In color and composition, Ultima Thule is very red, even redder than the much larger, 2,80-km-wide Pluto, which New Horizons explored at the inner edge of the Kuiper Belt in 2015.
Data transmission from the flyby continues, and will go on until the late summer 2020. In the meantime, New Horizons continues to carry out new observations of additional Kuiper Belt objects it passes in the distance, according to the mission team.
"We're looking into the well-preserved remnants of the ancient past," said New Horizons Principal Investigator Alan Stern. "There is no doubt that the discoveries made about Ultima Thule are going to advance theories of solar system formation."
LOS ANGELES, May 17 (Xinhua) -- The National Aeronautics and Space Administration's (NASA) New Horizons mission team has published the first profile of the Kuiper Belt object (KBO) nicknamed "Ultima Thule," the most distant object ever explored by mankind.
Ultima Thule is in fact the reddest outer solar system object ever visited by spacecraft, according to the scientific results. Its reddish hue is believed to be caused by modification of the organic materials on its surface.
How the two lobes got their unusual shape is an unanticipated mystery that likely relates to how they formed billions of years ago, according to the scientific results.
The initial data revealed the object's development, geology and composition. The 36-km-long Ultima Thule is a contact binary, consisting of a large, strangely flat lobe (nicknamed "Ultima") connected to a smaller, rounder lobe (nicknamed "Thule"), at a juncture nicknamed "the neck."
New Horizons researchers are also investigating a range of surface features on Ultima Thule, such as bright spots and patches, hills and troughs, and craters and pits.
New Horizons performed the farthest flyby in history at 12:33 a.m. EST (0533 GMT) on Jan. 1 this year, as it approached Ultima Thule within 2,80 miles (about 3,540 km) of the surface at a velocity of 31,800 miles (about 80,694 km) per hour.
The New Horizons spacecraft is now 4.1 billion miles (6.6 billion km) from Earth, operating normally and speeding deeper into the Kuiper Belt at nearly 33,000 miles (53,000 km) per hour, according to the team.
The mission team published the first peer-reviewed scientific results and interpretations in the May 17 issue of the journal Science, analyzing the first sets of data gathered during the flyby.