On July 14, an epic once-in-a-lifetime event will take place: NASA will fly their spacecraft, New Horizons, by Pluto.

A NASA spacecraft set to encounter Pluto this summer has spotted two small moons orbiting the icy dwarf planet.

Closing in on Pluto at about 49,890 kph, New Horizons already has covered more than 3 billion miles since it launched on January 19, 2006.