The Moonstone disc displayed in the museum is a replica of a real bronze age artifact: the "Nebra sky disc" (Himmelsscheibe von Nebra), found 1999 near Nebra, Saxony-Anhalt in Germany. The description given by Catrina is spot on: dated around 1600 BC, and probably used to harmonize the moon and the sun year (354 vs. 365 days).
Character Mags Dormer's nickname "Mystic Mags" is a reference to Mystic Meg (aka Margaret Lake) who was briefly famous in the mid 1990s when she used to appear on The National Lottery (1994), foretelling who might win money on the lottery.
The chances of being hit by a meteorite are about 840,000,000 to one avoiding to various studies since any meteorite is more likely to burn up in the atmosphere and very few make it to the ground. There is only one recorded case of a meteorite hitting a person and they survived.
At one point, Barnaby does a web search. The list of results has the normal Google format and layout. At the top of the screen is the bottom half of what should be the word "Google" (in the usual font and colours). Although only the bottom half of the first word and start of the second word is visible, for a split second, it actually, obviously, says "Big-Brow..." rather than Google (or the previous text given here - "Big Brother"). Possibly it was meant to be "Big-Browser"?