Using New Horizons data from the Pluto-Charon flyby in 2015, a Southwest Research Institute-led team of scientists have indirectly discovered a distinct and surprising lack of very small objects in the Kuiper Belt. The evidence for the paucity of small Kuiper Belt objects (KBOs) comes from New Horizons imaging that revealed the small craters on Pluto's largest satellite, Charon, indicating that impactors from 300 feet to 1 mile (91 meters to 1.6 km) in diameter must also be rare.
The Kuiper Belt is a donut-shaped region of icy bodies beyond the orbit of Neptune. Because small Kuiper Belt objects are some of the "feedstock" from which planets formed, this research provides new insights into how the solar system originates. This research was published in the March 1 issue of the prestigious journal Science .
"These smaller Kuiper Belt objects are much too small to really see with any telescopes at such a great distance," said SwRI's Dr. . Kelsi Singer, the paper's lead author and a co-investigator or NASA's New Horizon mission. "New Horizons flying directly through the Kuiper Belt and collecting data there were key to learning about both large and small bodies of the belt."
"This breakthrough discovery at New Horizons has deep implications," added the mission's principal investigator, Dr . Alan Stern, or SwRI. "Just like New Horizons revealed Pluto, its moons, and more recently, the KBO nicknamed Ultima Thule in an exquisite detail, Dr. Singer's team revealed key details about the population of KBOs at scales we cannot come close to directly seeing from Earth." 19659007] SwRI led New Horizons research indicates small Kuiper Belt objects are surprisingly rare “/>
Craters on solar system objects record the impacts of smaller bodies, providing hints about the history of the object and its place in the solar system. Because Pluto is so far from Earth, little was known about the dwarf planet's surface until the epic 2015 flyby. Observations of the surfaces of Pluto and Charon revealed a variety of features, including mountains that reach as high as 13,000 feet (4 km) and fixed glaciers or nitrogen ice. Geologic processes on Pluto have been edited or altered by the evidence of its impact history, but Charon's relative geologic stasis has provided a more stable record of impacts.
"A major part of the mission of New Horizons is to better understand the Kuiper Belt, "said Singer, whose research background studying the geology of the icy moons of Saturn and Jupiter positions here to understand the surface processes seen on CBOs. "With the successful flyby of Ultima Thule early this year, we now have three distinct planetary surfaces to study. This paper uses the data from the Pluto-Charon flyby, which indicates fewer small impacts than expected. And preliminary results from Ultima Thule support this finding. "
Typical planetary models show that 4.6 billion years ago, the solar system formed from the gravitational collapse of a giant molecular cloud. The Sun, the planets and other objects formed as materials within the collapsing cloud clumped together in a process known as accretion. Different models result in different populations and locations of objects in the solar system.