Asteroid Apophis- A threat to Earth??

 

In one of our earlier issues (Astrobiology Volume 12, No 3)  we had mentioned about asteroid Apophis passing earth on 29^th April 2029,  within a distance of 30000km that has several geosynchronous and other satellites orbiting Earth. We had also mentioned that in 2029 the asteroid may pass earth without much damage but the later transit may cause huge destruction on earth. Recently astronomer David Tholen from the University of Hawaii after observing the asteroid presented his and his colleague Davide Farnocchia's research showing that there are minute chances - roughly one in 530,000 - the asteroid Apophis could hit Earth in 2068 April transit. Through their study, they were able to detect the Yarkovsky effect on the asteroid. The Yarkovsky effect is the acceleration produced or sudden push changing the orbit of the asteroid due to asymmetrical heating of asteroid facing the sun and the shadow region. Now with detecting the Yarkovsky effect on the asteroid,  the scientists are looking forward to the 2029 transit of Apophis near the Earth so that they can study the physical nature and dynamics of the asteroid in detail. This 27 billion kilogram Asteroid striking Earth (if at all in 2068) would leave a crater more than a kilometer wide and 518-meter depth with an impact that would be equivalent to 880million tons of TNT being detonated – 65,000 times as powerful as the nuclear bomb which was dropped on Hiroshima.