- Video report by ITV News Correspondent Richard Pallot
A Nasa spacecraft has made contact with Earth after surviving humanity's most distant exploration of another world.
Earlier on Tuesday, the New Horizons spacecraft completed a flyby of Ultima Thule - an icy object four billion miles (6.5 billion km) away.
Ten hours after the middle-of-the-night encounter, flight controllers in Laurel, Maryland, received word from the spacecraft that it had successfully completed its latest mission, passing within 2,200 miles (3,500km) of Ultima Thule.
The radio message from the robotic craft which is the size of a baby grand piano, was picked up by one of Nasa's big antennas, in Madrid, Spain.
"We have a healthy spacecraft," announced Mission Operations Manager Alice Bowman.
"We've just accomplished the most distant flyby."
Cheers erupted at Johns Hopkins University's Applied Physics Laboratory, home to mission control.
An anxious crowd in a nearby auditorium watching events joined in the loud celebration following the success of the £628 million mission.
New Horizons zoomed past the small celestial object known as Ultima Thule three-and-a-half years after its spectacular brush with Pluto in which it discovered dunes on the dwarf planet made of tiny frozen grains of methane.
One of the first images snapped just hundreds of thousands of miles before the 12.33am close approach, Ultima Thule is elongated in shape - measuring about 22 miles (35.4km) by nine miles (14.5km).
Scientists say there are two possibilities for this: Ultima Thule is either one object with two connected lobes, sort of like a spinning bowling pin or peanut still in the shell, or two objects orbiting surprisingly close to one another.
A single body is more likely, they noted.
Scientists say it will take nearly two years for New Horizons to beam back all its observations and photos of Ultima Thule, a full billion miles beyond Pluto.
At that distance, it takes six hours for the radio signals to reach Earth, and coupled with the probe's small, 15-watt transmitter, mean data rates are incredibly slow, topping out at one kilobit per second.
Due to the time-lag and slow data rate, it is hoped that colour close-up images of Ultima Thule will be available on Wednesday at the earliest, shedding more light on the shape of the planet.
Ultima Thule is in the Kuiper belt, or frozen Twilight Zone - a band of frozen material that orbits the Sun more than 1.24 billion miles (2 billion km) further out than the eighth of the classical planets, Neptune; and 932 million miles (1.5 billion km) beyond Pluto on the fringes of the Solar System.
It is estimated that there are hundreds of thousands of other objects like Ultima Thule in the Kuiper belt, and it is hoped that their frigid state holds clues to the formation conditions of the Solar System 4.6 billion years ago.
New Horizons is not stopping at Ultima Thule and will continue to zoom farther away, with the hope is that the mission will be extended yet again and another target will be forthcoming sometime in the 2020s.
Ultima Thule is the first destination to be reached that was not even known until after the spacecraft's launch.
New Horizons rocketed from Cape Canaveral, Florida, in 2006.