New Horizons gives new insight about Pluto, finds bladed terrain

In July 2015, the New Horizons spacecraft had its first close encounter with Pluto and its moons. It went on to explore the icy edge of the solar system, generating a wealth of data in the process. 

The New Horizons team has been sifting through data to solve mysteries about Pluto and our solar system's smaller bodies. The team presented their latest findings at the Lunar and Planetary Science Conference in The Woodlands, Texas, on March 14. At the conference, they announced not one but three key findings.

The formation of Arrokoth

This two-lobed object is so far from the Sun that it has always been frozen solid. Astronomers say it is made up of two objects that once orbited each other before gently merging into one.

The spacecraft made the Arrokoth flyby on New Year’s Day of 2019. Recent research into Arrokoth's primitive structure has revealed new details about the "larger mounds on the larger lobe." They discovered that the lobe comprises 12 clumped, distinct mounds. 

“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. This is surprising, and a new piece in the puzzle of how planetesimals – building blocks of the planets, like Arrokoth and other Kuiper Belt objects come together,” said Alan Stern, New Horizons principal investigator, in a statement.  

The findings could shed important light on the origin and formation of Arrokoth.

The surface shift of Pluto

Another investigation shed light on Pluto's past. Pluto, like Earth, was discovered to have flipped on its side during its early history. Scientists have yet to determine how much the poles shifted. But, the latitudes and longitudes of surface features depict it.

They closely examined Pluto's mass distribution to draw results. And they noticed surface realignment by studying Sputnik Planitia, a heart-shaped feature on Pluto's surface. 

“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 Oliver White, a New Horizons co-investigator from SETI Institute in Mountain View, California. “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,” White added.

Bladed landform on Pluto  

The presence of large swaths of jagged landforms was one strange finding from the flyby. The structures discovered near the hemisphere's edge are thought to be entirely made of methane ice.

The team believes Pluto's changing climate is to blame for the bladed terrain.

“They appear under certain conditions in distinct locations also tells us how the surface responds to environmental changes. The discovery of these features just adds to our understanding of the processes that shape Pluto and other icy planets in our solar system and highlights the complexity, dynamic nature, and diversity of planetary surfaces like Pluto’s, said Ishan Mishra, a postdoctoral researcher and science team contributor from NASA’s Jet Propulsion Laboratory in Pasadena, California.  

According to the findings, these bladed terrains could also be found in other parts of the dwarf planet. Investigating these features could help us learn more about Pluto's geological dynamics.

Meanwhile, New Horizons will continue to return fascinating data for astronomers to decipher. In the coming days, it is also expected to provide insights into the worlds of Uranus and Neptune.

In addition, the team will select the next potential flyby target for New Horizons to study, as well as observe the outer heliosphere.