science

Meteoritics

Meteoritics is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Meteoritics rather than just read about it. In short: Meteoritics is the science that deals with meteors, meteorites, and meteoroids. It is closely connected to cosmochemistry, mineralogy and geochemistry.

Key takeaways

Meteoritics belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Meteoritics to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Meteoritics from memory before moving on to harder problems.

Reference excerpt

Meteoritics is the science that deals with meteors, meteorites, and meteoroids. It is closely connected to cosmochemistry, mineralogy and geochemistry. A specialist who studies meteoritics is known as a meteoriticist. Scientific research in meteoritics includes the collection, identification, and classification of meteorites and the analysis of samples taken from them in a laboratory. Typical analyses include investigation of the minerals that make up the meteorite, their relative locations, orientations, and chemical compositions; analysis of isotope ratios; and radiometric dating. These techniques are used to determine the age, formation process, and subsequent history of the material forming the meteorite. This provides information on the history of the Solar System, how it formed and evolved, and the process of planet formation.

History of investigation

Before the documentation of L'Aigle it was generally believed that meteorites were a type of superstition and those who claimed to see them fall from space were lying. The only entry of a large meteoroid into Earth’s atmosphere in modern history with firsthand accounts was the Tunguska event of 1908. In 1960 John Reynolds discovered that some meteorites have an excess of 129Xe, a result of the presence of 129I in the solar nebula.

Methods of investigation

Mineralogy The presence or absence of certain minerals is indicative of physical and chemical processes. Impacts on the parent body are recorded by impact-breccias and high-pressure mineral phases (e.g. coesite, akimotoite, majorite, ringwoodite, stishovite, wadsleyite). Water bearing minerals, and samples of liquid water (e.g., Zag, Monahans) are an indicator for hydrothermal activity on the parent body (e.g. clay minerals).

Radiometric dating Radiometric methods can be used to date different stages of the history of a meteorite. Condensation from the solar nebula is recorded by calcium–aluminium-rich inclusions and chondrules. These can be dated by using radionuclides that were present in the solar nebula (e.g. 26Al/26Mg, 53Mn/53Cr, U/Pb, 129I/129Xe). After the condensed material accretes to planetesimals of sufficient size melting and differentiation take place. These processes can be dated with the U/Pb, 87Rb/87Sr, 147Sm/143Nd and 176Lu/176Hf methods. Metallic core formation and cooling can be dated by applying the 187Re/187Os method to iron meteorites. Large scale impact events or even the destruction of the parent body can be dated using the 39Ar/40Ar method and the 244Pu fission track method. After breakup of the parent body meteoroids are exposed to cosmic radiation. The length of this exposure can be dated using the 3H/3He method, 22Na/21Ne, 81Kr/83Kr. After impact on earth (or any other planet with sufficient cosmic ray shielding) cosmogenic radionuclides decay and can be used to date the time since the meteorite fell. Methods to date this terrestrial exposure are 36Cl, 14C, 81Kr.

Illustrations

Worked examples

Example 1 — a first encounter with Meteoritics

Start with the simplest possible case. Write down what Meteoritics claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Meteoritics before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Meteoritics ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Meteoritics

In research: Meteoritics appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Meteoritics in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Meteoritics is common in secondary-school and first-year university syllabi. It links to neighbouring topics Meteorites, Meteoroids, so understanding it makes those chapters shorter.
In everyday life: Look for Meteoritics outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Meteoritics in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Meteoritics means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Meteoritics out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Meteoritics in simple terms?

Meteoritics is the science that deals with meteors, meteorites, and meteoroids. It is closely connected to cosmochemistry, mineralogy and geochemistry.

Why does Meteoritics matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Meteoritics?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Meteoritics.