According to Business Insider, NASA's New Horizons spacecraft completed its second flyby mission of a distant celestial body.<br />After passing by Pluto and its five moons back in 2015, New Horizons is now in the Kuiper Belt, which is near Neptune.<br />But the space probe had a date with a specific rocky body in the belt.<br />Known as Ultima Thule, the 20-mile long object is now the most distant object humanity has ever explored. <br />
