Using the data from New Horizons from Pluto-Charon in 2015, a team of scientists discovered indirectly a striking and surprising lack of very small objects in the Kuiper Belt. Evidence of the lack of small Kuiper Belt (KBO) objects comes from the New Horizons visualizations that have revealed the lack of small craters on the largest Pluto, Charon satellite system, indicating that an impactor with a diameter of between 91 m and 1.6 km must also be rare.
The Kuiper Belt is a licking area of ice bodies outside of Neptune's orbit. Since the small Kuiper belts were part of the "raw material" from which the planets originated, this research provides new insights into how the solar system originated. This research was published in the journal March 1 Science.
"These smaller Kuiper Belt objects are too small to actually be seen on any telescope at such distances," said Dr. Kelsi Singer of SwRI, the lead author of the article and co-investigator of NASA New Horizons. "The new horizons that were flying directly over the Kuiper Belt and collecting data were the key to learning about the large and small bodies of the belt."
"This breakthrough breakthrough New Horizons has profound implications," added the mission chief investigator Dr. Alan Stern, also from SwRI. "As New Horizons revealed Pluto, its moons and recently KBO dubbed Ultima Thule in amazing detail, Dr. Singer's team revealed key details about the KBO population on scales that can not be brought closer to direct vision from Earth."
The craters on the solar system objects record the impacts of smaller bodies, provide information about the history of the object and its location in the solar system. Because Pluto is so far from the Earth, little has been known about the surface of the dwarf planet until the epic 2015. Observation of the Pluto and Charon areas revealed a number of characteristics, including mountains that reach up to 13,000 feet (4 km) and large nitrogen glaciers. The geological processes at Pluto erased or changed some evidence of the history of their impacts, but Charon's relative geological strike provided a more stable impact record.
"The main mission of New Horizons is to better understand the Kuiper belt," Singer said, whose research environment, which explored the geology of the ice ages of Saturn and Jupiter, elevates it to understand the superficial processes seen on KBO. "With the success of Ultima Thulla at the beginning of this year, we now have three studied surfaces of the planets, using Pluto-Charon platoon data indicating fewer craters than expected, and Ultima Thule's preliminary results support this finding."
Typical planetary models show that 4.6 billion years ago, the solar system consisted of the gravitational collapse of a giant molecular cloud. The sun, planets, and other objects that form in the surrounding cloud as material collide together in a process known as accretion. Different models result in different populations and location of objects in the solar system.
"This surprising lack of small KBOs changes our view of Kuiper's belt and shows that either its formation or evolution, or both, were somewhat different from those found between the asteroid belt between Mars and Jupiter," Singer said. "Perhaps the asteroid belt has more small bodies than the Kuiper belt because its population is experiencing a greater number of collisions that divide larger objects into smaller ones."
Southwest Research Institute. .