--- title: "Lunar Highlands | Earth Science" description: "Lunar highlands are the Moon's bright, cratered ancient terrain made of anorthosite, showing early lunar history in Earth Science." canonical: "https://fiveable.me/hs-earth-science/key-terms/lunar-highlands" type: "key-term" subject: "Earth Science" unit: "Unit 1" --- # Lunar Highlands | Earth Science ## Definition Lunar highlands are the Moon's older, lighter-colored, heavily cratered regions. In Earth Science, they show the Moon's early crust and the impact history that shaped its surface. ## What It Is Lunar highlands are the Moon's bright, rugged, ancient surface regions, made mostly of anorthosite. They sit higher than the darker maria and cover most of the Moon, so when you look at a moon map, the pale, heavily cratered areas are usually the highlands. In Earth Science, the term is used to describe the Moon's oldest crustal terrain. These rocks formed early in lunar history when a molten outer layer cooled and lighter minerals floated upward to form the crust. That is why the highlands are rich in calcium and aluminum and why they have a lighter color than the basaltic maria. The surface texture matters just as much as the color. The highlands are covered with impact craters of many sizes because they have been around for billions of years and have not been resurfaced much by lava flows. Since the Moon has no real atmosphere, wind, rain, and running water do not erase those craters the way they would on Earth. That makes the highlands a kind of geologic record book. The more cratered an area is, the older it usually is, and the highlands preserve some of the Moon's earliest history. When scientists compare the highlands with the smoother maria, they can tell the difference between ancient crust and later volcanic flooding. You can think of the lunar highlands as the Moon's battered original crust. They are not just "mountains," even though they often look elevated and rough. They are the Moon's oldest surviving surface, and their light color, heavy cratering, and anorthosite composition all point to that origin. ## Why It Matters Lunar highlands matter because they show you what the Moon was like before later lava flows changed parts of its surface. In Earth Science, that makes them one of the best places to study early solar system history without needing a time machine. They also help you compare different kinds of lunar surface processes. The highlands are shaped mostly by impact cratering, while the maria reflect volcanic resurfacing. If you can tell those two regions apart, you can explain why some parts of the Moon are ancient and rough while others are younger and smoother. The term also shows up in questions about composition. Anorthosite, the rock that makes up much of the highlands, tells scientists that the Moon's crust formed differently from the basaltic lava plains in the maria. That difference is a clue to the Moon's cooling and differentiation early on. When you see a lunar image, the highlands help you read the surface instead of just naming it. You can identify old terrain, infer a lack of recent resurfacing, and connect brightness to rock type rather than to temperature or atmosphere. ## Connections ### Anorthosite Anorthosite is the rock most closely linked to the lunar highlands. Its light color comes from the minerals in it, which is why the highlands look brighter than the darker basaltic maria. If a question asks why the highlands are pale, composition is the answer, not lighting or weather. ### [Impact Cratering](/hs-earth-science/key-terms/impact-cratering) The highlands are packed with impact craters because they are very old and have stayed exposed for billions of years. This makes them the best place to study impact cratering on the Moon. Fewer craters usually means younger surface, while the highlands show the opposite. ### Maria Maria are the darker, smoother basalt plains that contrast with the lunar highlands. When you compare the two, you are comparing younger volcanic resurfacing with older crustal terrain. Many Earth Science questions use that contrast to ask you which surface is older or more heavily cratered. ### [Spectroscopy](/hs-earth-science/key-terms/spectroscopy) Spectroscopy is one way scientists identify what the highlands are made of from a distance. By analyzing reflected light, they can infer mineral makeup and distinguish anorthosite-rich highlands from basaltic maria. It is a useful tool when you cannot touch the sample