Source: Journal of Geophysical Research: Planets
Due to their pristine state Kuiper Belt Objects (KBOs) may offer the best opportunity to study the formation of planetesimals in the early solar system, but due to their large distance from the sun, these objects are incredibly difficult to observe. Furthermore, limited geophysical information can be extracted from telescopic observations. In 2019, NASA’s New Horizons spacecraft took a close look at the KBO called Arrokoth, the least evolved KBO ever studied in situ.
Investigating the geophysical environment of Arrokoth using the latest shape models, Keane et al.  show that bright material accumulates in low standing areas and that material can be mobilized and move downslope. Further, Arrokoth’s bulk density as inferred from the New Horizons observations is exceptionally low and comparable to fresh snow on Earth. This indicates that during the successive accretion of the object compaction must have been limited, implying that its formation process must have been very gentle.
The New Horizons spacecraft will continue to contribute to the study of KBOs and the early solar system by observing further KBOs from within the Kuiper Belt during its extended mission.
Citation: Keane, J. T., Porter, S. B., Beyer, R. A., Umurhan, O. M., McKinnon, W. B., Moore, J. M., et al. (2022). The Geophysical Environment of (486958) Arrokoth— A Small Kuiper Belt Object Explored by New Horizons. Journal of Geophysical Research: Planets, 127, e2021JE007068. https://doi.org/10.1029/2021JE007068
—Matthias Grott, Associate Editor, Journal of Geophysical Research: Planets