Leslie Mullen, the host of NASA's podcast "On a Mission," warned that there are a number of asteroids in space that can destroy the Earth and cause mass extinction. Mullen noted that many of these massive asteroids have not yet been detected by NASA.
The media producer of NASA made the chilling statement during a recent episode of "On a Mission" titled "The Sky Is Falling." During the episode, she and her guest astronomer Greg Leonard discussed the threats posed by asteroids on Earth.
According to Mullen, Earth gets hit by hundreds of small asteroids every day. Due to their small sizes, many of these asteroids burn out in Earth's atmosphere before reaching the ground.
"Our planet is in the middle of a cosmic shooting gallery," Mullen said during the episode. "Asteroids often fly by, and the Earth is hit every day with hundreds of tons of dust grains and small rocks."
"Most of them burn up in the atmosphere, and sometimes we see them as meteor showers or shooting stars," she added.
There are slightly bigger asteroids that also tend to approach Earth from time to time. As noted by the host of NASA's podcast, the space research organisation regularly maintains a database to keep track of the near-Earth approaches of all known asteroids.
Although some of the asteroids in the database are big enough to wipe out an entire city or town, Mullen noted that none of these are on a collision course with Earth at the moment.
Unfortunately, this doesn't mean that Earth is safe from getting hit by a planet-killer asteroid. According to the media producer, there are still a high number of asteroids in space that NASA has not yet detected or identified. Some of these could be as big as or even bigger than the asteroid that wiped out the dinosaurs 66 million years ago, which is estimated to be about 81 kilometres wide.
Mullen said that if these unknown monster asteroids hit Earth, the entire planet will most likely get destroyed. "The small rocks from space do little to no damage," the podcast host said. "It's the big ones we worry about. And there are big asteroids out there, lurking in the dark, large enough to take us out."
"Currently, none of the really big asteroids are headed for us," Mullen continued. "But we haven't found them all."
