Triumph for Nasa at edge of solar system
A Nasa probe has reached the furthest cosmic object ever explored by humankind, revealing new clues to how the planets formed. Ultima Thule, a space rock 22 miles long and nine miles wide, sits in the Kuiper belt, four billion miles from Earth, on the edge of the known solar system. The New Horizons probe flew by at 32,000mph, passing within 2,200 miles of the surface. From there, it took 10 hours for an anxiously awaited “phone home” signal to reach mission control.
A NASA probe has reached the furthest cosmic object ever explored by humankind, revealing new clues to how the planets formed.
Ultima Thule, a space rock 22 miles long and nine miles wide, sits in the dark and frigid Kuiper belt, four billion miles from Earth, on the edge of the known solar system.
The New Horizons probe flew by at 32,000mph, passing within 2,200 miles of the surface.
From there, it took 10 hours for an anxiously awaited “phone home” signal to reach mission control at Johns Hopkins University Applied Physics Laboratory in Maryland.
As cheers erupted, Alice Bowman, the mission operations manager, said: “We have a healthy spacecraft. We’ve just accomplished the most distant flyby. This science will help us understand the origins of our solar system.”
A blurry initial image sent back of Ultima Thule showed a white object resembling a bowling pin, or a peanut, and rotating like a propeller.
The fly-by was more than a billion miles beyond Pluto, previously the furthest space object ever visited.
Scientists hope fresh images of Ultima Thule will help them learn about the ancient building blocks of planets.
Along with other bodies in the Kuiper belt, it is a relic from the early solar system, having been deeply frozen and perfectly preserved. It takes 295 years to orbit the Sun.
Seven instruments on the New Horizons will be used to detect the chemical composition of its atmosphere and terrain. Beaming all the discoveries back will take two years.
Alan Stern, the lead planetary scientist for New Horizons, said: “Everything we are going to learn, from its composition to its geology, to how it was originally assembled, whether it has satellites and an atmosphere and those kinds of things, are going to teach us about the original formation conditions of objects in the solar system.”
He said the initial picture looked like a “pixelated blob” but better images would arrive. He added: “The data we have looks fantastic, and we’re already learning about Ultima from up close. From here out, the data will just get better and better.”
Scientists are still unsure, until they see further images, if the object is a single body, or two orbiting each other.
Ultima Thule was discovered in 2014 with the help of the Hubble Space Telescope. It was originally called 2014 MU69, but renamed after Thule, a mythical island in medieval literature.
The space agency said “Ultima Thule” meant “beyond Thule” and was intended to indicate “beyond the borders of the known world”.
New Horizons launched in 2006 with the stated mission of flying by Pluto. It reached the dwarf planet in 2015, revealing methane-rich dunes on the surface. The probe was then redirected to Ultima Thule.
While it has conducted the most distant close encounter with a space object, New Horizons is not the most distant probe from Earth. Voyager 1 and Voyager 2, launched in 1977, both reached greater distances.
Brian May, the Queen guitarist, who has a PHD in astrophysics, is a participating scientist in the New Horizons mission. He also wrote a song in honour of the probe.
After the fly-by, he said: “This is a night none of us are going to forget. This mission represents to me the spirit of adventure, discovery and inquiry which is inherent in the human spirit.”
As those of us here on Earth greeted the start of a new year, four billion miles away Nasa’s New Horizons probe was exploring new depths of space. The probe’s successful visit to Ultima Thule, a frozen mass that now has the distinction of being the most distant object ever visited by a spacecraft, is a glorious – and welcome – reminder of what mankind is capable of achieving. This July marks 50 years since man first walked on the Moon, but while most “giant leaps” are now carried out by robots, the idea of the final frontier being pushed ever further back continues to thrill. Long may it continue.