplored regions?" Rangeley mused in the release.

But amid all that wonder, scientists caught a sobering sight on their monitors. There, clawed into the side of the one of those mountains, was discarded fishing line.

Yes, we're still on Earth.

Rangeley says these spectacular ranges — vital habitats for marine life that seem to be disappearing everywhere else — need to be protected.

Fishing lines that gouge the ocean floor wreak havoc on seamounts and their unique marine habitats. In fact, researchers note, many commercial vessels seek out seamounts knowing them to be rich refuges for fish.

"It is clear the best way to manage these biodiversity hotspots is to close all Canadian seamounts to bottom contact activities," Rangeley says.

You can catch a hint of the beauty and mystery of sea mounts in the video below.

Researchers discover mesmerizing underwater world teeming with new life
Canadian researchers been remotely exploring newly discovered seamounts, some at least as high as the Rockies, off the coast of British Columbia.