[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-144975-105":3,"detail-sidebar-cat-0-en-105":64,"doc-detail-144975-en":113},{"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":57,"head_meta":59,"extra_data":61,"updated_unix":63},105,"en","the-moons-surface","The Surface of the Moon | PDF","","This issue explains how the Moon’s surface is shaped and why it looks so different from Earth. It describes crater formation from high-speed impacts, contrasting the Moon’s lack of atmosphere and water with Earth’s erosion, volcanoes, earthquakes, and crustal drift that erase scars over geologic time. It further outlines crater characteristics such as circularity, rays and ejecta, central peaks, and the formation of large impact basins, then introduces maria (lowlands) and highlands.",{"@graph":14,"@context":56},[15,34],{"@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/research-report/","Research & Report",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/the-moons-surface/144975/",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/the-moons-surface/144975.png","ImageObject",300,407,{"name":42,"@type":43},"Mason","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-04","2026-08-26",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",10,"https://schema.org",{"og:url":32,"og:type":58,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":60,"canonical":32},"index,follow",{"doc_id":62,"site_id":7},144975,1787713988,{"code":4,"msg":65,"data":66},"success",[67,71,75,79,84,89,94,98,103,106,109],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":68,"show_sort_weight":69,"slug":70},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":72,"show_sort_weight":73,"slug":74},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":76,"show_sort_weight":77,"slug":78},"Exam",70,"exam",{"id":80,"doc_module":4,"doc_module_name":25,"category_name":81,"show_sort_weight":82,"slug":83},5,"Comic",60,"comic",{"id":85,"doc_module":4,"doc_module_name":25,"category_name":86,"show_sort_weight":87,"slug":88},6,"Technology",50,"technology",{"id":90,"doc_module":4,"doc_module_name":25,"category_name":91,"show_sort_weight":92,"slug":93},7,"Healthcare",40,"healthcare",{"id":95,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":96,"slug":97},8,30,"research-report",{"id":99,"doc_module":4,"doc_module_name":25,"category_name":100,"show_sort_weight":101,"slug":102},9,"Religion & Spirituality",20,"religion-spirituality",{"id":101,"doc_module":4,"doc_module_name":25,"category_name":104,"show_sort_weight":101,"slug":105},"World Cup","world-cup",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":107,"show_sort_weight":55,"slug":108},"Lifestyle","lifestyle",{"id":110,"doc_module":4,"doc_module_name":25,"category_name":111,"show_sort_weight":80,"slug":112},19,"General","general",{"code":4,"msg":65,"data":114},{"doc_id":62,"user_id":115,"nickname":42,"user_avatar":116,"doc_module":4,"category_id":95,"category_name":29,"doc_title":117,"doc_description":12,"doc_content":118,"file_id":119,"file_url":120,"file_type":121,"file_size":122,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":85,"language":123,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":124,"faqs":11,"seo_title":10,"seo_description":12,"update_tm":63,"read_time":125},5909887256941,"https://ap-avatar.wpscdn.com/davatar_9964176cb1d06d4a9deccf72a44ae3dc","The Surface of the Moon","[www.astrosociety.org/uitc](www.astrosociety.org/uitc)  \nNo. 13-Fall 1989  \n© 1989, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112  \nThe Surface of the Moon  \nEditor's Note  \nThis year has marked the 20th anniversary of one of the most noteworthy events in the history of our species: our first steps on another world. The Universe in the Classroom has celebrated the July 20, 1969, walk on the Moon by Neil Armstrong and Edwin Aldrin by devoting its 1989 pages to our planet's big satellite. In this final issue of the year, we consider the Moon's alien surface features,(so different from those we're used to on Earth) and review the golden age of lunar exploration.  \nEarth and Moon Compared  \nThe Moon's landscape is starkly different from the Earth's. Instead of being dominated by continents and oceans, the Moon's face is everywhere pockmarked by craters — circular pits or basins blasted out by highspeed impacts of interplanetary debris over the history of the solar system. The craters bear silent witness today to a time — billions of years ago — when collisions of such debris with larger bodies were much more common.  \nThe Earth, too, must have experienced a wealth of such impacts, but our dynamic planet has several characteristics that erase craters relatively quickly (on the geologic time scale)—or even prevent them from forming in the first place:  \n Earth's atmosphere burns up the smaller pieces of asteroidal metal and rock or cometary ice by friction. A typical speed of such a meteoroid is about 25,000 kilometers per hour — and intense heat from friction with the air vaporizes them; as they burn up, we see their quick fiery trails as meteors (sometimes called \"shooting stars\") . The Moon has no atmosphere, so even the tiniest bit of high-speed dust can hit the surface and cause a crater to form.  \n On Earth, erosion due to water and wind eventually erases the craters caused by impacts of objects large enough to hit the ground. Depending on the climate conditions at an impact site, a crater about a kilometer across (such as the famous Meteor Crater in Arizona) can be eroded beyond recognition in a hundred thousand years or so. (Note that a hundred thousand years is only 1/10,000 of a billion years  \n— and we believe the age of the solar system to be about four and a half billion years.) The Moon has no air or water to erode a crater away — it still bears scars billions of years old.  \n Surface activity on the Earth — that is, volcanoes, earthquakes, and the slow motions of its crust called continental drift — eventually masks even the largest impact craters over periods of millions to hundreds of millions of years. The Moon is a geologically dead world now, so it lacks this \"healing\"process, too.  \nCrater Formation  \nWe might expect that impact craters would have a variety of shapes, depending on the angle at which the bombarding chunk hit the ground — that only impacts from directly overhead would produce circular craters. However, all but a very few, small lunar craters are circular. (In fact, the circularity of the Moon's craters was long used as an argument against the so-called \"impact hypothesis\" for making the craters.)  \nHowever, the impacts that formed most craters on the Moon (and elsewhere) did so by literally exploding, not just by gouging up the ground. Craters formed by such detonations — similar to those made by artillery shells— are circular regardless of what direction the projectiles came from.  \nThe energy source for an impact's explosion is the raw speed of the impacting object. An interplanetary chunk headed toward the Moon is accellerated by the Moon's gravity; astronomers' calculations indicate that an object falling from deep space will have a minimum speed of about 5,000 mph on impact. At that speed, the sudden collision of a meteoroid (as these cosmic pieces of debris are called) with the Moon's surface generates enough heat to vaporize much or all of itself and some o","cbCairF8l6kGTvXd","https://ap.wps.com/l/cbCairF8l6kGTvXd","pdf",98370,"English","# The Surface of the Moon - Editor's Note\n# Earth and Moon Compared\n## Crater preservation on the Moon vs Earth\n# Crater Formation\n## Circular craters and impact energy\n# Craters' Features\n## Central peaks and rays\n# Maria (the Lowlands) and the Highlands",15]