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.

scholarly journals Initial results from the New Horizons exploration of 2014 MU69, a small Kuiper Belt object

Science ◽  
2019 ◽  
Vol 364 (6441) ◽  
pp. eaaw9771 ◽  
Author(s):  
S. A. Stern ◽  
H. A. Weaver ◽  
J. R. Spencer ◽  
C. B. Olkin ◽  
G. R. Gladstone ◽  
...  
Keyword(s):  
Kuiper Belt ◽  
Low Velocity ◽  
Surface Color ◽  
Kuiper Belt Object ◽  
New Horizons ◽  
Contact Binary ◽  
Geological Units ◽  
Distant Region ◽  
Initial Results ◽  
Solar Wind Interactions

The Kuiper Belt is a distant region of the outer Solar System. On 1 January 2019, the New Horizons spacecraft flew close to (486958) 2014 MU69, a cold classical Kuiper Belt object approximately 30 kilometers in diameter. Such objects have never been substantially heated by the Sun and are therefore well preserved since their formation. We describe initial results from these encounter observations. MU69 is a bilobed contact binary with a flattened shape, discrete geological units, and noticeable albedo heterogeneity. However, there is little surface color or compositional heterogeneity. No evidence for satellites, rings or other dust structures, a gas coma, or solar wind interactions was detected. MU69’s origin appears consistent with pebble cloud collapse followed by a low-velocity merger of its two lobes.

scholarly journals The geology and geophysics of Kuiper Belt object (486958) Arrokoth

Science ◽  
2020 ◽  
Vol 367 (6481) ◽  
pp. eaay3999 ◽  
Author(s):  
J. R. Spencer ◽  
S. A. Stern ◽  
J. M. Moore ◽  
H. A. Weaver ◽  
K. N. Singer ◽  
...  
Keyword(s):  
Solar System ◽  
Smooth Surface ◽  
Kuiper Belt ◽  
Solar System Formation ◽  
Small Bodies ◽  
Kuiper Belt Object ◽  
New Horizons ◽  
Geological Features ◽  
Solar System Bodies ◽  
Contact Binary

The Cold Classical Kuiper Belt, a class of small bodies in undisturbed orbits beyond Neptune, is composed of primitive objects preserving information about Solar System formation. In January 2019, the New Horizons spacecraft flew past one of these objects, the 36-kilometer-long contact binary (486958) Arrokoth (provisional designation 2014 MU69). Images from the flyby show that Arrokoth has no detectable rings, and no satellites (larger than 180 meters in diameter) within a radius of 8000 kilometers. Arrokoth has a lightly cratered, smooth surface with complex geological features, unlike those on previously visited Solar System bodies. The density of impact craters indicates the surface dates from the formation of the Solar System. The two lobes of the contact binary have closely aligned poles and equators, constraining their accretion mechanism.

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 Organic Components of Small Bodies in the Outer Solar System: Some Results of the New Horizons Mission

Life ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 126
Author(s):  
Dale P. Cruikshank ◽  
Yvonne J. Pendleton ◽  
William M. Grundy
Keyword(s):  
Solar System ◽  
Kuiper Belt ◽  
Space Environment ◽  
Small Bodies ◽  
Orange Pigment ◽  
Kuiper Belt Object ◽  
New Horizons ◽  
Organic Components ◽  
Key Indicators ◽  
Complex Organic

The close encounters of the Pluto–Charon system and the Kuiper Belt object Arrokoth (formerly 2014 MU69) by NASA’s New Horizons spacecraft in 2015 and 2019, respectively, have given new perspectives on the most distant planetary bodies yet explored. These bodies are key indicators of the composition, chemistry, and dynamics of the outer regions of the Solar System’s nascent environment. Pluto and Charon reveal characteristics of the largest Kuiper Belt objects formed in the dynamically evolving solar nebula inward of ~30 AU, while the much smaller Arrokoth is a largely undisturbed relic of accretion at ~45 AU. The surfaces of Pluto and Charon are covered with volatile and refractory ices and organic components, and have been shaped by geological activity. On Pluto, N2, CO and CH4 are exchanged between the atmosphere and surface as gaseous and condensed phases on diurnal, seasonal and longer timescales, while Charon’s surface is primarily inert H2O ice with an ammoniated component and a polar region colored with a macromolecular organic deposit. Arrokoth is revealed as a fused binary body in a relatively benign space environment where it originated and has remained for the age of the Solar System. Its surface is a mix of CH3OH ice, a red-orange pigment of presumed complex organic material, and possibly other undetected components.

