scholarly journals Impact craters on Pluto and Charon indicate a deficit of small Kuiper belt objects

Science ◽  
2019 ◽  
Vol 363 (6430) ◽  
pp. 955-959 ◽  
Author(s):  
K. N. Singer ◽  
W. B. McKinnon ◽  
B. Gladman ◽  
S. Greenstreet ◽  
E. B. Bierhaus ◽  
...  
Keyword(s):  
High Resolution ◽  
Kuiper Belt ◽  
Impact Craters ◽  
Early Solar System ◽  
Size Frequency Distribution ◽  
Kuiper Belt Objects ◽  
New Horizons ◽  
Relative Paucity ◽  
Extensive Region ◽  
High Resolution Images

The flyby of Pluto and Charon by the New Horizons spacecraft provided high-resolution images of cratered surfaces embedded in the Kuiper belt, an extensive region of bodies orbiting beyond Neptune. Impact craters on Pluto and Charon were formed by collisions with other Kuiper belt objects (KBOs) with diameters from ~40 kilometers to ~300 meters, smaller than most KBOs observed directly by telescopes. We find a relative paucity of small craters ≲13 kilometers in diameter, which cannot be explained solely by geological resurfacing. This implies a deficit of small KBOs (≲1 to 2 kilometers in diameter). Some surfaces on Pluto and Charon are likely ≳4 billion years old, thus their crater records provide information on the size-frequency distribution of KBOs in the early Solar System.

A re-assessment of the Kuiper belt size distribution for sub-kilometer objects

2020 ◽  
Author(s):  
Alessandro Morbidelli ◽  
David Nesvorny ◽  
William Bottke ◽  
Simone Marchi
Keyword(s):  
Solar System ◽  
Size Distribution ◽  
Production Function ◽  
Power Law ◽  
Kuiper Belt ◽  
Spatial Density ◽  
Early Solar System ◽  
Size Frequency Distribution ◽  
New Horizons ◽  
The Impact

<p>In this work we combine several constraints provided by the crater records on Arrokoth and the worlds of the Pluto system to compute the size-frequency distribution (SFD) of the crater production function for craters with diameter D≤ 10km. For this purpose, we use a Kuiper belt objects (KBO) population model calibrated on telescopic surveys, that describes also the evolution of the KBO population during the early Solar System. We further calibrate this model using the crater record on Pluto, Charon and Nix.  Using this model, we compute the impact probability of bodies with diameter d>2km on Arrokoth, integrated over the age of the Solar System, that we compare with the corresponding impact probability on Charon. Our result, together with the observed density of sub-km craters on Arrokoth's imaged surface, constrains the power law slope of the crater production function. Other constraints come from the absence of craters with 1<D<7km on Arrokoth, the existence of a single crater with D>7km and the relationship between the spatial density of sub-km craters on Arrokoth and of D ~ 20km craters on Charon. Together, these data suggest the crater production function on these worlds has a cumulative power law slope of -1.5<q<-1.2. Converted into a projectile SFD slope, we find -1.2<q<sub>KBO</sub><-1.0. These values are close to the cumulative slope of main belt asteroids in the 0.2-2km range, a population in collisional equilibrium (Bottke et al. 2020). For KBOs, however, this slope appears to extend down to objects a few tens of meters in diameter, as inferred from sub-km craters on Arrokoth. From the measurement of the dust density in the Kuiper belt made by the New Horizons mission, we predict that the SFD of the KBOs become steep again below approximately 30m. All these considerations strongly indicate that the size distribution of the KBO population is in collisional equilibrium.</p>

scholarly journals TOPOGRAPHIC MAPPING OF PLUTO AND CHARON USING NEW HORIZONS DATA

2016 ◽  
Vol XLI-B4 ◽  
pp. 487-489 ◽  
Author(s):  
P. M. Schenk ◽  
R. A. Beyer ◽  
J. M. Moore ◽  
J. R. Spencer ◽  
W. B. McKinnon ◽  
...  
Keyword(s):  
High Resolution ◽  
Viscous Flow ◽  
High Impact ◽  
Impact Craters ◽  
Topographic Maps ◽  
Topographic Mapping ◽  
New Horizons ◽  
Rolling Plains

