What is written in the book about the Bakaratinian catastrophe is DEFINITELY a real scenario:
"Asteroid Close Encounter Coming Wednesday"
http://news.nationalgeographic.com/news ... tatis.html
...asteroid named 4179 Toutatis is expected to pass within a million miles (1.6 million kilometers) of Earth on Wednesday.
"The September 29 … approach is the closest in this century of any known asteroid at least as big as Toutatis," said Steven Ostro, who studies asteroids at NASA's Jet Propulsion Laboratory in Pasadena, California.
Radar images of the three-mile-long (4.6-kilometer-long) asteroid...
...
Ostro and his colleagues have studied the orbit of Toutatis more closely than any other known near-Earth object its size. The scientists say with confidence that the asteroid poses no risk of impacting Earth at least through 2562, when Toutatis will pass within 250,000 miles (400,000 kilometers) of Earth.
"We can't see the future beyond that close approach, and we must know exactly how close it will be to [project] the orbit out further [in time]," Ostro said.
So is there any chance that Toutatis may hit Earth in the future?
"The answer is obviously, yes," Ostro said. "There's a good chance [of Earth impact] in the next several tens of millions of years. But you could make that statement about any one of the near-Earth asteroids."