We still don’t know

An immortal jellyfish? 10 spooky and unanswered questions about the sea

Some people are scared of the ocean. Can you blame them? Though waters cover 70% of our planet, scientists are still scratching their heads about certain unanswered questions. How long can blue whales actually live? What substance makes some waters glow eerily white at night? And what’s with the self-rejuvenating, immortal jellyfish? These are some of the mysteries we’ll explore in this article!

Found abandoned in 1872 with sails set, cargo intact, and dinner still on the table, the Mary Celeste is the poster child for maritime enigmas. The whole crew vanished without a trace and was never heard of again.

Mutiny? Rogue wave? Alcohol fumes? Giant squid? No theory fully fits. It's a fascinating tale that has been the subject of documentaries, theatre plays, novels, and movies.

For centuries, sailors have reported seeing entire portions of the ocean surface glowing white at night, like a ghostly reflection.

An explanation could be massive blooms of bioluminescent bacteria, but no one knows how they coordinate light across such huge distances or why the phenomenon lasts for hours. Even with satellite detections, it remains one of the ocean’s eeriest light shows.

Tales of a giant squid have been alive for centuries, but it was only in 2004 that humanity was able to photograph this fabled creature. In that year, a Japanese team captured a live one on camera in its natural habitat and finally proved that the creature behind centuries of sea-monster legends was very real.

And yet, we still know shockingly little about its life cycle, breeding habits, or how something that big stays so well hidden.

You’d think the largest creature ever to exist would be the easiest to study. Nope. We still struggle to track migration patterns, understand their communication system, or explain the full recovery timeline after they were nearly hunted to extinction.

Turritopsis dohrnii cheats death by reverting its adult cells back to a juvenile state when stressed. It’s like if a human under pressure suddenly turned back into a toddler.

This regeneration process is wildly complex and not fully understood, and scientists hope that cracking its secret might reveal insights into aging itself.

The stretch between Florida, Bermuda, and Puerto Rico has inspired endless theories. Unexplained disappearances, bizarre compass behavior, and strange weather patterns have contributed to building the legend.

Scientific explanations abound, from methane hydrates to violent storms, but the Triangle’s mythic aura refuses to die.

The Challenger Deep, the trench’s lowest point, plunges almost 7 miles. Only a handful of people have ever explored its bottom, including filmmaker James Cameron in 2012.

What lives down there? What geological processes unfold under such pressure? Every new expedition reveals creatures that look like they belong in fever dreams.

Off the coast of Japan lies a submerged stone structure with terraces, pillars, and sharp geometries that seem carved… Unless they were shaped by strange phenomena of nature.

Some believe it’s the remains of an ancient city, sunken after an earthquake; others argue it’s purely geological. Today, it’s a riddle lying quietly under turquoise waters.

In 1918, a massive US Navy collier vanished without a distress call while crossing the Caribbean. More than 300 people disappeared with it, the single largest non-combat loss of life in U.S. Navy history.

No wreckage has ever been found. Storm? Structural failure? Something stranger? The sea has kept its mouth shut.

This line gets repeated a lot because it’s shockingly true. With sonar mapping still incomplete and most of the ocean floor left untouched by human eyes, researchers say we’ve charted only about a quarter of it in detail.

Mars, by contrast, has been mapped in full thanks to satellites. The ultimate plot twist is that we might understand another planet better than our own.

The 12 longest-living animals on Earth (and how they cheat time)

Nature doesn’t just create beauty, it crafts survival miracles. While most animals have short lives, a rare few have mastered the art of staying alive for centuries, even millennia. These aren’t just long-lived creatures; they’re nature’s ultimate time travelers. From the frozen depths of the oceans to the darkest corners underground, they’ve developed bizarre, brilliant strategies to cheat death. Get ready to meet 12 animals whose lifespans will absolutely blow your mind.

Record age: up to 15,000 years

This unassuming sea sponge thrives in the freezing waters of Antarctica, where temperatures hover around 28.6 °F—so cold that biological processes hit the brakes. In such icy conditions, metabolism slows to a crawl, allowing these sponges to live for thousands of years.

Some have reached impressive sizes of over 3 feet tall and have been around since mammoths were still thundering across the tundra. They don’t move, they don’t stress, and they barely change, just quietly existing while centuries pass them by. Their secret to extreme longevity? Glacial patience, deep-sea stillness, and a lifestyle that redefines "low-maintenance".

