Asteroid 2014 DX110 will come within 218,000 miles of Earth on its closest …218,000 miles of Earth on its closest approach on March 5th, 2014. … Slooh Space Camera will track the asteroid as it passes by Earth. Sixty-five million years ago, a gigantic asteroid collided with Earth. Sixty-five million years ago about 70% of all species then living on Earth disappeared within a very short period. The disappearances included the last of the great dinosaurs. Paleontologists speculated and theorized for many years about what could have caused this “mass extinction,” known, as the K-T event (Cretaceous-Tertiary Mass Extinction event). What would happen if another giant asteroid found itself on a collision course with Earth? This is a future possibility.