New Horizons 2015 flyby of the Pluto system has resulted in high-resolution topographic maps of Pluto and Charon, the most distant objects so mapped. DEM’s over ~30% of each object were produced at 100-300 m vertical and 300-800 m spatial resolutions, in hemispheric maps and high-resolution linear mosaics. Both objects reveal more relief than was observed at Triton. The dominant 800-km wide informally named Sputnik Planum bright ice deposit on Pluto lies in a broad depression 3 km deep, flanked by dispersed mountains 3-5 km high. Impact craters reveal a wide variety of preservation states from pristine to eroded, and long fractures are several km deep with throw of 0-2 km. Topography of this magnitude suggests the icy shell of Pluto is relatively cold and rigid. Charon has global relief of at least 10 km, including ridges of 2-3 km and troughs of 3-5 km of relief. Impact craters are up to 6 km deep. Vulcan Planum consists of rolling plains and forms a topographic moat along its edge, suggesting viscous flow.

scholarly journals The solar nebula origin of (486958) Arrokoth, a primordial contact binary in the Kuiper Belt

Science ◽  
2020 ◽  
Vol 367 (6481) ◽  
pp. eaay6620 ◽  
Author(s):  
W. B. McKinnon ◽  
D. C. Richardson ◽  
J. C. Marohnic ◽  
J. T. Keane ◽  
W. M. Grundy ◽  
...  
Keyword(s):  
Solar System ◽  
Kuiper Belt ◽  
Solid Particles ◽  
Early Solar System ◽  
Low Velocity ◽  
Kuiper Belt Object ◽  
New Horizons ◽  
Contact Binary ◽  
Collapsing Cloud ◽  
Gas Drag

The New Horizons spacecraft’s encounter with the cold classical Kuiper Belt object (486958) Arrokoth (provisional designation 2014 MU69) revealed a contact-binary planetesimal. We investigated how Arrokoth formed and found that it is the product of a gentle, low-speed merger in the early Solar System. Its two lenticular lobes suggest low-velocity accumulation of numerous smaller planetesimals within a gravitationally collapsing cloud of solid particles. The geometric alignment of the lobes indicates that they were a co-orbiting binary that experienced angular momentum loss and subsequent merger, possibly because of dynamical friction and collisions within the cloud or later gas drag. Arrokoth’s contact-binary shape was preserved by the benign dynamical and collisional environment of the cold classical Kuiper Belt and therefore informs the accretion processes that operated in the early Solar System.

Origins of pits and troughs and degradation on a small primitive planetesimal in the Kuiper Belt: high-resolution topography of (486958) Arrokoth (aka 2014 MU69) from New Horizons

Icarus ◽  
2021 ◽  
Vol 356 ◽  
pp. 113834 ◽  
Author(s):  
Paul Schenk ◽  
Kelsi Singer ◽  
Ross Beyer ◽  
Chloe Beddingfield ◽  
Stuart J. Robbins ◽  
...  
Keyword(s):  
High Resolution ◽  
Kuiper Belt ◽  
New Horizons

scholarly journals Serpentinization in the thermal evolution of icy Kuiper belt objects in the early Solar system

2021 ◽  
Author(s):  
Anikó Farkas-Takacs ◽  
Csaba Kiss ◽  
Sándor Góbi ◽  
Ákos Keresztúri
Keyword(s):  
Solar System ◽  
Thermal Evolution ◽  
Kuiper Belt ◽  
Early Solar System ◽  
Kuiper Belt Objects

scholarly journals Cratering and age of the small Saturnian satellites

2019 ◽  
Vol 627 ◽  
pp. A12
Author(s):  
N. L. Rossignoli ◽  
R. P. Di Sisto ◽  
M. Zanardi ◽  
A. Dugaro
Keyword(s):  
Dynamical System ◽  
Theoretical Model ◽  
High Resolution ◽  
Solar System ◽  
Size Distribution ◽  
Frequency Distribution ◽  
Size Frequency Distribution ◽  
Crater Size ◽  
Small Crater ◽  
High Resolution Images

