Phil Plait, who works in the physics and astronomy department at Sonoma State, has made it his mission to clear up misconceptions about astronomy. One of his targets, as the main guest on Monday's show, was the work of maverick physicist James McCanney. He's just plain wrong about comets not being made mostly of ice and rock and in his assertion that comets can be as large as planets, Plait said. He cited a probe that measured Halley's Comet and found it to be only 10 miles long back in 1985/6.

He also took aim at the recent Harmonic Concordance, which was considered by many to be a celestially significant event as the Sun, the Moon, Mars, Jupiter, Saturn, and Chiron formed into a Star of David pattern over a two-day period. But Plait noted that the pattern doesn't hold up if it's taken into account that these objects are at vastly different distances from the Earth.

For more on his comments on these and other "bad astronomy" topics view the special page he created for this program, as well as the article below.

JFK Assassination Special

First hour guests Scott Rubins & Paul Dowling of Court TV discussed their upcoming Forensic Files special The JFK Assassination: Investigation Reopened. While there were many mistakes made in the autopsy, "I don't think there's a conspiracy here," said Rubins. Dowling said every piece of forensic evidence lead back to the 6th floor window tying Oswald to the rifle. "If there was a grassy knoll shooter, he missed him," Dowling added.