Mysterious "Golden Orb" Identified by NOAA Scientists

The now two-and-a-half-year-old mystery of the "golden orb," an unidentified object that captured significant public interest when it was collected during a 2023 NOAA expedition, has finally been solved.

Scientists have determined that the mysterious golden mass, discovered at a depth of 3,250 meters (over 2 miles) in the Gulf of Alaska, is a remnant of the dead cells that formed at the base of a giant deep-sea anemone, Relicanthus daphneae. It was the part of the anemone that attached to the rock substrate.

During NOAA Ocean Exploration expeditions on NOAA Ship Okeanos Explorer, it’s common for scientists to find organisms they don't immediately recognize. Most of the time, these mysteries are solved quickly as members of the scientific community chat and pool their knowledge. However, some discoveries turn into real puzzles — like in the case of the “golden orb.”

The backstory

In 2023, during an expedition in the Gulf of Alaska, remotely operated vehicle Deep Discoverer (launched from Okeanos Explorer) was exploring at a depth of over two miles when it encountered a strange, golden, mound-shaped object with a hole in it, stuck to a rock. Scientists were puzzled. Was it an egg case? A dead sponge? Had something crawled into it … or out of it?

The mysterious discovery attracted a lot of speculation and public interest. Hoping to find answers, the at-sea team collected the orb using a suction sampler and sent it to the Smithsonian National Museum of Natural History (NMNH) for further examination and study.

Unraveling a scientific mystery

Identifying the "golden orb" was a multi-year, complex effort. In a world accustomed to instant gratification, waiting for scientific research to provide answers can be frustrating. But science takes time. So how did scientists determine what the golden orb is?

“We work on hundreds of different samples and I suspected that our routine processes would clarify the mystery,” explains Allen Collins, Ph.D, zoologist and director of NOAA Fisheries’ National Systematics Laboratory, which is physically located within the Smithsonian National Museum of Natural History. “But 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.”

Scientists with NOAA Fisheries and the Smithsonian National Museum of Natural History used an integrative taxonomic approach combining a study of its physical structure with genetic analysis to identify the object. Initial examination found the object lacked typical animal anatomy but was a fibrous material with a layered surface packed with cnidocytes (stinging cells), suggesting it was a cnidarian (like corals or anemones). National Systematics Lab scientist Abigail Reft identified the cells as spirocysts, which are limited to the Hexacorallia group of cnidarians. The team also examined a similar specimen collected in 2021 during an expedition on Schmidt Ocean Institute’s Research Vessel Falkor and found similar cnidocysts.

Initial DNA barcoding was inconclusive, likely due to picking up DNA from other microscopic life on the specimen. Moving deeper, whole-genome sequencing confirmed animal DNA and contained a large amount of genetic material from the giant deep-sea anemone. Sequencing the mitochondrial genomes of both specimens confirmed they were genetically almost identical to a known Relicanthus daphneae reference genome.

Deep-sea secrets still to be found 

Mystery solved: The “golden orb” is not an egg, a sponge, or remnants of a space alien, but a relic of a deep-sea anemone. While this discovery confirms the identity of the previously unknown specimen, the Earth’s deep ocean still holds many secrets.  

“So often in deep ocean exploration, we find these captivating mysteries, like the ‘golden orb.' With advanced techniques like DNA sequencing, we are able to solve more and more of them," said CAPT William Mowitt, acting director of NOAA Ocean Exploration. “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.”