NASA's New Horizon probe is getting closer to the dwarf planet at about 52,000 km per hour. The probe will fly past Pluto and come within 12,550km of Pluto's surface during its closest approach on July 14. Its cameras and instruments will gobble data, at 11.49pm (New Zealand time).

The instruments and the antennae on the probe are configured in such a manner that New Horizons cannot observe Pluto and simultaneously transmit data to Earth. A one-way message to or from New Horizons requires a 4.5- hour trip even at the speed of light (299,792,458 metres per second).

Scientists will begin a countdown to the flyby, and celebrate at 11.49pm (7.49am local time) on July 14. However, they won't know until late that evening whether the spacecraft survived the encounter. They'll get a simple batch of data at about 1pm Wednesday.

Pluto is so far away (5.8 billion kms) and about two-thirds the size of our moon). In Hubble images, Pluto has always been a tiny, pixelated blob.

The headquarters of the New Horizons mission is the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. New Horizons was launched into space in 2006 atop an Atlas V rocket and many people at APL have been with New Horizons since its launch.

Mission operations manager Alice Bowman said, "We know this spacecraft very well. It's our baby. It went through its toddler stage where it was a little ornery".

Scientists believe that the probe will provide insights into the origin and evolution of the solar system. The spaceship's long-range camera has already detected intriguing patterns on the surface of Pluto.