A NASA probe which was the first spacecraft to explore Pluto is continuing its journey out into the solar system, where it is now almost 5 billion miles from home. New Horizons was launched in 2006 and traveled out to the edge of the solar system. On its way, it captured a close-up image of Pluto and visited the farthest object humanity has reached . Now, it has passed a big milestone, reaching 50 astronomical units from the sun. An astronomical unit, or AU, is a measurement of distance that is equivalent to the average distance between the sun and the Earth. So New Horizons is now 50 times further away from the sun than the Earth is. This massive distance means it takes longer and longer for signals from New Horizons to reach Earth, resulting in an increasing communication delay. “It’s hard to imagine something so far away,” said Alice Bowman, the New Horizons mission operations manager at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, in a statement . … [Read more...] about New Horizons is now 50 times as far from the sun as Earth