Context. The small (≤135 km mean radius) satellites of Saturn are closely related to its rings and together they constitute a complex dynamical system where formation and destruction mechanisms compete against each other. The Cassini-Huygens mission provided high-resolution images of the surfaces of these satellites and therefore allowed for the calculation of observational crater counts. Aims. We model the cratering process by Centaur objects on the small Saturnian satellites, and compare our results with the observational crater counts obtained from the Voyager and Cassini missions. Methods. Using a theoretical model previously developed we calculate the crater production on these satellites considering two slopes of the size-frequency distribution (SFD) for the smaller objects of the Centaur population and compare our results with the available observations. In addition, we consider the case of catastrophic collisions between these satellites and Centaur objects and calculate the age of formation of those satellites that suffer one or more disruptions. Results. In general we find that the observed crater distributions are best modeled by the crater size distribution corresponding to the s2 = 3.5 index of the SFD of impactors with diameters smaller than 60 km. However, for crater diameters D ≲ 3–8 km (which correspond to impactor diameters d ~ 0.04–0.15 km), the observed distributions become flatter and deviate from our results, which may evidence processes of erosion and/or crater saturation at small crater sizes or a possible break in the SFD of impactors at d ~ 0.04–0.15 km to a much shallower differential slope of approximately − 1.5. Our results suggest that Pan, Daphnis, Atlas, Aegaeon, Methone, Anthe, Pallene, Calypso, and Polydeuces suffered one or more catastrophic collisions over the age of the solar system, the younger being associated to arcs with ages of ~108 yr. We have also calculated surface ages for the satellites, which indicate ongoing resurfacing processes.

Phase Curves from the Kuiper Belt: Photometric Properties of Distant Kuiper Belt Objects Observed by New Horizons

2019 ◽  
Vol 158 (3) ◽  
pp. 123 ◽  
Author(s):  
Anne J. Verbiscer ◽  
Simon Porter ◽  
Susan D. Benecchi ◽  
J. J. Kavelaars ◽  
Harold A. Weaver ◽  
...  
Keyword(s):  
Kuiper Belt ◽  
Kuiper Belt Objects ◽  
New Horizons

scholarly journals TOPOGRAPHIC MAPPING OF PLUTO AND CHARON USING NEW HORIZONS DATA

2016 ◽  
Vol XLI-B4 ◽  
pp. 487-489
Author(s):  
P. M. Schenk ◽  
R. A. Beyer ◽  
J. M. Moore ◽  
J. R. Spencer ◽  
W. B. McKinnon ◽  
...  
Keyword(s):  
High Resolution ◽  
Viscous Flow ◽  
High Impact ◽  
Impact Craters ◽  
Topographic Maps ◽  
Topographic Mapping ◽  
New Horizons ◽  
Rolling Plains

New Horizons 2015 flyby of the Pluto system has resulted in high-resolution topographic maps of Pluto and Charon, the most distant objects so mapped. DEM’s over ~30% of each object were produced at 100-300 m vertical and 300-800 m spatial resolutions, in hemispheric maps and high-resolution linear mosaics. Both objects reveal more relief than was observed at Triton. The dominant 800-km wide informally named Sputnik Planum bright ice deposit on Pluto lies in a broad depression 3 km deep, flanked by dispersed mountains 3-5 km high. Impact craters reveal a wide variety of preservation states from pristine to eroded, and long fractures are several km deep with throw of 0-2 km. Topography of this magnitude suggests the icy shell of Pluto is relatively cold and rigid. Charon has global relief of at least 10 km, including ridges of 2-3 km and troughs of 3-5 km of relief. Impact craters are up to 6 km deep. Vulcan Planum consists of rolling plains and forms a topographic moat along its edge, suggesting viscous flow.

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