To the Sun

NASA has visited some awfully impressive places in the past 60 years, so it's something of a wonder that the space agency hasn't found its way to the sun by now. The New Horizons probe, which flew by Pluto in the summer of 2015, is now 3.5 billion miles (5.6 billion km) away; Voyager 1, launched in 1977, has left the solar system entirely, cruising through space at a remove of 11.7 billion miles (18.9 billion km) from Earth.