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Langrenus (crater)

Langrenus (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 Langrenus (crater) rather than just read about it. In short: Langrenus is an impact crater located near the eastern lunar limb. British astronomer T.

Langrenus (crater) — main illustration
Langrenus (crater) — illustration

Key takeaways

  • Langrenus (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 Langrenus (crater) to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Langrenus (crater) from memory before moving on to harder problems.

Reference excerpt

Langrenus is an impact crater located near the eastern lunar limb. British astronomer T. W. Webb calls it "a superb object under oblique sunshine, with its terraced ring." The feature is circular in shape, but appears oblong due to foreshortening. It lies on the eastern shore of the Mare Fecunditatis. To the south is the overlapping crater pair Vendelinus and the smaller Lamé. On the lunar geologic timescale, Langrenus is a crater of Eratosthenian age. The inner wall of Langrenus is wide and irregularly terraced, with an average width of about 20 kilometers. The outer ramparts are irregular and hilly, and there is a bright, fragmented ray system spread across the mare to the west. The interior of the crater has a higher albedo than the surroundings, so the crater appears bright when the Sun is overhead. The crater floor is covered by many boulders, and is slightly irregular in the northwest half. The central peaks rise about a kilometer above the floor, and a peak on the eastern rim ascends to an altitude of 3 km. The infrared spectrum of pure crystalline plagioclase has been identified on the central peak. On December 30, 1992, Audouin Dollfus of the Observatoire de Paris observed a series of glows on the floor of this crater using the one-meter telescope. These glows changed form with time, and Dollfus expressed the belief that this was likely a gaseous emission. The cracked floor of the crater may have been the source of the gas. Flemish astronomer Michael van Langren was the first person to draw a lunar map while giving names to many of the features, in 1645. He named this crater after himself; it is the only one of his named features that has retained his original designation.

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 Langrenus.

Many of the more significant associated craters that surround Langrenus have since been renamed by the IAU.

Langrenus A — See Barkla. Langrenus B — See Naonobu. Langrenus C — See Acosta. Langrenus D — See Al-Marrakushi. Langrenus F — See Bilharz. Langrenus J — See Somerville. Langrenus K — See Atwood.

References

Sources

External links

LAC-80 AS16-M-0666 view from Apollo 16 At the Top of the Avalanche, on the central peak of Langrenus, from LROC Wood, Chuck (November 25, 2007). "Moving Eastward". Lunar Photo of the Day. Retrieved 2015-11-08. Lights glow on Moon

Illustrations

Langrenus (crater) illustration
Langrenus (crater): This view is from Apollo 8, the first crewed mission to the Moon. During the mission, astronaut James Lovell described Langrenus as "quite a huge crater; it's got a central cone to it. The walls of the crater are terraced, about six or seven terraces on the way down."
This view is from Apollo 8, the first crewed mission to the Moon. During the mission, astronaut James Lovell described Langrenus as "quite a huge crater; it's got a central cone to it. The walls of the crater are terraced, about six or seven terraces on the way down."
Langrenus (crater): Crater location
Crater location
Langrenus (crater): Apollo 15 Mapping camera image
Apollo 15 Mapping camera image
Langrenus (crater): On the eastern edge of Mare Fecunditatis is the crater Langrenus, seen as the lighter grey area on the right-center of the photo.
On the eastern edge of Mare Fecunditatis is the crater Langrenus, seen as the lighter grey area on the right-center of the photo.

Worked examples

Example 1 — a first encounter with Langrenus (crater)

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

In research
Langrenus (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 Langrenus (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
Langrenus (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 Langrenus (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 Langrenus (crater) in 20 minutes

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

Frequently asked questions

What is Langrenus (crater) in simple terms?

Langrenus is an impact crater located near the eastern lunar limb. British astronomer T.

Why does Langrenus (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 Langrenus (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 Langrenus (crater).

Tags

  • Impact craters on the Moon
  • LQ21 quadrangle

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