Pluto journey marks ‘human history’

New Horizons, the fastest spacecraft ever flown, made history yesterday as it shot past Pluto at more than 48,280kph, taking pictures and collecting scientific data.

During the fly-by, the first close encounter with Pluto ever achieved, the American probe passed within 12,500km of the mysterious world.

At the Applied Physics Laboratory at Johns Hopkins University in Maryland, mission control staff and visitors clapped, cheered and waved American flags, chanting “USA, USA” in an outpouring of patriotic emotion.

The spacecraft was due to make its closest approach to Pluto at 12.49pm.

All the indications are that the fly-by has been a success, but the New Horizons team will not know for sure until the probe contacts Earth again at 1.53am today.

Earlier the American space agency Nasa posted a stunning new image of Pluto on Instagram, taken by New Horizons from 766,000km.

It clearly shows the dwarf planet’s surprising Mars-like reddish hue, and the enigmatic heart-shaped feature on its surface that has already become Pluto’s calling card on the internet.

Other photos taken from a million miles away revealed evidence of cliffs, craters, and chasms larger than the Earth’s Grand Canyon.

Speaking at APL, former astronaut John Grunsfeld, associate administrator of Nasa’s Science Mission Directorate, said: “It’s just amazing. This is truly a landmark in human history.

“People often think the success of missions like this is about engineers, the hardware, but the real key is teamwork, and that’s what Nasa excels at.

“We’re celebrating the moment New Horizons had its closest approach to Pluto, but we’re not talking to the spacecraft; it’s doing its job. Tonight we’re going to get the signal, the ping, telling us that it made it through the system and it’s ready to start sending us a treasure trove of data.”

New Horizons has taken more than nine years to reach Pluto, carrying with it the ashes of the astronomer who discovered the remote icy object in 1930.

When the mission was launched in January 2006, the aim was to reach the outermost of the Sun’s family of nine planets. Seven months into the probe’s epic journey, international astronomers downgraded Pluto’s status to “dwarf planet”.

However. despite its small size — just over two thirds the diameter of the Earth’s moon — Pluto looks and behaves like a fully fledged planet, having an atmosphere and no less than five moons of its own.

Pluto is about 4.8bn kilometres from Earth, a distant ‘worldlet’ in the Kuiper Belt. It is so far away that its light takes more than four hours to reach Earth, making communication with New Horizons an exercise in patience.

New Horizons has already answered one basic question about Pluto, its precise size. Scientists used photos from the spacecraft’s telescopic camera, the long range reconnaissance imager, to determine that the dwarf planet is somewhat larger than previously thought, having a diameter of 2,370km.