directly. ## On the AP Exam A quiz item or image-ID question may show a lunar surface map and ask you to identify the bright, cratered regions as the highlands. You might also have to explain why they are older than the maria, using crater density and resurfacing as evidence. In a short response, the best move is to connect appearance, composition, and age: lighter color plus rough texture plus many craters equals ancient highland crust. If the prompt compares two lunar regions, use the highlands as the older, more heavily cratered side of the comparison. ## lunar highlands vs Maria Lunar highlands and maria are easy to mix up because both are major Moon surface regions. The highlands are light-colored, rough, and heavily cratered, while the maria are darker, smoother basalt plains formed later by lava flows. If a question asks which region is older, it is usually the highlands. ## Key Takeaways - Lunar highlands are the Moon's bright, ancient, heavily cratered regions. - They are made mostly of anorthosite, which gives them their lighter color. - Because they are so old, they preserve a long record of impact cratering. - The highlands contrast with the darker maria, which are younger basalt plains. - In Earth Science, the highlands help you infer the Moon's early crust and surface history. ## FAQs ### What is lunar highlands in Earth Science? Lunar highlands are the Moon's older, lighter-colored, rugged surface regions. They are made mostly of anorthosite and are covered with many impact craters, which tells you they formed early and have not been resurfaced much. ### Why are the lunar highlands lighter than the maria? The highlands are lighter because they are made mostly of anorthosite, a rock that reflects more sunlight than the basalt in the maria. The difference in color is about composition, not brightness from the Sun or temperature. ### Are lunar highlands the same as lunar maria? No. The highlands are the Moon's older, brighter, more heavily cratered crust, while the maria are darker, smoother lava plains. The two regions show different stages in the Moon's geologic history. ### How do scientists know the lunar highlands are older? They use crater density and surface texture. The highlands have far more impact craters and less resurfacing than the maria, so they are interpreted as much older terrain. ## Related Study Guides - [1.4 The Moon and Its Phases](/hs-earth-science/unit-1/moon-phases/study-guide/YhZHHUPXx59C9Uw2) ## About This Document Canonical Fiveable pages are available as Markdown at the same path plus `.md`. - [llms.txt](https://fiveable.me/llms.txt): index of Fiveable's sections and URL patterns - [llms-full.txt](https://fiveable.me/llms-full.txt): complete subject and unit listing - [MCP server](https://fiveable.me/mcp): call Fiveable as tools instead of fetching pages (`https://fiveable.me/api/mcp`) - [MCP server for AP teachers](https://fiveable.me/mcp/teachers): a teacher's classes, assignments and AP-rubric grading (`https://fiveable.me/api/mcp/teacher`) ## Structured Data ```json {"@context":"https://schema.org","@graph":[{"@type":"LearningResource","@id":"https://fiveable.me/hs-earth-science/key-terms/lunar-highlands#resource","name":"Lunar Highlands | Earth Science","url":"https://fiveable.me/hs-earth-science/key-terms/lunar-highlands","learningResourceType":"Concept explainer","educationalLevel":"AP® / High School","about":{"@id":"https://fiveable.me/hs-earth-science/key-terms/lunar-highlands#term"},"audience":{"@type":"EducationalAudience","educationalRole":"student"},"dateModified":"2026-07-03T02:21:52.120Z","isPartOf":{"@type":"Collection","name":"Earth Science Key Terms","url":"https://fiveable.me/hs-earth-science/key-terms"},"author":{"@type":"Organization","@id":"https://fiveable.me/editorial#content-team","name":"Fiveable Content Team","url":"https://fiveable.me/editorial","parentOrganization":{"@id":"https://fiveable.me/#organization"},"member":[{"@type":"Person","name":"Amanda DoAmaral","sameAs":["https://www.linkedin.com/in/adoamaral"]},{"@type":"Person","name":"Becky Bahr","sameAs":["https://www.linkedin.com/in/becky-bahr-b52743132"]}]},"publisher":{"@type":"Organization","name":"Fiveable","url":"https://fiveable.me"}},{"@type":"DefinedTerm","@id":"https://fiveable.me/hs-earth-science/key-terms/lunar-highlands#term","name":"lunar highlands","description":"Lunar highlands are the Moon's older, lighter-colored, heavily cratered regions. 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