The Defense Department issued a legal waiver authorizing current and former personnel to share unidentified anomalous phenomena–related classified information, but it doesn’t extend to other agencies.

The US government has been sharing more information about UFOs. That's fueling excitement over the possibility of the president announcing that humans are not alone.

The impact will kick up a plume of debris so high, it’ll likely be visible through some telescopes. Astronomers will be watching.

Previous landmark scientific discoveries like the Higgs boson provide a better template for what it will take to confirm whether aliens have made contact with Earth.