Annihilation of Jews in Kharkiv, Ukraine: in the proximity of the Rogan works, 8 km away from Kharkiv, in "Drobitsky Ravine" (Drobitsky Yar), over 15 000 Jews were shot, at-15 degrees C below zero.,

The 43rd known Mersenne prime is discovered by Dr. Curtis Cooper & Dr. Steven Boone of United States, participants of the Great Internet Mersenne Prime Searchdistributed computing project. The prime number is 2nd largest known prime and has more than nine milliondigits.,