New Horizons is the first NASA mission designed specifically to explore the outer solar system — a region that Stern calls “a scientific wonderland.” Out in the Kuiper belt, where sunlight is 0.05 percent as strong as it is on Earth and temperatures hover near absolute zero, the primitive building blocks of planets have persisted unchanged for 4.6 billion years.
“This is history-making, what we’re doing, in more ways than one,” Stern said. Every image sent back from New Horizons is the most distant photograph ever taken. Each maneuver is further than anything NASA has done before.
Ultima Thule is also among the most primitive objects ever explored. Unlike planets, which are transformed by geologic forces in their interiors, and asteroids, which are heated by the sun, Ultima Thule is thought to have existed in a “deep freeze" since it first formed.
“It is probably the best time capsule we’ve ever had for understanding the birth of our solar system and the planets in it,” Stern said.