NOVA

- I can tell you unequivocally that the government does keep secrets when it comes to aerospace technology.

The Pentagon has what we often call a black budget, which can sometimes exceed $65 billion in a year.

- Even within the military, there's never been a consensus really that it's this or that or that it's not extraterrestrial.

- We cannot rule out extraterrestrials, but you have no evidence for it.

It comes back to the evidence.

- Regular citizens have been reporting things for decades, and yet we hear nothing from the government about what this may be.

- And now that we have more observations, more cameras, more cell phones that are taking pictures of phenomenon in our atmosphere, scientists need to come forward and talk about how we can identify these objects.