Unit 6 The Earth and the Universe

Lesson 1 Our Solar System

The Sun and the eight planets are part of the Solar System. The nine planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. The Sun is in the center of the Solar System. All the eight planets move around the Sun in a large oval path. The planets also spin by itself.

The Sun is the star at the center of the Solar System. The Earth and other matter (including other planets, asteroids, meteoroids, comets, and dust) orbit the Sun, which by itself accounts for about 99.86% of the Solar System's mass.The mean distance of the Sun from the Earth is approximately 149.6 million kilometers (1 AU), and its light travels this distance in 8 minutes and 19 seconds. This distance varies throughout the year from a minimum of 147.1 million kilometers (0.9833 AU) on the perihelion (around 3 January), to a maximum of 152.1 million kilometers (1.017 AU) on the aphelion (around 4 July). Energy from the Sun, in the form of sunlight, supports almost all life on Earth via photosynthesis, and drives the Earth's climate and weather.
The Sun consists of hydrogen (about 74% of its mass, or 92% of its volume), helium (about 24% of mass, 7% of volume), and trace quantities of other elements, including iron, nickel, oxygen, silicon, sulfur, magnesium, carbon, neon, calcium, and chromium.

Asteroid

Asteroids, sometimes called minor planets or planetoids, are small Solar System bodies in orbit around the Sun, especially in the inner Solar System; they are smaller than planets but larger than meteoroids.

Asteroids are huge chunks of rocks that travel round the Sun.

Comets

A comet is a Small Solar System Body that orbits the Sun. When close enough to the Sun, a comet exhibits a visible coma (fuzzy "atmosphere"), and sometimes a tail, both because of the effects of solar radiation upon the comet's nucleus.

Comets have long glowing tails.

Halley's Comet or Comet Halley (officially designated 1P/Halley) is the most famous of the periodic comets and can currently be seen every 75–76 years.Many comets with long orbital periods may appear brighter and more spectacular, but Halley is the only short-period comet that is clearly visible to the naked eye, and thus, the only naked-eye comet certain to return within a human lifetime.Halley's Comet was the first comet to be recognized as periodic. Perceiving that the observed characteristics of a comet of 1682 were nearly the same as those of two comets which had appeared in 1531 (observed by Petrus Apianus) and 1607 (observed by Johannes Kepler), Edmond Halley perturbations concluded that all three comets were in fact the same object returning every 76 years (a period that has since been amended to every 75–76 years). After a rough estimate of the the comet would sustain from the attraction of the planets, he predicted its return for 1758.

The next predicted perihelion of Halley's Comet is July 28, 2061.

Meteors
A meteoroid is a sand- to boulder-sized particle of debris in the Solar System. The visible path of a meteoroid that enters Earth's (or another body's) atmosphere is called a meteor, or colloquially a shooting star or falling star.
Meteors are tiny rocks which probably come from the asteroid belt.

Lesson 2 How Far and How Big

Size	Ratio
Moon	1
Earth	4
Sun	400

Scientists have calculated that the Sun is one hundred times the size of Earth. Earth is four times the sizes of the Moon.

Distance from	Ratio
Earth to Moon	1
Earth to Sun	400

The distance from Earth to the Sun is 400 times the distance from Earth to the Moon.

Lesson 3 Planet, Planet How Are You ?

Mercury
It is too close to the Sun. The temperature is too hot to support life.

Venus
A great amount of the heat from the Sun is trapped in its atmosphere. This marks it hotter than Mercury.

Earth

It has water, air and a suitable temperature to support life.

Mercury, Venus, Earth and Mars are the four planets that are the nearest to the Sun. They are called the inner planets. All these planets are made of rocks. Each of the inner planet has an atmosphere. The atmosphere of Earth contains air which is suitable for living things to survive. The atmosphere of the other inner planets is very thin and poisonous to living things.

Jupiter

It is so big that all the other planets could fit inside it.

Saturn

Saturn has three wide rings. They can be seen with a telescope.

Uranus

Unlike the other planets, Uranus is lying on its side as it goes round the Sun.

Neptune

Neptune is covered with a blue ocean of liquid methane.

The outer planets are Jupiter, Saturn, Uranus, and Neptune . They are mainly made of gases. Their temperature is too cold to support life.

The position of Earth from the Sun is just right for it to receive enough heat to support life .It has water and air too .These are needed to support life .The other planets either receive too little or too much heat .They also do not have a suitable atmosphere for living to survive.

Planets in centimeters	Scaled data diameter
Mercury	1.5
Venus	4.5
Earth	4.5
Mars	5.0
Jupiter	50.0
Saturn	45.0
Uranus	15.0
Neptune	15.0

Term Used

English	Bahasa Melayu
Absence of air	-ketiadaan udara
Absence of water	-Ketiadaan air
atmosphere	-Atmosfera
Concentric circle	-bulatan sepusat
cooperate	-bekerjasama
design	-mereka bentuk
Earth	-Bumi
estimation	-anggaran
Jupiter	-Musytari
Mars	-Marikh
Mercury	-Utarid
Neptune	-Neptun
Pluto	-Pluto
poisonous	-beracun
puzzle	Teka-teki
sago	sagu
Saturn	Zuhal
Solar System	Sistem Suria
Support lives	Menyokong hidupan
Uranus	Uranus
Venus	Zuhrah