It’s more than 100 feet long, at least 300 years old and visible from space. The world’s largest coral has just been discovered in the southwest Pacific Ocean, scientists announced Wednesday. The mega coral was spotted during a scientific expedition launched by the National Geographic Pristine Seas program in October to study ocean health in the Solomon Islands.

It’s three times larger than the previous record-breaker in American Samoa, according to Pristine Seas, and longer than a blue whale, the planet’s biggest animal. Unlike a reef, which consists of many colonies, this coral is a single specimen that has grown continuously for centuries. “Just when we think there is nothing left to discover on planet Earth, we find a massive coral made of nearly 1 billion little polyps, pulsing with life,” said Enric Sala, National Geographic explorer in residence and founder of Pristine Seas.

The coral looks like a huge, undulating brown rock from above. Some on the expedition even initially mistook it for a shipwreck. Marine biologist and underwater cinematographer Manu San Félix dived down to look. “In the first second I realized that I was looking at something unique,” he said. It’s “close to the size of a cathedral.” Scientists later checked satellite images and found the coral is so colossal, it was possible to see it from space. (CNN)

Photo: An aerial view of the world’s largest coral, under the stern of a research boat, discovered in the Solomon Islands last month.