NASA's New Horizon Mission Team has released the first longest-running world profile ever explored, a planetary block and Kuiper Belt object called 2014 MU69.
Just analyzing the first sets of data collected during New Horizon's spacecraft's new year 2019 flyby of MU69 (nicknamed Ultima Thule), the mission group quickly discovered an object that is much more complex than expected. The team publishes the first peer-reviewed scientific results and interpretations – just four months after the flyby – in May 17 issue of the journal Science.
In addition to being the longest exploration of an object in history – four billion miles from the earth – Ultima Thule's flyby was also the first survey of any space mission by a well-preserved planeteseimal, an ancient planet formation era relic.
The original data summarized in Science reveals much about the object's development, geology and composition. It is a contact binary, with two distinctly different shaped lobes. Ultima Thule consists of a large, strange flat lobe (nicknamed "Ultima") in about 22 miles (36 kilometers), which is connected to a smaller, somewhat rounder leg (nicknamed "Thule"), at a moment named "the neck". How the two lobes have their unusual shape is an undiscovered mystery that probably relates to how they formed billions of years ago.
The lobe probably once twisted each other, as did many so-called binary worlds in the Kuiper belt, until some process took them together in which researchers have proven to be a "mild" merger. In order for this to happen, much of the binary momentum must have disappeared for the objects to come together, but researchers do not know whether it was due to aerodynamic forces from gas in the old sunbeam or whether Ultima and Thule were ejected other lobes formed with them in order to release energy and reduce its circulation. The adjustment of the axes in Ultima and Thule indicates that the two lobes prior to the fusion must have been locked early, which means that the same sides always meet each other when they orbit the same point.
"We are looking at the well-preserved remains of the ancient past," said New Horizon's lead researcher Alan Stern, Southwest Research Institute, Boulder, Colorado. "There is no doubt that the discovery of Ultima Thule will develop theories of solar system formation."
Like the scientific paper reports, New Horizon's researchers are also examining a number of surface features on Ultima Thule, such as light spots and spots, hills and troughs and craters and pits at Ultima Thule. The biggest depression is a 5 kilometer wide (8 kilometer wide) feature that the team has nicknamed Maryland crater – which is likely to be formed by an impact. However, some smaller pits on the Kuiper Belt object may have been created by the material falling into underground spaces or due to exotic ices going from a solid to a gas (called sublimation) and leaving pits in place.
In color and composition, Ultima Thule is similar to many other objects found in its area of the Kuiper belt. It is very red – also saves much larger, 1500 kilometers (2400 kilometers) wide Pluto, which New Horizons explored at the Kuiper Belt's inner edge in 2015 – and is in fact the redest outer solar system object ever visited by spacecraft; its reddish hue is believed to be caused by the change of the organic material on its surface. New Horizon researchers found evidence of methanol, water ice and organic molecules on the Ultima Thule surface – a mixture that is very different from most icy objects previously explored by spacecraft.
Data transmission from the flyby continues and continues until the end of summer 2020. Meanwhile, New Horizons continues to make new observations of additional Kuiper Belt objects passing in the distance. These additional KBOs are too long to reveal discoveries like those on MU69, but the team can measure aspects such as the brightness of the object. New Horizons also continues to chart charged particle radiation and dust environment in the Kuiper belt.
New Horizon's spacecraft is now 4.1 billion miles from Earth, which normally works and deeper into the Kuiper Belt of nearly 33,000 miles (53,000 miles) per hour.
Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, designed, built and operated New Horizon's spacecraft and manages the mission of NASA's Science Mission Directorate. MSFC Planetary Management Office provides NASA monitoring for New Horizons. The Southwest Research Institute, based in San Antonio, manages the mission through Stern's lead researcher, leading the science team, payload operations, and meeting science planning. New Horizons is part of the New Frontiers program managed by NASA's Marshall Space Flight Center in Huntsville, Alabama.
Publication: S. A. Stern, et al., "Initial results from New Horizon's 2014 MU exploration69, a small Kuiper belt object, "Science 17 May 2019: Vol. 364, edition 6441, eaaw9771; DOI: 10.1126 / science.aaw9771