scholarly journals New Horizons Spacecraft to Reach Farthest Body in Solar System Yet

Eos ◽  
2018 ◽  
Vol 99 ◽  
Author(s):  
Jenessa Duncombe
Keyword(s):  
Solar System ◽  
Kuiper Belt ◽  
Kuiper Belt Object ◽  
New Horizons

The flyby of Ultima Thule on New Year’s Day will give us our first glimpse of a mysterious Kuiper Belt object.

The formation and evolution of the solar system

2021 ◽  
Vol 03 (01) ◽  
pp. 85-87
Author(s):  
Türkanə Mirzəli qızı Əliyeva ◽  
◽  
Vəfa Əjdər qızı Qafarova ◽  
Keyword(s):  
Solar System ◽  
Kuiper Belt ◽  
New Horizons ◽  
T Tauri ◽  
Dwarf Planets ◽  
Celestial Bodies ◽  
Extensive Information ◽  
Formation And Evolution ◽  
Red Giant ◽  
Planet X

The article provides extensive information on the formation, evolution and structure of the solar system. It also discusses the planets of the solar system and the dwarf planets. Its noted that the Kuiper objects are the celestial bodies which belongs to the solar system. NASA's New Horizons spacecraft is currently helps studying four objects in the Kuiper belt. There is also talked about TTauri type stars. The article discusses the future transformation of the Sun from a Red Giant to a White Dwarf. Key words: Kuiper Belt, T Tauri Star, Dwarf Planets, Planet X

scholarly journals Photometry of Kuiper belt object (486958) Arrokoth from New Horizons LORRI

Icarus ◽  
2021 ◽  
Vol 356 ◽  
pp. 113723 ◽  
Author(s):  
Jason D. Hofgartner ◽  
Bonnie J. Buratti ◽  
Susan D. Benecchi ◽  
Ross A. Beyer ◽  
Andrew Cheng ◽  
...  
Keyword(s):  
Kuiper Belt ◽  
Kuiper Belt Object ◽  
New Horizons

scholarly journals Surface dynamics, equilibrium points and individual lobes of the Kuiper Belt object (486958) Arrokoth

2020 ◽  
Vol 496 (4) ◽  
pp. 4154-4173 ◽  
Author(s):  
A Amarante ◽  
O C Winter
Keyword(s):  
Equilibrium Points ◽  
Kuiper Belt ◽  
Rotation Period ◽  
Radial Symmetry ◽  
Irregular Shape ◽  
Orbital Energy ◽  
Dynamic Features ◽  
Kuiper Belt Object ◽  
Contact Binary ◽  
Power Curves

ABSTRACT The New Horizons space probe led the first close flyby of one of the most primordial and distant objects left over from the formation of the Solar system, the contact binary Kuiper Belt object (486958) Arrokoth. This is composed of two progenitors, the lobes called Ultima and Thule. In the current work, we investigate Arrokoth’s surface in detail to identify the location of equilibrium points and also we explore each lobe’s individual dynamic features. We assume that Arrokoth’s irregular shape is a homogeneous polyhedra contact binary. We explore its dynamic characteristics numerically by computing its irregular binary geopotential in order to study its quantities, such as geometric height, oblateness, ellipticity and zero-power curves. The stability of Arrokoth Hill was also explored through zero-velocity curves. Arrokoth’s external equilibrium points have no radial symmetry due to its highly irregular shape. We identified even equilibrium points concerning its shape and spin rate: i.e. four unstable external equilibrium points and three inner equilibrium points, where two points are linearly stable, with an unstable central point that has a slight offset from its centroid. Moreover, the large and small lobes each have five equilibrium points with different topological structures from those found in Arrokoth. Our results also indicate that the equatorial region of Arrokoth’s lobes is an unstable area due to the high rotation period, while its polar locations are stable resting sites for surface particles. Finally, the zero-power curves indicate the locations around Arrokoth where massless particles experience enhancing and receding orbital energy.

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
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