At some point, we have all learned about how an asteroid crashing on the Earth brought about the end of the dinosaurs. Amir Siraj, professor Avi Loeb, and others from Harvard University believe that the object was actually a comet rather than an asteroid. More specifically, one that came farther away than we had previously imagined.

They believe that the comet that struck Earth was a part of the Oort cloud, located at the edge of the solar system. Essentially it was pulled into the solar system by Jupiter’s gravity. The gravity shot the comet into orbit, passing it close to the sun where it broke into pieces. In turn, some fragments of the comet entered Earth’s orbit where one fragment crashed into the coast of Mexico.

However, some researchers like Bill Bottke, a planetary scientist at the Southwest Research Institute in Boulder, Colo., believe that this theory has many flaws. He told The New York Times: “I believe their work has several intrinsic problems.”

Siraj and Loeb have evidence pointing towards this extraterrestrial object being made of carbonaceous chondrites. A rocky material dating back to the birth of the solar system and found in a class of primitive asteroids. Assuming that their model and evidence are correct, then the date of the impact would have been around 66 million years ago.

Mr. Siraj and Dr. Loeb are hopeful that future samples may help shed light on their hypothesis. Others are also optimistic that advances will help with the creation of new theories on how the dinosaurs were wiped out, as well as prevent or prepare for future events similar to this one.