A recently learned item about Tycho
About 160 million years ago, a large Main Belt planetoid broke up,
creating the Baptistina planetoid family.
One of these objects struck Earth's Moon 108 million years ago,
creating the crater Tycho. Another member of this family hit Earth
directly 65 MYA, causing the extinction of the dinosaurs.
“An asteroid breakup 160 Myr ago as the probable source of the K/T impactor,†Nature, september 6, 2007