Age: technically… infinite

This tiny jellyfish, no bigger than a fingernail—less than 0.2 inches—is like the ocean’s very own Benjamin Button. What makes it truly extraordinary is its ability to rewind its life story, flipping back to a youthful, juvenile stage whenever it wants. While it’s not completely invincible (predators and other threats are still very real), if left undisturbed, it can keep hitting the reset button on aging indefinitely, making it one of the most fascinating "time-benders" in nature.

Record age: 507 years

In 2006, a special clam was discovered buried deep in the seabeds of the North Atlantic. Scientists were able to determine that it had been there since at least 1499—that’s centuries before the United States was even a thought! This ancient marvel, nicknamed "Ming", was able to perfect a slow-and-steady approach to life. Growing at a snail’s pace and barely budging, Ming’s sedentary lifestyle turned out to be a brilliant strategy for beating the clock. Who knew doing almost nothing could be the ultimate secret to longevity?

Record age: estimated 392 years

These sharks aren’t your average ocean cruisers—they can stretch over 20 feet long and weigh up to 2,200 pounds. But what’s really mindblowing is how slowly they move, like they’re in a permanent state of deep relaxation. Living in the icy Arctic waters, these giants don’t hit adulthood until they’re about 150 years old, and some can glide through the depths for nearly 400 years. Imagine that! These ancient swimmers were already around before America declared independence... and they are still out there, silently roaming the seas!

Record age: over 211 years

This whale is a true ocean giant, stretching up to 60 feet long and weighing a staggering 200,000 pounds. But what makes it stand out isn’t just its size but its age. Some of these majestic creatures carry harpoons from the 1800s still lodged in their skin, like walking history books. Just picture living so long that you’re literally carrying outdated technology embedded in your body—talk about being a time traveler of the seas!

Record age: 200 years

Spanning the chilly Pacific coastline from California all the way up to Alaska, this spiky little ball—about 7 inches across—is full of surprises. It munches on algae and calls the deep, dark ocean its home, thriving at depths of up to 300 feet. Don’t let its size fool you: this prickly creature is a true elder of the cold seas, quietly outliving many ocean neighbors while keeping a low profile. A tough, slow-living veteran wrapped in spikes!

Record age: 226 years

Meet Hanako, a legendary Japanese koi who swam through life for an astonishing 226 years. Scientists discovered how old she was by studying the rings on her scales, much like counting the growth rings of a tree. These colorful, ornamental fish aren’t just symbols of good fortune; they’re also secret long-lifers with the potential to celebrate over two centuries of birthdays, as long as they get the right care and a peaceful pond to call home.

Record age: 190 years

Jonathan is a male tortoise living on the remote island of Saint Helena in the South Atlantic Ocean. He was born back in 1832, and he’s still happily chomping lettuce and soaking up the sun today. Weighing in at more than 400 pounds and measuring around 3 feet long, Jonathan holds the title of the oldest known living land animal on the planet. If he could share tales, they’d span nearly two centuries of history. Imagine that!

Record age: 152 years

This ancient-looking fish, with its whisker-like barbels, looking like a tiny underwater submarine, prowls the lakes of North America. It can reach an impressive length of up to 7 feet and weigh around 200 pounds. These slow-living creatures don’t rush into adulthood—they start breeding only around age 20—and then take their time cruising through life at a leisurely pace. Believe it or not, one legendary catch in Wisconsin was estimated to be over 150 years old!

Record age: over 90 years

This chunky, night-loving parrot from New Zealand is a true oddball—it can’t fly, snores like a grumpy grandpa, and smells like fresh flowers. Despite its quirks, this bird boasts an impressively long lifespan. Sadly, it teeters on the edge of extinction. The oldest known kakapo, affectionately named Richard Henry, lived 90 years, earning him the title of the charmingly eccentric elder statesman of the avian world.

Record age: 37 years

This tiny, kooky rodent—barely 3 inches long and just over an ounce in weight—could’ve been cast straight from a sci-fi apocalypse flick. Dwelling in vast underground colonies across Africa, it’s practically invincible to cancer, pain, and the usual effects of aging. Scientists are fascinated by this little marvel, even if it’s not winning beauty contests anytime soon. Its superpowers make it a star in longevity research!

Record age: estimated 100+ years

Lobsters have a totally different rulebook than us when it comes to aging. They don’t really grow old; they just keep getting bigger and bigger. Some giant lobsters weigh over 40 pounds and stretch beyond 3 feet long. Their biggest threats? Not old age, but predators or the risky process of shedding their shells. In theory, they could live forever if left alone—but let’s be honest, not many get to enjoy a peaceful, lobster-sized retirement!