Pluto Probe Yields New Discoveries

Arrokoth (2014 MU69) | Image by NASA

A space probe has made new discoveries about the dwarf planet Pluto.

NASA’s New Horizons probe has made three new discoveries about the former planet and a Kuiper Belt object. These findings were detailed at the Lunar and Planetary Science Conference (LPSC) last week.

The New Horizons probe was launched in January 2006 and was the first spacecraft to approach Pluto. The craft flew by Pluto and its moon in July 2015 after its more than nine-year voyage through space, passing 7,800 miles above the dwarf planet’s surface.

The probe passed by its secondary target, the snowman-shaped Kuiper Belt object Arrokoth, in 2019. Arrokoth is the most distant object ever observed up close in space.

The first of the discoveries attributes the dwarf planet’s orientation to one of its ice basins. Researchers postulated that the current orientation of the planet was caused by the formation of the 620-mile-wide basin on the surface known as Sputnik Planitia.

Scientists suggest that the basin played a part in the planet’s polar reorientation. The celestial body’s subsurface ocean is also theorized to have played a role in that it shifted the planet’s mass to the equator.

Images sent by the probe during its initial flyby of parallel mountain ranges and deep valleys suggest the presence of the planet’s global tectonic system. Using this data, researchers attempted to trace the planet’s supposed “flip” and documented that surface features are likely not in their original locations after the planet’s reorientation.

“We’re seeing signs of ancient landscapes that formed in places and in ways we can’t really explain in Pluto’s current orientation,” said New Horizons co-investigator Oliver White of the SETI Institute.

“We suggest the possibility is that they formed when Pluto was oriented differently in its early history and were then moved to their current location by true polar wander,” he continued.

Another discovery ties to the Kuiper Belt object Arrokoth. This snowman-like object is classified as a “contact binary” object, meaning it was once two objects that had orbited each other. Now, the two objects have fused together.

Researchers observed large mounds on the surface of the largest object to discover how the objects came together in the past. Scientists theorize that these mounds are evidence of the merging process.

The largest Arrokoth object is composed of 12 distinct mounds that were assembled around a larger central mound.

New Horizons principal investigator Alan Stern of Southwest Research Institute in Boulder, Colorado, said that he found the discovery of Arrokoth “surprising.”

“We discovered that the mounds are similar in many respects, including their sizes, reflectivities and colors,” said Stern, according to NASA.

“We believe the mounds were likely individual components that existed before the assembly of Arrokoth, indicating that like-sized bodies were formed as precursors to Arrokoth itself,” he continued.

The New Horizons craft’s final discovery was that parts of Pluto’s surface are composed entirely of methane ice. These locations on the planet’s surface were viewed during the New Horizons craft’s closest approach to the planet.

Researchers believe that the “bladed terrain” indicates how the planet responds to changes in climate and that this terrain covers a large part of the equator.

“The presence of these bladed terrains on Pluto provides important new insights into the geology and dynamics of Pluto’s surface,” said Ishan Mishra, a science contributor from NASA’s Jet Propulsion Laboratory, according to NASA.

“That they appear under certain conditions in distinct locations also tells us how the surface responds to environmental changes,” he continued.

The New Horizons probe has now been in space for 17 years and is over 5 billion miles away from the planet.

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