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First ideas: what meteorites are, where they come from, and how to tell them from ordinary rocks.

1. 1What is a meteorite?A meteorite is a piece of rock or metal from space that has fallen all the way to the ground. In this first lesson you will meet the three words that every space-rock explorer needs.
2. 2Shooting starsHave you ever seen a quick flash of light race across the night sky? That was a meteor. Let's find out what is really happening up there.
3. 3Where do meteorites come from?Meteorites are visitors from far away. Most come from a ring of rocks called the asteroid belt, and a few come from the Moon and Mars.
4. 4When a meteorite fallsWhat really happens when a space rock falls to the ground? The answer might surprise you.
5. 5Three kinds of meteoriteMeteorites come in three big families: stony, iron and stony-iron. Each one tells a different story about the asteroid it came from.
6. 6What do meteorites look like?Meteorites have a few special clues that can help you recognise them. Learning these clues is the first step to becoming a meteorite detective.
7. 7Meteorwrongs: rocks that fool peopleLots of people find a strange rock and hope it is a meteorite. Most turn out to be meteorwrongs. Learning about them makes you a much better detective.
8. 8Where are meteorites found?Meteorites fall all over the Earth, but they are much easier to find in some places than others.
9. 9Craters: when big rocks hitMost meteorites land quite gently, but every so often a much larger space rock hits the ground hard and blasts out a huge hole called an impact crater.
10. 10Looking after meteorites, and staying safeMeteorites are precious pieces of science. In this last beginner lesson you will learn how to treat them, and yourself, with care.

The journey through the air, falls and finds, the main families of meteorite and how they get their names.

1. 1The journey through the atmosphereEvery meteorite survived one of the most violent journeys in nature. Here we follow a meteoroid from the edge of space to the ground, step by step.
2. 2Falls and findsEvery meteorite is either a fall or a find. Knowing the difference helps explain why museums value some meteorites so highly.
3. 3Asteroids: the parent bodiesMeteorites are samples of asteroids, and asteroids are leftovers from the building of the planets. To understand meteorites, we first need to understand their parents.
4. 4Chondrites: the oldest rocksChondrites are the most common meteorites of all, and some of the most important rocks in science. They are almost unchanged leftovers from the birth of the Solar System.
5. 5Achondrites: rocks from melted worldsAchondrites are stony meteorites without chondrules. They come from worlds that melted, and many of them look surprisingly like volcanic rocks on Earth.
6. 6Iron meteorites and their hidden patternsIron meteorites are pieces of the metal cores of shattered asteroids. Cut one open and etch it, and many reveal a beautiful crystal pattern found nowhere else in nature.
7. 7Stony-irons: pallasites and mesosideritesStony-iron meteorites are rare mixtures of metal and rock. They include some of the most beautiful objects that fall from the sky.
8. 8Meteorites from the Moon and MarsA few hundred meteorites are pieces of the Moon or Mars. How do we know, and what can they tell us?
9. 9Meteor showers and cometsMeteor showers are the most reliable shows in the night sky. They come from comets, and they teach us a lot about how meteors and meteorites differ.
10. 10How meteorites get their namesEvery officially recognised meteorite has a unique name. Learning how names work helps you read any meteorite label or catalogue.

Classification codes, carbonaceous and enstatite chondrites, iron groups, dating, and collecting responsibly.

1. 1Ordinary chondrites: H, L and LLRoughly four in every five meteorites seen to fall are ordinary chondrites. They are divided into three groups, H, L and LL, and learning to tell them apart is the first real step in classification.
2. 2Petrologic types: from wet to hotThe number after a chondrite's group letter, as in H5 or CM2, is its petrologic type. It tells you what happened to the rock inside its parent asteroid.
3. 3Carbonaceous chondritesCarbonaceous chondrites are rare, often dark and crumbly, and scientifically priceless. They carry water, organic molecules and the oldest solids in the Solar System.
4. 4Enstatite chondrites and other rare classesBeyond ordinary and carbonaceous chondrites lie smaller classes formed in very different chemical conditions. They show how varied the early Solar System was.
5. 5Shock and weathering gradesClassification codes often end with an S and a W number, as in L6 S4 W1. These record what impacts did to the rock in space, and what Earth did to it afterwards.
6. 6Iron meteorite groupsStructure tells you what an iron meteorite looks like when etched, but chemistry tells you which parent body it came from. Here you will learn both systems.
7. 7Fireball networks: from sky to orbitWhen a fireball is filmed from several places at once, scientists can find where its meteorites landed and trace where they came from in space.
8. 8How meteorites are datedMeteorites carry several clocks at once. Read correctly, they tell us when a rock formed, when it was knocked off its parent body and when it landed on Earth.
9. 9Identifying a possible meteoriteMost suspected meteorites turn out to be Earth rocks. This lesson sets out a careful, non-destructive approach, and explains what only a laboratory can confirm.
10. 10Collecting responsibly: ethics and the lawMeteorites are scientific specimens, cultural objects and sometimes legally protected property. Responsible hunters and collectors know the rules and help science.

Oxygen isotopes, early Solar System chronology, parent bodies, sample return and classifying a new meteorite.

1. 1The classification frameworkMeteorite classification is a hierarchy built on petrology, bulk chemistry and isotopes. This lesson sets out the modern framework that every later lesson refers back to.
2. 2Oxygen isotopes: the fingerprint of originOxygen makes up nearly half of most rocks by mass, and its three stable isotopes carry a signature that distinguishes parent bodies. Oxygen isotopes are among the most powerful tools in classification.
3. 3The NC–CC isotopic dichotomyNucleosynthetic isotope anomalies split meteorites into two great families that formed in separate regions of the disc. This discovery reshaped ideas about Jupiter and planet formation.
4. 4Early Solar System chronologyMeteorites let us build a timeline of the first few million years of the Solar System with a precision that seems almost impossible. Here is how it is done.
5. 5Delivery: from asteroid families to EarthWhich asteroids are our meteorites actually coming from? Dynamics, spectroscopy and exposure ages are converging on answers.
6. 6Primitive achondrites and ureilitesBetween chondrites and fully melted achondrites lie rocks caught in the act of melting. They reveal how differentiation begins.
7. 7Iron meteorites: cores, cooling and dynamosIron meteorites preserve quantitative records of how asteroid cores crystallised and cooled, and even whether they generated magnetic fields.
8. 8Martian meteorites in depthMartian meteorites are our only samples of Mars. Their petrology, ages and isotopes reveal the planet's volcanic history, water and atmosphere.
9. 9Sample return: ground truth for meteoriticsSamples collected directly from known bodies test the links that meteoriticists have proposed for decades, and reveal what meteorites alone cannot.
10. 10Classifying a new meteoriteThis final lesson brings the course together, following a new meteorite from arrival at the laboratory to an approved name in the Meteoritical Bulletin.