190,369 research outputs found
DLR Advanced Study Group: KUBE² - Analysis about the possibilities of Kuiper Belt Exploitation and Exploration
No full textImpact craters on Pluto and Charon indicate a deficit of small Kuiper belt objects
No full textSinger, K.N., et al., "Impact craters on Pluto and Charon indicate a deficit of small Kuiper belt objects." Science 363, 6430 (March 2019): p. 955-9 doi 10.1126/SCIENCE.AAP8628 ©2019 Author(s)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. ©201
ALSOS Mission Part 1
No full textVarious reports and documents pertaining to the ALSOS Mission, which was part of the Manhattan Project
Understanding the Origin of Planetary Systems: Studying the Kuiper Belt and the Dynamics of Planet Formation
No full textThis thesis presents theoretical and observational studies pertaining to the early solar system, planet formation and extrasolar planets.
First, we explore the dynamics of protoplanet formation. We find that the growth of protoplanets may be dominated by the accretion of a planetesimal disk that forms from planetesimal-planetesimal collisions, rather than direct planetesimal impacts onto the protoplanet. This has far reaching implications for the formation of planets, their growth rate and dynamics. We focus on the implications for planetary spins: it can explain the prevalence of prograde spins of planets and asteroids in the solar system, which is commonly believed to be an accident.
Second, we present a series of investigations of the formation of multiple systems in the Kuiper Belt. Two of our studies are concerned with the formation of comparable mass binaries. We find that in a dynamically cold Kuiper Belt, binaries become bound predominantly by dynamical friction. This leads to a binary population with mostly retrograde mutual binary orbits. In a dynamically hot Kuiper Belt three-body gravitational interactions dominate the binary formation producing a roughly equal number of prograde and retrograde binaries. We propose a new formation scenario for Haumea’s collisional family. In our scenario, the family members are ejected while in orbit around Haumea rather than directly from Haumea’s surface as previously proposed. Our formation scenario offers an explanation for the observed velocity dispersion among the family members which is much smaller than Haumea’s escape velocity. It is consistent with detecting just one collisional family in the Kuiper Belt and aids with explaining Haumea’s initial giant impact.
We conclude with observational work that aims to detect sub-km sized Kuiper Belt objects and to measure their size-distribution. Our results provide the best constraint on the surface density of small Kuiper Belt objects to date. Our findings support the idea that small Kuiper Belt objects underwent collisional evolution that modified their size distribution. We present our first candidate occultation event and show that it is unlikely to be due to instrumental artifacts or statistical fluctuations in the data.</p
Improving the clinical and molecular recognition of pediatric cancer predisposition
No full textContains fulltext :
118624.pdf (Publisher’s version ) (Open Access)Radboud Universiteit Nijmegen, 26 november 2013Promotores : Hoogerbrugge, N., Hoogerbrugge, P. Co-promotores : Ligtenberg, M.J.L., Kuiper, R.P
Geology of the Kuiper quadrangle (H06), Mercury
No full textThe Kuiper quadrangle (H06) is located at the equatorial zone of Mercury and encompasses the area between 288°E–360°E and 22.5°N–22.5°S. Using the NASA MESSENGER data, we compiled a geological map of the quadrangle at a 1:3,000,000 scale. The mapping was mainly based on photo-interpretation of an MDIS (Mercury Dual Imaging System) monochrome 166 m/pixel basemap. Additional datasets were also considered: stereo-DTM of the region, mosaics with high-incidence illumination, and the MDIS global color mosaic. The map shows that the quadrangle is characterized by the prevalence of crater materials which are distinguished into three classes based on their degradation degree. Different plain units were also identified and classified on the basis of their density of cratering. Several structures, mainly represented by contractional faults, were mapped in all quadrangle areas. The map represents the first complete geologic survey of H06 at this scale and provides a highly detailed analysis of the Kuiper quadrangle’s surface geology
The state of knowledge concerning the Kuiper belt
No full textThe arguments for and against the idea that most short-period comets originate in the Kuiper belt are discussed. Observational constraints on the distribution of mass in the Kuiper belt are reviewed as well as a model of the physical conditions that now exist. Finally, predictions from this model about the detectability of the Kuiper belt are compared to optical surveys
ALSOS Mission Part 2
No full textVarious reports, letters, notes, and documents pertaining to the ALSOS Mission, which was part of the Manhattan Project
A Small triptych of our liberation : the images of barth rosezweig lenin
No full textDosterbeek146 p.; 21 c
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