science

Messier (crater)

Messier (crater) 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 Messier (crater) rather than just read about it. In short: Messier is a relatively young lunar impact crater located on the Mare Fecunditatis. To Earth observers, they appear similar in size, form, depth, and brightness.

Key takeaways

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

Reference excerpt

Messier is a relatively young lunar impact crater located on the Mare Fecunditatis. To Earth observers, they appear similar in size, form, depth, and brightness. The crater has a discernible oblong shape that is not caused by foreshortening. The longer dimension is oriented in an east–west direction. Just to the west lies Messier A, a similar-sized crater with an oblong, doublet form. The longer dimension of this crater is oriented north–south, at right angles to Messier. This crater also has a curved bulge extending to the west. Messier and Messier A were photographed at high resolution by NASA's Lunar Orbiter 5 spacecraft In August 1967. The Lunar Orbiter V_041 image is archived at the Lunar and Planetary Institute website. The Lunar Orbiter V partial image shown here is derived from the Lunar Orbiter Image Recovery Project effort to reprocess these images from the original tapes. The interiors of Messier and Messier A have a higher albedo than the surrounding mare. There is also a dark streak in the center of each crater. Two prominent, nearly linear rays extend westwards from the rim of Messier A, continuing over 100 kilometers towards the west edge of Mare Fecunditatis. The mare surface around the craters is also lightly marked by rays from other craters. It is theorized that Messier crater was formed by an impact at a very low angle, and that Messier A could have formed following a rebound by the impacting body. The low angle of impact may also explain the asymmetrical ray system. To the northwest of Messier A is a long, narrow rille, called Rima Messier. This crater is named in honor of the French astronomer Charles Messier (1730–1817).

Satellite craters By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Messier.

The following crater has been renamed by the IAU.

Messier G - See Lindbergh (crater). Messier A has been called W. H. Pickering, but this was never officially sanctioned by the IAU. A different crater has since been named for Pickering.

Gallery

References

Sources

External links http://messier.seds.org/xtra/m-crater.html Charles A. Wood. Messier on the Moon. Sky & Telescope, August 1, 2006

Illustrations

Worked examples

Example 1 — a first encounter with Messier (crater)

Start with the simplest possible case. Write down what Messier (crater) 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 Messier (crater) 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 Messier (crater) 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 Messier (crater)

In research: Messier (crater) 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 Messier (crater) 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: Messier (crater) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Impact craters on the Moon, LQ21 quadrangle, so understanding it makes those chapters shorter.
In everyday life: Look for Messier (crater) 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 Messier (crater) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Messier (crater) 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 Messier (crater) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Messier (crater) in simple terms?

Messier is a relatively young lunar impact crater located on the Mare Fecunditatis. To Earth observers, they appear similar in size, form, depth, and brightness.

Why does Messier (crater) 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 Messier (crater)?

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 Messier (crater).