Template:Are You Sure/October 7
• ... that 2008 TC3 was an asteroid that entered Earth's atmosphere on October 7, 2008; that it exploded at an estimated 37 kilometers (23 mi) above the Nubian Desert in Sudan; that some 600 meteorites, weighing a total of 10.5 kilograms (23.1 lb), were recovered, some containing nanodiamonds; and that it was the first time that an asteroid impact had been predicted before its entry into the atmosphere as a meteor?
• ... that a derangement is a permutation of the elements of a set such that no element appears in its original position; and that the principle of derangement was first considered by mathematician Pierre Raymond de Montmort in 1708, and that he solved it in 1713, as did Nicholas Bernoulli at about the same time?
• ... that mathematician Olga Taussky-Todd (30 August 1906 — 7 October 1995) was hired by a group of German mathematicians to find and correct the many mathematical errors in the works of David Hilbert, so that they could be collected into a volume to be presented to Hilbert on his birthday, and that there was only one paper (on the continuum hypothesis) which Taussky-Todd was unable to repair?