Would NASA tell us if we were about to go the way of the dinosaurs?

The short answer is yes. At least, that's the response NASA astronomer Michelle Thaller gave on educational YouTube channel Big Think when asked.

“I often get asked this question,” Thaller said. "If scientists actually knew there was an impending catastrophic collision, some asteroid was heading towards Earth, would they tell you?"

"And the answer is yes... Every night we are looking for objects that might be on a collision course with Earth and if we find anything that looks risky, we inform lots of people."

As she points out, hiding a large chunk of rock as it hurtles towards the Earth might be a hard thing to accomplish – even if NASA wanted to. 

"There are telescopes everywhere on the planet. There’s no way that anybody could hide the fact that some big asteroid was on a course with the Earth."

But one of the hardest things for Thaller to understand is how anybody expects scientists to keep a secret that big. Or why they would want to. She recalls a conversation she had at the tail end of 2012, one week before the Mayan apocalypse was apparently going to wipe us all out. The caller wanted to know if she knew if the world was going to end or not.

"There was nothing happening astronomically that we could tell, but I realized this person didn’t think of me as an actual human being," she said. "That if I knew the world was going to end in a week, I would be at work at my desk? I don’t think so."

"The day you have all the scientists buy up all the great wine and max out their credit and disappear. Then you might want to worry."

So there you go, that's how to tell if the world is about to end. Hopefully, it won't come to that – even if there is an incoming asteroid. While the planet is a little underprepared for a large asteroid attack as of right now, NASA is working on a number of possible solutions for when the time (inevitably) comes, one of which would involve flinging spacecraft directly into the rock to knock it off course. Another involves using a nuclear bomb in a similar vein to Bruce Willis in Armageddon.

Fortunately, it doesn't look like there are any large asteroids currently set to collide with Earth any time soon but if you want to check the probability of some of the potentially hazardous asteroids (PHAs) set to fly by Earth before 2020, there is impact risk data here. The far more likely scenario is that we see something smaller and harder to detect, like the Chelyabinsk meteor that struck Russia in 2013.

As many as 25 percent of asteroids that could hit us are thought to be unknown and while they are very, very unlikely to destroy life on the planet as we know it, they could have the power to destroy a city.

So, it seems we don't have to be too concerned about death by asteroid just yet but could NASA be hiding the evidence of aliens? Again, probably not. Thaller believes it's extremely likely we'll all find out about alien life very shortly after the experts.

But whether this will convince everyone, we're not so sure.

"We are people and if we knew something dangerous was coming, there would be no way for us to hide it." Big Think/Youtube