New Horizons zips past Pluto in the early hours of the morning U.S. time tomorrow:
Last night at 11:23 p.m. EDT (this morning at 4:23 a.m. BST), New Horizons moved within one million miles (1.6 million kilometers) of Pluto, speeding towards the dwarf planet and its five moons at 30,800 mph (49,600 km/h). It will arrive tomorrow at 7:49 a.m. EDT (12:49 pm BST), although owing to the vast distances involved and a one-way communications time of 4.5 hours, we won’t know if it has been successful until the end of the day. The first signals and data are expected back at 8:53 p.m. EDT Tuesday (1:53 a.m. BST Wednesday).
Despite the long journey time, the flyby will last just over two hours. The best images can be expected on Wednesday, but it will take 16 months for all of the data taken by the spacecraft to be sent back to Earth. This is due to both the distance and the low bit rate of the spacecraft, which has the ashes of its discoverer Clyde Tombaugh on board.
The spacecraft is the fastest-moving human-made object in the universe. This is how it got to Pluto in only 9 years, with the trade-off that its visit will be so short.