LAUREL, Md. — The science team for NASA’s New Horizon spacecraft released its first multi-pixel view of an icy world more than 4 billion miles from Earth, and the analysis suggests it’s an elongated space cigar.
“We know it’s not round, we can say that with confidence,” John Spencer of the Southwest Research Institute, one of the mission’s project scientists, said today during a news briefing scheduled just hours before the probe was due to fly just 2,200 miles past the mysterious object.
Based on observations made on Earth during stellar occultations, Spencer and other astronomers suspected that the object — known by its formal designation, 2014 MU69, or by its nickname, Ultima Thule — might be made of smooshed-together chunks of ice and rock.
Spencer said the fuzzy image was still consistent with that hypothesis, but scientists will know definitively once better-quality pictures are sent back from the close encounter, which is set to occur at 12:33 a.m. ET on New Year’s Day (9:33 p.m. PT tonight).
Those pictures won’t be released until later in the week, but even the fuzzy pre-flyby image energized the New Horizons team, said SwRI’s Alan Stern, principal investigator for the mission.
“I’ve never seen so many people excited about two pixels,” Stern quipped.
The image was captured at 11:56 a.m. ET on Sunday, when the probe was still 1.2 million miles away from Ultima Thule (“Ul-ti-ma Too-lee”), which is within an icy region of the solar system known as the Kuiper Belt.
Three and a half years ago, the piano-sized New Horizons probe flew past Pluto, which is on the near edge of the Kuiper Belt, at a distance of more than 3 billion miles. After the Pluto reconnaissance mission was concluded, NASA authorized New Horizons to take on an extended mission to study Ultima Thule, which was identified using Hubble Space Telescope imagery during the probe’s cruise toward Pluto.
The Ultima Thule phase of the mission represents history’s farthest-out encounter with a celestial body, and the first up-close study of a type of mini-world known as a “cold classical” Kuiper Belt object. Cold classicals are thought to rank among the solar system’s most primitive objects, and New Horizons’ encounter could shed more light on the process that led to planetary formation.
“The Kuiper Belt is a scientific wonderland,” Stern said.
Several gigabytes’ worth of imagery and data from the flyby will be stored in New Horizons’ solid-state memory banks, and transmitted back to Earth over the course of 20 months.