Torino scale the validity and societal impact of SETI data. The Torino Scale also uses a color code scale: white, green, yellow, orange, red. Each color code has an overall meaning: No object has ever been rated above level 4. The Chicxulub impact, believed by most scientists to be a significant factor in the extinction of the dinosaurs, has been estimated at 100 million (10) megatons, or Torino Scale 10. The impacts which created the Barringer Crater and the Tunguska event in 1908 are both estimated to be in the 3–10 megaton range, corresponding to Torino Scale 8. The 2013 Chelyabinsk meteor
Judo in Canada (2011), Raymond Damblant (2012), and Hiroshi Nakamura (2012). Eleven Canadians are ranked "hachidan" (eighth dan), twenty-seven are ranked "shichidan" (seventh dan), and approximately 85 others are ranked "rokudan" (sixth dan). The names of the ninth and eighth "dan" holders are listed in the tables to the right. A typographic dagger () follows the names of those who are deceased. A registry of approximately 5000 black belts ranked "shodan" (first "dan") to "hachidan" (eighth "dan") in the years 1946–1997 is included in Glynn Leyshon's book "Judoka: a history of Judo in Canada". Canadians have won five Olympic medals in Judo since