An array of radio towers sits behind security fences amid farms and pastures north of Fort Collins. This is home to WWV, the country's oldest radio call letters. The station's high-frequency broadcasts can be heard around the globe if you have the right kind of radio.

Now playing: pulsing sounds, every second, followed by an announcement of the exact time.

The station is run by the National Institute of Standards and Technology in Boulder, which is home to the atomic clock. WWV is capable of more than telling time. It could, if need be, save the world.

"Could be," said Elizabeth Donley, chief of NIST's Time and Frequency Division. "It's an important part of our work."

This year the station conducted communications exercises in coordination with the Department of Defense. Thirty-seven states, National Guard units, emergency management agencies and others participated in simple announcements. They were meant to see how many listeners are out there and how far away they can be reached. The answer: there are thousands of listeners as far away as Australia and New Zealand.

Mark Jensen, a civilian planner with U.S. Northern Command, the military's homeland security operation in Colorado Springs, called WWV a "most essential asset to our nation."

Should an emergency arise, volunteers would jump into action. They're part of a program the military dubs MARS, which stands for Military Auxiliary Radio System. While jokes abound that the operators should not be confused for Martians, their work is serious. It's doomsday stuff, like responding to the aftermath of a nuclear attack because the associated electromagnetic pulse could wipe out most communications.

Or this scenario: extreme sun activity releasing masses of plasma accompanied by an unruly magnetic field.

Credit National Institute of Standards and Technology / National Institute of Standards and Technology NIST radio station WWV's transmitter building in Fort Collins. This station broadcasts time-of-day information to the Continental United States.

Paul English, chief of the Army's MARS program, said operators are training — just in case.

"There have been instances where those coronal mass ejections could be so large that they have an adverse impact on electronics and communications," English said.

That could mean mobile phones wouldn't work. Computer screens could go blank. Vehicles might not run. There might be runs at banks and shortages of food and fuel.

"That's where our MARS operators will reach out the amateur radio community and just ask some simple questions," English said.

For instance: Are there long lines at hospitals? How are the roads? And so on. It's what the military calls situational awareness, necessary for its responses.

It's also where WWV could fit in.

"With their high-power transmitters, we would look at WWV as a source to get out information," English said.

Yet the station was almost shuttered. NIST's budget request for the 2019 fiscal year had proposed closing WWV and its sister station, WWVH in Hawaii, to save more than $6 million. The cuts never came.

Asked about any future budgets, NIST's Donley said, "We actually work with the president to try to meet the president's goals. Over the past few years there's been some big cuts that were threatened that didn't materialize so far."

WWV was created in 1919. It began test broadcasts in Washington, D.C., of concerts on Friday evenings in 1920.

"This means that music can be performed at any place, radiated into the air by means of an ordinary radio set, and received at any other place even though hundreds of miles away," a press release from the time stated. "The music received can be made as loud as desired by suitable operation of the receiving apparatus."

Later, it broadcast agricultural reports. Then WWV became a standard for frequencies that broadcasters used to correctly calibrate their radio signals to prevent overlap.

In the ensuing decades, the station operated from Maryland. Broadcasts of clicks every second began in 1937 (today they're pulses). An announcer stating the exact time was added in 1950. In 1966, the station was relocated to Fort Collins.

Credit Michael de Yoanna / KUNC / KUNC WWV's 100th anniversary cake.

Tuesday marked the station's 100th anniversary. Under a tent in a field outside the station, dozens of scientists, radio operators and others gathered to celebrate the station's past as well as to reflect on its possibilities in the future. Beyond playing a role during an emergency, WWV might also be key to cutting-edge science.

That's according to Philip J. Erickson, the assistant director of MIT's Haystack Observatory. He is interested in how WWV could be used to help study the atmosphere.

"WWV itself is a very important — and future-oriented by the way — remote sensing tool, much more than the convenient way to set a watch," he said. "For us it a real way to increase understanding of upper-atmosphere variations which are labeled space weather."

He indicated that modern crowdsourcing make for some interesting possibilities. Shortly after, a cake with a tiny replica of the station was cut in honor of WWV's centennial.