Ultima Thule
NASA has found evidence for a unique mixture of methanol, water ice, and organic molecules on Ultima Thule's surface -- the farthest world ever explored by mankind.
The US space agency has published the first profile of Ultima Thule -- an ancient relic from the era of planet formation -- revealing details about the complex space object.
Analysing just the first sets of data gathered during the New Horizons spacecraft's New Year's 2019 flyby of the Kuiper Belt object 2014 MU69 -- nicknamed Ultima Thule -- unveil much about the object's development, geology and composition.
Researchers are also investigating a range of surface features such as bright spots and patches, hills and troughs, and craters and pits on Ultima Thule.
The largest depression is a 8-kilometer-wide feature the team has nicknamed Maryland crater -- which likely formed from an impact.
Some smaller pits on the Kuiper Belt object, however, may have been created by material falling into underground spaces, or due to exotic ices going from a solid to a gas and leaving pits in its place.
In colour and composition, Ultima Thule resembles many other objects found in its area of the Kuiper Belt. Its reddish hue is believed to be caused by modification of the organic materials on its surface.
According to the research published in the journal Science, the team found evidence for methanol, water ice, and organic molecules on Ultima Thule's surface -- a mixture very different from most icy objects explored previously by spacecraft.
"We're looking into the well-preserved remnants of the ancient past," said Alan Stern of the Southwest Research Institute, Boulder, Colorado.
"There is no doubt that the discoveries made about Ultima Thule are going to advance theories of solar system formation," said Stern, Principal Investigator of the New Horizons mission.
Ultima Thule is a contact binary, with two distinctly differently shaped lobes, NASA said.
At about 36 kilometers long, Ultima Thule consists of a large, strangely flat lobe -- nicknamed "Ultima" -- connected to a smaller, somewhat rounder lobe -- dubbed "Thule" -- at a juncture.
How the two lobes got their unusual shape is an unanticipated mystery that likely relates to how they formed billions of years ago, NASA said in a statement.
The lobes likely once orbited each other until some process brought them together in what scientists have shown to be a "gentle" merger.
For that to happen, much of the binary's orbital momentum must have dissipated for the objects to come together, but scientists do not yet know whether that was due to aerodynamic forces from gas in the ancient solar nebula, or if Ultima and Thule ejected other lobes that formed with them to dissipate energy and shrink their orbit.
The alignment of the axes of Ultima and Thule indicates that before the merger the two lobes must have become tidally locked, meaning that the same sides always faced each other as they orbited around the same point.
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.
The New Horizons spacecraft is now 6.6 billion kilometers from Earth, operating normally and speeding deeper into the Kuiper Belt at nearly 53,000 kilometers per hour.
