NOVA

- [Narrator] When it comes to sightings of UFOs by military pilots and the public, how can science help separate fact from fiction?

- [Mark Mountain] From the very days that Galileo first lifted his telescope to the sky and made measurements of the moons going around Jupiter, everybody else could then reproduce those measurements and go, oh yeah, he's right.

And that confirmation is what has made the scientific method so powerful over the last 400 years.

- [Shelley Wright] The thing we need is data, and we need real data, and we don't have it.

- [Narrator] Astronomer Avi Loeb is collecting more data in a novel way.

- [Avi Loeb] We just constructed an observatory at Harvard University.

We are monitoring objects that fly overhead and trying to make sense of them.

- [Narrator] This collection of instruments is part of Harvard's Galileo Project.

- [Jacob Haqq-Misra] The Galileo Project is developing several sites that are spread across a geographical region where each site has an array of sensors, optical cameras, infrared images.

There's audio from infrasound to ultrasound.

There's radar.

It's a wide array of instruments to basically look at the sky all the time to see if you find any anomalies.

- [Narrator] Some instruments have other worldly names like this one called Dalek... - Dalek: Exterminate!

- [Narrator] ...after the cyborg aliens featured in the Dr. Who series.

Inside Dalek, there are eight infrared cameras.

- [Loeb] They get the full picture of the entire sky at all times in the infrared.

When something of interest is identified by the main set of cameras, we zoom on it in the sky.

And this is the camera that can move around and look at the object of interest, automatically based on the computer system that we developed.

- [Haqq-Misra] You can imagine if you have a camera pointing overhead, you're gonna see a lot of things that are identifiable.

So they use machine learning, what people call artificial intelligence that can recognize the knowns, recognize the birds, the airplanes, the balloons, leaves, all the known things, and sort of reject those, filter them out.

And then what you're left with is the anomalies.

You're left with things that you cannot understand, the things you can't identify.

- [Loeb] So far, we have been operating this observatory for several months, and we saw hundreds of thousands of objects in the sky.

None of them appears to be anomalous, but even if one in a million came from outside of this Earth that would be big news to humanity and will change our future.

And that's what drives my science.

(dramatic music) - [Narrator] And there's another way we can collect more data with a little help from the public.

- When they're coming in, it will seem like they're going sideways.

- [Narrator] In the lower east side of Manhattan at Enigma Labs, a staff of software designers and UFO enthusiasts are developing a first of its kind crowdsourcing app.

- [Lauren Butler] The goal is really to bring people together to share their UAP experiences and their sightings.

- [Alejandro Rojas] We get a lot of Starlink and SpaceX rocket videos, but at the same time, people are submitting things that cannot be explained.

This time, I've got one that I can't figure out.

Maybe you can help me out.

This is really cool.

Just this light comes floating in, and then it hovers.

But wait.

- But what is this blob of light here?

- It came down slowly, right?

- [Rojas] Yeah.

- [Butler] Those are fireworks, Isaac, right?

- [Rojas] Those are probably fireworks.

- Probably smoke rising up though.

- [Rojas] And smoke rising up.

But in just a second it will get weirder.

- What?

- [Rojas] Isn't that weird?

- It gets brighter and brighter.

- Oh, it's getting brighter.

- [Rojas] Yeah, it keeps getting brighter.

And it's a broad beam of light.

- So it's not a star.

- [Rojas] So what do you think about maybe drone?

But I mean, look how still it is.

It doesn't have blinking lights.

I mean, it doesn't look like a drone.

This is a good one.

I don't know.

I don't know what that is.

- [Narrator] Apps like this could one day be a source of data for scientists to study.

- [Mountain] We're not relying just on, did you see something?

We're asking your cell phone to make a measurement.

It's going to record the position of the phone on the planet 'cause we all have GPSs in it.

And because it has a little compass in it, it will also tell us what direction we're looking at, so we can actually do scientific experiments with actual data because our modern cell phones are so good now at recording numbers.

- [Wright] As scientists, we also wanna get to the bottom of this.

- [Hakeem Oluseyi] The answer is get more data, and the way you're gonna get more data is that you're gonna have more eyes on the sky.