[bright music] - [Narrator] The simple act of looking at a photo is kind of like entering a time machine.

The images transport you through time and space.

In a sense, the same thing happens when you turn your eyes to the night sky.

The universe is so vast, the light you're seeing actually left those stars millions of years ago.

Again, you become a kind of time traveler.

- [Researcher] February 13th, 1939.

- [Narrator] So these secure rooms at the Pisgah Astronomical Research Institute in Western North Carolina are a true time capsule.

- September 13, 1921.

Now, this particular set of plates, and this particular star...

There's over 100 of these little plates, and they're taken over a time period.

It could be all the way up to the '70s.

They were trying to record any changes that the star might go through and experience, and learn from it, as far as evolutionary path of a star.

[bright music] - [Narrator] This is the Astronomical Photograph Data Archives.

- The best way to take this out, I'm gonna set this here, and you'll lift up.

And there's the glass plate.

Now, one would want to find where the emulsion is, where the chemicals are put to take an image.

- [Narrator] By the late 1880s, photos of the night sky were etched onto glass plates.

One side was covered with an emulsion.

The brighter the image, the darker the spot on the glass plate.

The field of image was five degrees by five degrees.

For perspective, the full moon covers about a half degree.

The astronomer typically looked at whatever the topic of research was about, and put the plate away.

But images of that size contained hundreds of things nobody had looked at before, each image a unique record of a specific time and place, and a history of optical astronomy.

- [Thurburn] This is a print of a glass plate, and that glass plate is right here.

So as you can see, it's in black and white.

I don't know what you can see through it, or not.

Okay, we're gonna set it back down.

This part is not the emulsion side, the other side is, so it's safe if you accidentally touch it.

[bright music] - [Narrator] Since the archive's creation in 2007, the facility has played a vital role in collecting, preserving, and curating a comprehensive collection of photographs of the night sky from some of the world's greatest observatories.

The archives houses almost a half million images.

- We have a collection from Cerro Tololo Inter-American Observatory in Chile, which are those two cabinets down this way.

Kitt Peak National Observatory.

We have some from, well, of course, Case Western Reserve, University of Michigan.

We have, let's see, United States Naval Observatory.

We have about 128,000 of their images.

- [Narrator] NASA built the facilities in the 1960s as the Rosman Satellite Tracking Station for tracking manned and unmanned space missions.

By the 1980s, it was transferred to the Department of Defense to eavesdrop on foreign communications.

After the Cold War, it was transferred to the nonprofit.

Who knows what mysteries and great leaps in astronomy discoveries are waiting?

It all starts with a true record of everything we see.