“A massive piece of rock hit the Earth 65 million years ago, which set off the events that wiped out the dinosaurs” (R. Cowen, 2007). This rock that killed off the dinosaurs could have been an asteroid or comet. “In 1980, Alvarez and colleagues proposed that, in the transition period between the Cretaceous to Paleogene periods, a large impactor collided with the Earth being the cause of the mass extinction occurred at the K/Pg boundary.” (Hector Javier Durand-Manterola et al., 2014). The K/Pg boundary stands for Cretaceous and Paleogene periods. “In 1991, an international group of researchers proposed that a circular structure between 180 and 200 km, buried under the Tertiary deposits in the Yucatan Peninsula in Mexico, was the crater formed …show more content…
Moore and Sharma say, “We are proposing a comet because that conclusion hits a ‘sweet spot.’ With comets having lower levels of iridium and osmium than asteroids, yet with a high-velocity comet would have sufficient energy to create a 177-km-wide crater. Asteroids move much slower than comets, so comets have more energy on impact, which in combination with their partially ice make up means they don’t contribute more iridium and osmium.” (Science Teacher, 2013). “In synthesizing the data generated by two very disparate fields of research—geochemistry and geophysics—we are 99.9% sure,” Sharma said, “that what we are dealing with is not an asteroid but a comet impact.” (Science Teacher, 2013). With comets having mostly ice bodies it would make sense that it would have a lower level of metals and other elements. Hector Javier Durand-Manterola and Guadalupe Cordero-Tercero found, “Kinetic energy of the impactor is in the range from 1.3x10^24 J to 5.8x10^25 J. The mass is in the range of 1.0x10^15 kg to 4.6x10^17 kg. The diameter of the impactor is in the range of 10.6 km to 80.9 km.” (Hector Javier Durand-Manterola et al., 2014). “When compared with measurements, we concluded that the estimation is that of a comet was the impactor that made the Chicxulub carter.” (Hector Javier Durand-Manterola et al., 2014). With those measurements it is plausible that it was a fast decent size comet. “The size and depth of the crater, plus the distribution of ejecta, suggest that a comet was moving at 180,000 km/hr, and that Earth ran right into the comet.” (Wayne Campbell, 1992). With an object moving that fast it could do some serious damage to the surface of the Earth. “When the comet struck it was particularly catastrophic because it struck a continental shelf. Carbon dioxide levels jumped 10x the normal amount and this was from seabed limestone vaporizing.” (Wayne Campbell, 1992). “Alan Hildebrand says,