Just after midnight on New Year’s Eve, NASA set a precedent in the exploration of our solar system. At 12:33 a.m., the New Horizons spacecraft drifted through the Kuiper Belt and snapped the first images of Ultima Thule, an icy, rocky mass outside the orbit of Neptune. At 4.1 billion miles away from Earth (and 1 billion miles past Pluto), Ultima Thule is the farthest object ever photographed by a spacecraft.
The first image relayed to Earth that morning was a low-resolution blur (you can count the pixels) likened to a bowling pin. A few days later, enhanced-color and stereoscopic imagery revealed Ultima Thule’s shape and rough topography. It appears to have been formed by the gradual merging of two separate, spherical masses called “planetesimals.” In photos, the mass is comparable to a dimpled snowman.
This frozen blob, just 21 miles wide, may prove revolutionary to human understanding of planetary science. Because of its particular location, Ultima Thule avoided the chaos and collisions that created Earth and the inner solar system’s other planets. And at a temperature of 400 degrees below zero Fahrenheit, its original composition is neatly preserved, making Ultima Thule a possible undisturbed relic from the solar system’s early years. Its orbit and color reinforce this possibility, making it especially interesting to scientists seeking insights about the formation and evolution of planets. New Horizons is thusly equipped with advanced cameras to inspect the object’s surface features and geology, as well as spectrometers to measure reflected infrared waves and to detect different types of ice.
With a mere 15-watt transmitter and a download rate of 500 bits per second, these insights will trickle in slowly. Thanks to a prioritization effort by the New Horizons team, the most telling data will arrive as soon as February or early March. But it will take approximately 20 months to transmit the entire dataset. The process may be lengthy, but the ability to capture and transmit data so far from Earth’s orbit redefines the parameters of modern space exploration.
This breakthrough doesn’t mark the end of the mission for New Horizons—it extends it. Even after a six-month flyby study of Pluto, a pit stop at Jupiter, and the Ultima Thule maneuver, the spacecraft holds enough fuel to operate through the next decade barring setbacks. After studying the Ultima Thule data, the New Horizons team will likely attempt more discoveries even farther into the great unknown.
Photo Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute