Planetary and Space Science

Planetary and Space Science

8 Pages · 2013 · 3.23 MB · English

Small crater populations on Vesta S. Marchia,f,n, W.F. Bottkea, D.P. O'Brienb, P. Schenkc, S. Mottolad, M.C. De Sanctise, D.A. Kringf, D.A. Williamsg, C.A. Raymondh

Planetary and Space Science free download

Small crater populations on Vesta S. Marchi a,f, n, W.F. Bottke a, D.P. O'Brien b, P. Schenk c, S. Mottola d, M.C. De Sanctis e, D.A. Kring f, D.A. Williams g, C.A. Raymond h, C.T. Russell i aNASA Lunar Science Institute, Southwest Research Institute, Boulder, CO, USAbPlanetary Science Institute, Tucson, AZ, USAcLunar and Planetary Institute, Houston, TX, USAdInstitut für Planetenforschung, DLR-Berlin, GermanyeIstituto Nazionale d'Astrofisica, Roma, ItalyfNASA Lunar Science Institute, USRA—Lunar and Planetary Institute, Houston, TX, USAgArizona State University, Tempe, AZ, USAhJet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USAiUniversity of California, Los Angeles, CA, USA article info Article history: Received 18 December 2012 Received in revised form 30 April 2013 Accepted 3 May 2013 Keywords: Asteroid (4) Vesta Asteroid cratering Asteroid evolution Main belt asteroids abstract The NASA Dawn mission has extensively examined the surface of asteroid Vesta, the second most massive body in the main belt. The high quality of the gathered data provides us with a unique opportunity to determine the surface and internal properties of one of the most important and intriguing main belt asteroids (MBAs). In this paper, we focus on the size frequency distributions (SFDs) of sub-kilometer impact craters observed at high spatial resolution on several selected young terrains on Vesta. These small crater populations offer an excellent opportunity to determine the nature of their asteroidal precursors (namely MBAs) at sizes that are not directly observable from ground-based telescopes (i.e., below∼100 m diameter). Moreover, unlike many other MBA surfaces observed by spacecraft thus far, the young terrains examined had crater spatial densities that were far from empirical saturation. Overall, wefind that the cumulative power- law index (slope) of small crater SFDs on Vesta is fairly consistent with predictions derived from current collisional and dynamical models down to a projectile size of∼10 m diameter (e.g.,Bottke et al., 2005a,b). TheshapeoftheimpactorSFDforsmallprojectilesizesdoesnotappeartohavechangedoverthelastseveral billions of years, and an argument can be made that the absolute number of small MBAs has remained roughly constant (within a factor of 2) over the same time period. The apparent steady state nature of the main

------------- Read More -------------

Download planetary-and-space-science.pdf

Planetary and Space Science related documents

DEPARTMENT of HEALTH and HUMAN - Centers for Disease Control and

507 Pages · 2008 · 6.61 MB · English

influenza, natural disasters, and terrorism, while remaining focused on the threats to health and local, tribal and territorial health network.

Immigration and Economy in the Globalization Process

236 Pages · 2002 · 1.63 MB · English

will need employees with the right skills and motivation. Switching to an active im- Finland by analyzing the development of the volume of foreign-born and foreign na- tionals and direct foreign . In the globalization trend of corporations, competition has shifted from natural re- source and expen

Interpreting sloppy stick figures by graph rectification and

14 Pages · 2001 · 822 KB · English

1 Interpreting sloppy stick figures by graph rectification and constraint-based matching. James V. Mahoney and Markus P. J. Fromherz Xerox Palo Alto Research Center

Assistance and Accountability in Externally Managed Schools

37 Pages · 2008 · 263 KB · English

Edison Schools, Inc., is the largest and most visible among a growing number of. Education Management profit EMOs were managing 521 public schools serving nearly 240,000 students across the United . educational services; and management consulting under the “Edison Alliance” flag, through 

An integrated approach to product design and process selection

48 Pages · 2011 · 2.15 MB ·

Narayan Raman .. M? < Bs% .. a geometric series given by TEMP(y) = r * TEMP(

Normal Curve Equivalents and Percentiles

1 Pages · 2009 · 385 KB · English

Title: A.1-(28)_FINAL_Percentiles_NCEs_2009-08-23 Author: Dee McMann Created Date: 10/28/2009 3:50:39 PM

Afghanistan Floods and Landslide

12 Pages · 2014 · 585 KB · English

are Health and care (mobile health teams, psychosocial support and CBHFA), Water and Sanitation (distribution of .. health teams (MHTs, including deployment of teams across regions) working closely with CBHFA volunteers, psycho When operating, they erect a tent that serves as an OPD ward.

Word-Level Language Identification and Predicting Codeswitching Points in Swahili-English ...

9 Pages · 2016 · 136 KB · English

Proceedings of the Second Workshop on Computational Approaches to Code Switching, pages 21–29,. Austin, TX, November 1, 2016. cO2016 conveys meaning (Myers-Scotton, 1993b). A model should be able to see this Solorio and Liu look at English-Spanish codeswitching in a relatively small 


4 Pages · 2012 · 111 KB · English


Mesoamerica and South America

1 Pages · 2004 · 690 KB · English

MESOAMERICA World of the Aztecs Land of the Maya I n c a / I n k a E m p i r e SOUTH AMERIC Mesoamerica and South America Key Machu Picchu Tenochitlan Chichen Itza