NASA’s Near-Earth observatory (NEO) is monitoring an asteroid bigger than New York’s Empire State building that is expected to pass by the Earth Saturday.According to the NEO, the asteroid known as 2002 NN4 at its broadest section, has a diameter of 570 meters. The Empire State building is just more than 426 meters tall.  But scientists at the NEO say there is nothing to fear from the asteroid, as “near earth” is a relative term. They measure the distance to deep space objects in astronomical units, with one astronomical unit close to the mean distance between the sun and Earth – approximately 150 million kilometers. Anything that comes within 1.3 astronomical units of the sun, is considered a near-Earth objectAt its closest distance, Asteroid 2002 NN4 is expected to pass about .034 astronomical units – or about 5.09 million kilometers from Earth, about 13 times the distance between the Earth and the moon.  NASA established the Near-Earth Object Observations Program in 1998 to monitor such objects. They say relatively small number of near-Earth objects pass close enough to Earth and are large enough in size to warrant close observation. They say the gravitational tug of the planets could, over time, cause an object’s orbital path to evolve into an Earth-crossing orbit, creating the possibility of a future collision.NASA says it has contingency plans for such an event. But in a recent discussion posted on the space agency’s website. NASA Director of Planetary Science, Dr. Lori Glaze, said the possibility does not keep her up at night.
 
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