At over 8,000 feet beneath the Atlantic Ocean, scientists spotted an unusual line of almost perfectly-spaced holes. The little pits, near the Mid-Atlantic Ridge, have baffled researchers. 

"The origin of the holes has scientists stumped," tweetedthe U.S. National Oceanic and Atmospheric Administration.  The agency explored the sea floor with a remote-operated vehicle, or ROV.

The expertly-aligned holes make it appear that they could be from human activity. But a key scientist isn't nearly convinced. "I don't think they're human-made," Mike Vecchione, a zoologist at the National Museum of Natural History who worked on and watched the dive remotely, told Mashable.

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Though Vecchione notes the evidence is scant, he has two different hypotheses:

• An animal could have burrowed through the sea floor horizontally, and occasionally pushed up holes to get fresh oxygenated water for ventilation.

• A creature swam just above the surface of the sea sediment and occasionally poked something down into the sandy floor. "Sort of the way that shorebirds feed when you go to the beach. You'll see birds walking along the edges of the surf and they're poking their bills down into the sand every once in a while," Vecchione explained. 

This is not the first time scientists encountered such mysterious holes. In 2004, Vecchione and marine researcher Odd Aksel Bergstad witnesseda similar set of holes during a dive to the Mid-Atlantic Ridge. However, no one has invested money and time to investigate why these holes form, Vecchione explained. (Deep sea exploration is expensive and demands lots of personnel.)

But during this recent expedition, marine researchers collected water samples from the holes to detect environmental DNA, which is genetic material an organism left in the environment. This DNA can tell what kind of animals are in the vicinity. But researchers have yet to analyze the water sample. 

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In his career, Vecchione has witnessed some extremely wild critters and events in the deep sea. So he knows the ocean is full of marine mystique that's almost certainly responsible for these holes. Though he's seen the internet propose some, let's say, far-out extraterrestrial ideas.

"I've seen a lot of really wild speculation over the past few days," Vecchione said.