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Moon - a natural satellite. Moon - the best-studied extra-terrestrial object

Source: licencja: CC 0.

Księżyc – naturalny satelita. Księżyc – najlepiej zbadany obiekt pozaziemski

You will learn

- recognize the Moon as a natural satellite of the Earth,
- to describe the motion of the Moon around the Earth.

Before you start, answer the question.

  • What do you know about the Moon?

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nagranie abstraktu

The Moon is the natural satellitenatural satellitenatural satellite of the Earth. Its mean distance from the Earth is 384405 km. There is no water, and practically no atmosphere on the Moon.

Natural satellite 
Definition: Natural satellite 
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nagranie abstraktu

natural satellitenatural satellitenatural satellite is any celestial body that orbits around another larger object. A natural satellite orbiting planets are called moons.

Orbital period
Definition: Orbital period
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nagranie abstraktu

The Moon orbits the Earth. If we measure the motion of the Moon around the Earth in relation to the distant stars then we speak of the sidereal period of its revolution. The moon moves completely around the celestial sphere in about 27,3 days as observed from the Earth.

If the motion of the Moon is consider relative to the Sun then we speak of the synodic period. The synodic period is the time required to return to the same position relative to the Sun as seen by an observer on the Earth (i.e. time between the same moon phases). The synodic period is 29,5 days.

Orbit
Definition: Orbit
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nagranie abstraktu

The Moon revolves around Earth in an ellipticalellipticalelliptical orbit which is tilted of about 5⁰ in respect to the Earth’s orbitorbitorbit. Hence, the Moon's centre‑to‑centre distance from the Earth varies with mean values of 363396 km at perigeeperigeeperigee to 405504 km at apogeeapogeeapogee.

Perigee
Definition: Perigee
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nagranie abstraktu

PerigeeperigeePerigee is the point in the orbitorbitorbit of the Moon at which it is closest to the Earth.

Apogee
Definition: Apogee
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nagranie abstraktu

ApogeeapogeeApogee is the point in the orbitorbitorbit of the Moon at which it is furthest from the Earth.

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Ilustracja przedstawia Słońce, wokół którego po orbicie, oznaczonej numerem 2, krąży Ziemia oraz orbitę Księżyca, oznaczoną numerem 1, krążącego wokół Ziemi. Na ilustracji widoczne są numery, a na nich podpisy. 1. orbit of the Moon {audio}, 2. orbit of the Earth {audio}.
Orbits of the Earth and Moon
Source: GroMar, licencja: CC BY 3.0.
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Parameters describing the orbits of the Earth and Moon
Source: GroMar, licencja: CC BY 3.0.

The figure shows the mutual position of the orbits of the Moon and the Earth. The axes of the Earth and the Moon are inclined to the planes of their orbits. The angle between the orbital planes of the Earth and the Moon is called inclination.

Surface of the Moon

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nagranie abstraktu

The surface of the Moon is covered with the dark and light areas. The dark areas are called maria. They cover about 17% of the Moon’s surface. The place where for the first time the astronauts landed is Mare Tranquilitatis (Sea of Tranquillity). The maria are large, dark, basaltic plains formed by ancient volcanic eruptions. Early astronomers were convinced that they are seas (Latin; singular: mare, plural: maria). The light areas between maria, highlands, are covered by large number of impact and volcano craters, lava, and mountains. Highlands have no names, but the craters are named for famous figures in the history of science.

Selenography
Definition: Selenography
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nagranie abstraktu

SelenographyselenographySelenography is introduced by Galileo, is the study of the surface and physical features of the Moon.

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Source: GroMar, licencja: CC BY 3.0.
Task 1
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nagranie abstraktu

Search in the internet and find:

1. some examples of lunar seas,

2. what the largest crater on the Moon is.

Remember

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nagranie abstraktu
  • The Moon is a natural satellitenatural satellitenatural satellite of the Earth.

  • Moon revolves around Earth in an ellipticalellipticalelliptical orbit which is tilted of about 5⁰ in respect to the Earth’ orbitorbitorbit.

  • Its sidereal period is about 27,3 days and synodic is 29,5 days.

Exercises

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Exercise 1
Wersja alternatywna ćwiczenia: Determine which sentences are true. Możliwe odpowiedzi: 1. The Moon travel around the Earth in a circular orbit., 2. The moon reflects the light from the Sun., 3. The Moon’s orbit is tilted in respect to the Earth’s orbit., 4. Practically Moon has no atmosphere.
Exercise 2

What part of the Earth's diameter is the diameter of the Moon?

Exercise 3

Describe in English how the surface of the Moon looks like.

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Exercise 4
Wersja alternatywna ćwiczenia: Indicate which pairs of expressions or words are translated correctly. Możliwe odpowiedzi: 1. naturalny satelita - natural satellite, 2. okres orbitalny - orbital period, 3. perygeum - perigee, 4. apogeum - apogee, 5. wyżyna - tilt, 6. orbita - tilt
zadanie
Source: GroMar, licencja: CC BY 3.0.
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Interaktywna gra, polegająca na łączeniu wyrazów w pary w ciągu jednej minuty. Czas zaczyna upływać wraz z rozpoczęciem gry. Jeden ruch to odkrywanie najpierw jednej potem drugiej karty z wyrazem. Każdy wyraz jest odczytywany. Kolejny ruch to odkrywanie trzeciej i czwartej karty. W ten sposób odsłuchasz wszystkie wyrazy. Nawigacja z poziomu klawiatury za pomocą strzałek, odsłuchiwanie wyrazów enterem lub spacją. Znajdź wszystkie pary wyrazów.
Source: Zespół autorski Politechniki Łódzkiej, licencja: CC BY 3.0.

Glossary

natural satellite
natural satellite

naturalny satellita

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wymowa w języku angielskim: natural satellite
orbital period
orbital period

okres orbitalny

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wymowa w języku angielskim: orbital period
perigee
perigee

perygeum

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wymowa w języku angielskim: perigee
apogee
apogee

apogeum

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wymowa w języku angielskim: apogee
tilt
tilt

nachylenie

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wymowa w języku angielskim: tilt
selenography
selenography

selenografia

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wymowa w języku angielskim: selenography
highland
highland

wyżyna

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wymowa w języku angielskim: highland
elliptical
elliptical

eliptyczny

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wymowa w języku angielskim: elliptical
orbit
orbit

orbita

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wymowa w języku angielskim: orbit

Keywords

natural satellitenatural satellitenatural satellite

orbital periodorbital periodorbital period

perigeeperigeeperigee

apogeeapogeeapogee

tilttilttilt