[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-291315-105":3,"detail-sidebar-cat-0-en-105":81,"doc-detail-291315-en":130},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","extended-versions-of-mpc-data-files-based-on-the-mpcorb-format-a-guide","Extended Versions of MPC Data Files Based on the MPCORB Format - A Guide","","Guide to extended MPC data files built on the MPCORB fixed-width orbit format. Explains why MPCORB.DAT was originally designed as a flat text file, then describes the move toward easier-to-parse “extended” outputs such as _extended.dat and _extended.json, typically distributed as gzipped files. Details how extended DAT files preserve the original column structure while adding extra columns, and provides reference tables for format definitions, column meanings, and orbit-type flag encoding, plus update context.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/technology/","Technology",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/extended-versions-of-mpc-data-files-based-on-the-mpcorb-format-a-guide/291315/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/extended-versions-of-mpc-data-files-based-on-the-mpcorb-format-a-guide/291315.png","ImageObject",300,407,{"name":42,"@type":43},"Emma Wilson","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-08","2026-09-17",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",7,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"What are the “extended” versions of MPCORB-based data files?","Question",{"text":63,"@type":64},"For files that follow the MPCORB data format, new versions are created as [FILENAME]_extended.dat and [FILENAME]_extended.json, with the extended files available gzipped.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"How do extended DAT files relate to the original MPCORB.DAT format?",{"text":68,"@type":64},"Extended DAT files keep the original fixed-width column structure of MPCORB.DAT and add extra columns at the end.",{"name":70,"@type":61,"acceptedAnswer":71},"Why did MPC add extended formats beyond the original MPCORB.DAT?",{"text":72,"@type":64},"Growing demand from developers for formats easier to parse (e.g., JSON/CSV/SQL) and the need for additional information beyond what MPCORB.DAT originally provided motivated the extended outputs.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},291315,1790044686,{"code":4,"msg":82,"data":83},"success",[84,88,92,96,101,105,109,114,119,122,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":97,"doc_module":4,"doc_module_name":25,"category_name":98,"show_sort_weight":99,"slug":100},5,"Comic",60,"comic",{"id":102,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":103,"slug":104},6,50,"technology",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":106,"show_sort_weight":107,"slug":108},"Healthcare",40,"healthcare",{"id":110,"doc_module":4,"doc_module_name":25,"category_name":111,"show_sort_weight":112,"slug":113},8,"Research & Report",30,"research-report",{"id":115,"doc_module":4,"doc_module_name":25,"category_name":116,"show_sort_weight":117,"slug":118},9,"Religion & Spirituality",20,"religion-spirituality",{"id":117,"doc_module":4,"doc_module_name":25,"category_name":120,"show_sort_weight":117,"slug":121},"World Cup","world-cup",{"id":123,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":123,"slug":125},10,"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":97,"slug":129},19,"General","general",{"code":4,"msg":82,"data":131},{"doc_id":79,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":102,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":110,"language":139,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":12,"update_tm":143,"read_time":117},3848291630094,"https://eur-avatar.wpscdn.com/davatar_085a072bc5b1113ac321206ff7593b45","Guide to the Extended Versions of MPC Data Files Based on the MPCORB Format  \nLast updated: 2024/05/08  \nby J.L. Galache  \nIntroduction  \nThe Minor Planet Center (MPC) has been providing the orbits of minor planets in the form of a file, MPCORB.DAT, since the mid '90s (1990s, not 1890s) . Back then there were only a few thousand known asteroids, compared to the several hundred thousand of today, so a flat text file was the appropriate way to circulate these data. It was also a time when most orbit computations were programmed in Fortran, which ingested data no other way.  \nMPCORB.DAT has therefore always been, and continues to be, a fixed-width file (see Table 1 for the current format description 1) . In fact, all original data files available on the MPC website are flat text files (even the orbits files provided for planetarium-type/sky simulation software packages are simply text files of varying format2) .  \nIn the early years of the 2010s, possibly due to the rising popularity of the scripting language Python amongst astronomers, and an increased interest from developers wanting to write asteroid-themed tools, requests were received to provide data in other, easier to parse formats, e.g., JSON, CSV, SQL, etc.  \nAt the same time, astronomers and developers alike wanted more information than was currently been provided in MPCORB.DAT; information that did exist on the MPC website in other, often hard to find, files. Here was an opportunity to add some new data to existing files, while also making them available in other formats.  \nProviding the core of the MPC's datafiles in JSON format is a step towards a more flexible supply of data to the world. As time permits, it is hoped other formats will follow.  \nThis document provides information on these new files.  \nAny comments can be sent through the MPC Contact page.  \nThe “extended” Family of Files  \nFor files that adhere to the MPCORB data format, new versions have been created called [FILENAME]_extended.dat and [FILENAME]_extended.json. Table 2 lists the files available in“extended” versions. Note that these files are only available Gzipped.  \nContents of the extended DAT files  \nThese files retain the fixed-width column structure of the original MPCORB format (see Table 1) but have some extra columns added at the end. See Table 3 for the listing.  \n1 Also found at its primary location: [http://www.minorplanetcenter.org/iau/info/MPOrbitFormat.html](http://www.minorplanetcenter.org/iau/info/MPOrbitFormat.html).  \n2 They can be found at: [http://www.minorplanetcenter.net/iau/Ephemerides/SoftwareEls.html](http://www.minorplanetcenter.net/iau/Ephemerides/SoftwareEls.html).  \nTable 1: MPCORB format description.  \n\n| Columns | Format3 | Use |\n| --- | --- | --- |\n| 1–7 | a7 | Number or provisional designation (in packed form) |\n| 9–13 | f5.2 | Absolute magnitude, H |\n| 15–19 | f5.2 | Slope parameter, G |\n| 21–25 | a5 | Epoch (in packed form, .0 TT) |\n| 27–35 | f9.5 | Mean anomaly at the epoch (degrees) |\n| 38–46 | f9.5 | Argument of perihelion, J2000.0 (degrees) |\n| 49–57 | f9.5 | Longitude of the ascending node, J2000.0 (degrees) |\n| 60–68 | f9.5 | Inclination to the ecliptic, J2000.0 (degrees) |\n| 71–79 | f9.7 | Orbital eccentricity, e |\n| 81–91 | f11.8 | Mean daily motion (degrees per day) |\n| 93–103 | f11.7 | Semimajor axis, a (AU) |\n| 106 | i1 | Uncertainty parameter, U |\n|  | a1 | If this column contains 'E' it indicates that the orbital eccentricity was assumed. For one-opposition orbits this column can also contain 'D' if a double (or multiple) designation is involved or 'F' if an e-assumed\u003Cbr>double (or multiple) designation is involved. |\n| 108–116 | a9 | Reference |\n| 118–122 | i5 | Number of observations |\n| 124–126 | i3 | Number of oppositions |\n| For multiple-opposition orbits: |  |  |\n| 128–131 | i4 | Year of first observation |\n| 132 | a1 | ' '\u003Cbr>- |\n| 133–136 | i4 | Year of last observation |\n| For single-opposition orbits: |  |  |\n| 128–131 | i4 | Arc length (day","cbCaib35gHNZdiIG","https://ap.wps.com/l/cbCaib35gHNZdiIG","pdf",312926,"English","# Introduction\n## The “extended” Family of Files\n## Contents of the extended DAT files\n## MPCORB format description (Table 1)\n## Extended files list (Table 2)","[{\"question\":\"What are the “extended” versions of MPCORB-based data files?\",\"answer\":\"For files that follow the MPCORB data format, new versions are created as [FILENAME]_extended.dat and [FILENAME]_extended.json, with the extended files available gzipped.\"},{\"question\":\"How do extended DAT files relate to the original MPCORB.DAT format?\",\"answer\":\"Extended DAT files keep the original fixed-width column structure of MPCORB.DAT and add extra columns at the end.\"},{\"question\":\"Why did MPC add extended formats beyond the original MPCORB.DAT?\",\"answer\":\"Growing demand from developers for formats easier to parse (e.g., JSON/CSV/SQL) and the need for additional information beyond what MPCORB.DAT originally provided motivated the extended outputs.\"}]","Extended Versions of MPC Data Files Based on the MPCORB Format - A Guide | PDF",1789644511]