A bizarre discovery more than two miles beneath the surface of the Gulf of Alaska had scientists puzzled for years, after a remotely operated vehicle from the National Oceanic and Atmospheric Administration uncovered a strange golden object clinging to a rock. Now, after a complex scientific investigation spanning multiple disciplines, researchers say the mystery has finally been solved.

A Discovery in the Deep That Defied Explanation

The unusual object was first spotted in 2023 during a deep-sea exploration mission in the Gulf of Alaska. NOAA researchers say their remotely operated underwater vehicle was operating more than two miles below the surface when it encountered what appeared to be a “strange, golden, mound-shaped object with a hole in it, stuck to a rock.”

The find immediately stood out as something unfamiliar in the deep ocean environment, prompting scientists to carefully recover it and transport it to the Smithsonian National Museum of Natural History for further study.

A Scientific Puzzle That Refused Easy Answers

Allen Collins, director of NOAA Fisheries’ National Systematics Laboratory and a zoologist, said scientists initially believed the object would be easy to identify.

"This turned into a special case that required focused efforts and expertise of several different individuals. This was a complex mystery that required morphological, genetic, deep-sea and bioinformatics expertise to solve," Collins said.

What began as a routine identification process quickly escalated into a multi-year investigation involving advanced genetic sequencing and detailed structural analysis.

Inside the Golden Orb’s Strange Structure

Early examination revealed something unexpected. The object did not show typical animal anatomy. Instead, researchers found it was composed of a “fibrous material” covered in stinging cells similar to those found in anemones and coral.

Those cells were identified as spirocysts, a specialized type of cell used to capture prey. Spirocysts exist only in cnidarians, a group of aquatic invertebrates that includes sea anemones and jellyfish.

This clue narrowed the search significantly, but the exact identity of the object remained unclear.

A Breakthrough Hidden in a Past Discovery

The investigation took a turn when scientists noticed similarities to a specimen collected in 2021. When the golden orb was compared to that earlier sample, researchers determined they belonged to the same species.

Initial DNA testing did not provide clear answers. However, whole-genome sequencing eventually revealed that both samples were “genetically almost identical” to a cnidarian known as Relicanthus daphneae.

Further analysis led to a striking conclusion.

NOAA explained in a video that the orb “had once been part of the base of a giant sea anemone.”

What Happened to the Missing Anemone

Scientists now believe the golden object is a structural base that normally remains hidden beneath a giant sea anemone. Somehow, this portion was separated and left exposed on the seafloor.

The full organism is still something of a deep-sea giant. Researchers say it has a pink-colored cylindrical body that can grow up to three feet across, with tentacles reaching as long as six feet. Its spirocysts are among the largest known in all cnidarians.

What remains unclear is what happened to the rest of the anemone. NOAA suggests it may have died or moved to a different location, leaving the base behind.

A Window Into the Unseen Ocean

“So often in deep ocean exploration, we find these captivating mysteries, like the 'golden orb,'" said NOAA Ocean Exploration acting director William Mowitt. "With advanced techniques like DNA sequencing, we are able to solve more and more of them. This is why we keep exploring—to unlock the secrets of the deep and better understand how the ocean and its resources can drive economic growth, strengthen our national security, and sustain our planet."