MOST DISTANT PLACE WE’VE VISITED.
LAUREL, MD .• NASA’S New Horizons spacecraft has survived the most distant exploration of another world, a tiny, icy object six billion kilometres away that looks to be shaped like a peanut or bowling pin.
Word of success came 10 hours after the middle-ofthe-night encounter, once flight controllers in Maryland received word from the spacecraft late Tuesday morning. Cheers erupted at Johns Hopkins University’s Applied Physics Laboratory, home to Mission Control, as mission operations manager Alice Bowman declared: “We have a healthy spacecraft.”
A huge crowd in a nearby auditorium joined in the loud celebration, cheering each status update. Scientists and team members embraced, while hundreds of others gave a standing ovation. “I don’t know about all of you, but I’m really liking this 2019 thing so far,” lead scientist Alan Stern of Southwest Research Institute said to applause. “I’m here to tell you that last night, overnight, the United States spacecraft New Horizons conducted the farthest exploration in the history of humankind, and did so spectacularly.”
New Horizons zoomed past the small celestial object nicknamed Ultima Thule 31/2 years after its spectacular brush with Pluto. Scientists said it will take nearly two years for New Horizons to beam back all its observations of Ultima Thule, a full 1.6 billion kilometres beyond Pluto. At that distance, it takes six hours for the radio signals to reach Earth.
Scientists did not want to interrupt observations as New Horizons swept past Ultima Thule — described as a bullet intersecting with another bullet — so they delayed radio transmissions. The spacecraft is believed to have come within 3,500 kilometres of Ultima Thule. New Horizons’ 2015 encounter with Pluto was the most distant exploration until Tuesday. The Ultima Thule rendezvous was more complicated, given its 6.4 billion-kilometre distance from Earth, the much closer gap between the spacecraft and its target, and all the unknowns.
Based on rudimentary pictures snapped just hundreds of thousands of kilometres before the 12:33 a.m. close approach, Ultima Thule is decidedly elongated — about 35 km by 15 km. Scientists say 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. An answer should be forthcoming Wednesday, once new and better pictures arrive.
The icy rock has been in a deep-freeze preservation state since the formation of our solar system 4.5 billion years ago. Scientists hope to learn about those origins through New Horizons’ observations deep inside the so-called Kuiper Belt on the fringes of the solar system.