Moon : Asteroid Apophis flew by every seven years and was much larger than expected . Named after an evil Egyptian serpent god , Apophis swings by this month . Bear : We can never be 100 % sure how close it will come or if events might change its course . What could change between now and 2029 , or during any orbit thereafter ? If Apophis hit Earth , he says , the blast would be the equivalent of over more than 20 million tons of the Barringer Crater .
Moon : Asteroid Apophis flew by every seven years and was much larger than expected . Named after an evil Egyptian serpent god , Apophis swings by this month . Bear : We can never be 100 % sure how close it will come or if events might change its course . If Apophis hit Earth , he says , the blast would be the equivalent of over more than 20 million tons of the Barringer Crater .