The most fascinating irony in human exploration is that we know more about the surface of Mars or the Moon than about the bottom of our own planet's oceans. More than 80% of the global ocean remains unmapped at a detailed resolution, and only a small portion has ever been directly seen or explored by humans or robotic vehicles.
Oceans cover more than 70% of Earth's surface and have an average depth of 3,688 meters. The deepest known point, the Mariana Trench in the Pacific Ocean, reaches a depth of 11,034 meters โ far deeper than the height of Mount Everest. At this depth, water pressure reaches 1,100 times atmospheric pressure โ a pressure that would destroy most human-made equipment.
Despite these challenges, the most surprising fact is that we have surface maps of the Moon and Mars with far better resolution than the seafloor of our planet. This is because mapping the ocean requires slow and expensive ships or underwater vehicles to conduct sonar mapping, while the surfaces of the Moon and Mars can be mapped from orbit using satellites.
Life in the unexplored deep sea continues to surprise scientists every time they investigate it. Ecosystems around hydrothermal vents on the ocean floor depend not on sunlight but on chemosynthesis โ a process where bacteria produce energy from chemicals. These discoveries have changed the way we think about the possibility of life on other planets, including Europa, one of Jupiter's moons, which is believed to have a liquid ocean beneath its icy crust.