What are these strange objects found in ‘bottomless pit’ at New Mexico cavern?

Archaeologists have a sixth sense when it comes to things that don’t belong and one such instance presented itself recently when 16 pebble-sized artifacts were found in ancient pits at Carlsbad Caverns National Park.

After determining the objects were foreign to the cave system in New Mexico, the park service invited the public to weigh in and figure out something park rangers learned only after scrubbing the objects.

“What are the items?” the park asked on Facebook, offering a series of hints. “They are all the same thing. ...They are not living nor are they from a living thing.”

The answer? Extremely corroded U.S. pennies.

It’s believed the coins were tossed by tourists hoping to see (or hear) if the cave’s infamous pit had a bottom.

“Rangers cleaned these out of a pit in the Big Room,” the park revealed. “Please do not throw coins and trash into cave pits and pools.”

The Big Room is a 357,480-square-foot cavern that is “the largest single cave chamber by volume in North America,” according to the National Park Service.

It includes an officially named “Bottomless Pit,” which park officials say actually does have a bottom.

“For early explorers without strong lights, this gaping hole appeared bottomless. From the trail, the bottom is 140 feet (40 meters) down,” the park revealed on Facebook.

The pit has to be cleaned out on a regular basis, because debris thrown in by tourists can pollute the water and damage the slow growing rock formations. “These foreign materials will discolor the water and rocks, and can upset the cavern’s ecology,” the park posted on Facebook.

As for the 16 pennies found in the pit, the park service did not reveal the dates on them, or give an estimate of how long they had been in the pit.

This story was originally published July 10, 2020 at 12:56 PM with the headline "What are these strange objects found in ‘bottomless pit’ at New Mexico cavern?."