NASA spaceship closes in on distant world

NASA's unmanned New Horizons spacecraft is closing in on its historic New Year's flyby target, the most distant world ever studied, a frozen relic of the solar system some four billion miles (6.4 billion kilometers) away.The cosmic object, known as Ultima Thule, is about the size of the US capital, Washington, and orbits in the dark and frigid Kuiper Belt about a billion miles beyond the dwarf planet, Pluto."This is a time capsule that is going to take us back four and a half billion years to th