The impact of extraterrestrial matter onto Earth is a continuous process. On average, some 50,000 tons of dust are delivered to our planet every year. While objects smaller than about 30 m mainly disintegrate in the Earth’s atmosphere, larger ones can penetrate through it and cause damage on the ground. When an object of hundreds of meters in diameter impacts an ocean, a tsunami is created that can devastate coastal cities. Further, if a km-sized object hit the Earth it would cause a global catastrophe due to the tran...

The impact of extraterrestrial matter onto Earth is a continuous process. On average, some 50,000 tons of dust are delivered to our planet every year. While objects smaller than about 30 m mainly disintegrate in the Earth’s atmosphere, larger ones can penetrate through it and cause damage on the ground. When an object of hundreds of meters in diameter impacts an ocean, a tsunami is created that can devastate coastal cities. Further, if a km-sized object hit the Earth it would cause a global catastrophe due to the transport of enormous amounts of dust and vapour into the atmosphere resulting in a change in the Earth’s climate.

a) the kinetic energy is given by 1/2 mv2
Assuming mass of 100 meter diameter asteroid as 100 million MT = 10^8 kg
E = 1/2 x 10^8 x 13000 x 13000 = 8.45 x 10^14 joules = 8.45 x 10^6 GJ

b) If 1 Ton of TNT releases 4.184 GJ then the above energy will be equivalent to approximately 2 million Ton of TNT.

c) This is equivalent to energy 2/60 or 1/30th of the largest nuclear weapon ever tested on earth. I would advice you to read this article on website with picture and compare your self the devastation it would create on earth.

http://www.hartrao.ac.za/other...