You have seen it play out in movies like Paramount's Deep Impact, but could an asteroid land on a collision course with planet Earth? It certainly has happened before. 

Dr. Richard Binzel is a leading astronomer and professor at MIT. Binzel and his team have been tracking asteroid 2024 YR4 for months. It was first identified by NASA late last year and has been monitoring its chances of colliding with Earth on December 22, 2032. 

On Tuesday, NASA rated the probability of a collision at 3.1%. That is the highest likelihood ever given in the agency's history. By Wednesday evening, NASA had lowered it to 1.5%. 

"As we get more and more measurements, we keep tracking the asteroid, that uncertainty window, that broad range of where it could go it's going to shrink and shrink," said Binzel. "Until the Earth falls outside of that pathway, we're going to see these probabilities bounce around."

Binzel says this asteroid would likely dissolve on approach. He created the Torino scale, which NASA uses to measure the threat of incoming objects. This asteroid registers at a three, a 10 took out the dinosaurs. 

"These things are out there. They have always been out there," Binzel said. "So really it's just a measure of our capability [to spot them] as much as anything." 

At its highest probability of 3.1%, NASA had the odds of a collision at 1 in 32. People in and around Cambridge had thoughts on that likelihood. "It is what it is," said one woman. "That's all I'm saying if it happens it happens. This is Earth, this is nature, you don't have any control over it. Nobody does." 

Anthony Attardo said, "This has been a topic of conversation among my friends. A 3% chance of dying is actually not that big. I almost just fell [on ice] before you talked to me, so it could be much worse." 

Binzel said NASA will continue to hone in on the asteroid's path over the next few months and should be able to determine whether it is out of the window of possibility. Until then, he said, much like the forecast for a hurricane, you can expect the percentages to fluctuate.