Bài mở: Solar System

SOLAR SYSTEM
Can you name the planets in order from the sun?
Planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
I. Solar system
The Solar System consists of the Sun and the astronomical objects bound to it by gravity, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. Of the many objects that orbit the Sun, most of the mass is contained within eight relatively solitary planets whose orbits are almost circular. The four smaller inner planets, Mercury, Venus, Earth and Mars, also called the terrestrial planets, are primarily composed of rock and metal. The four outer planets, the gas giants, are substantially more massive than the terrestrials. The two largest, Jupiter and Saturn, are composed mainly of hydrogen and helium; the two outermost planets, Uranus and Neptune, are composed largely of ices, such as water, ammonia and methane, and are often referred to separately as "ice giants".
II. Sun
● The Sun is the star at the center of the Solar System. It is a near-perfect sphere. The mass of the sun larger than 332.900 times the mass of the Earth, and its mass accounts for about 99.86% of the total mass of the Solar System. It has a diameter of about 1,392,000 km, about 109 times that of Earth.
● The Sunlight support for most life on Earth through photosynthesis, and control climate as well as weather on Earth.
● The composition of the Sun consists of hydrogen, helium, and small amounts of other elements.

III. Planets
1. Mercury
● Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun.
● The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt.
● Mercury is bright when viewed from Earth.
● Mercury doesn’t have any natural satellites.
● Surface temperatures range from about −183°C to 427°C.
● Diameter: 4,880 km
● Orbital Period: 88 days
● Planet day: 1400 hours

2. Venus
● Venus is the second planet from the Sun.
● After the Moon, it is the brightest natural object in the night sky. Venus reaches its maximum brightness shortly before sunrise or shortly after sunset, for which reason it has been known as the Morning Star or Evening Star.
● Venus has the densest atmosphere of all the terrestrial planets in the Solar System, consisting mostly of carbon dioxide.
● Venus has a relatively flat surface - more than 90% of the surface of Venus is covered with lava.
● Surface temperature of Venus is about 464°C.
● Diameter: 12,103 km
● Orbital Period: 220 days
● Planet day: 5,800 hours
3. Earth (The Earth)
● Earth (or the Earth) is the third planet from the Sun, and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System`s four terrestrial planets.
● It is sometimes referred to as the World, the Blue Planet, or by its Latin name, Terra.
● Home to millions of species, including humans, Earth is the only place in the universe where life is known to exist. The planet formed 4.54 billion years ago, and life appeared on its surface within one billion years.
● Diameter: 12,756 km
● Orbital Period: 365 days
● Planet day: 24 hours
4. Mars
● Mars is the fourth planet from the Sun in the Solar System. It is often described as the "Red Planet“.
● Mars is a terrestrial planet with a thin atmosphere composed mainly CO2.
● Its surface has many craters, volcanoes and valleys.
● Mars has Olympus Mons, the highest known mountain within the Solar System, and Valles Marineris, the largest canyon.
● Mars surface temperatures vary from lows of about −87°C during the polar winters to highs up to −5°C in summers.
● Diameter: 6,794 km
● Orbital Period: 2 years
● Planet day: 25 hours
5. Jupiter
● Jupiter is the fifth planet from the Sun and the largest planet within the Solar System.
● Jupiter is a gas giant planet, formed mainly by hydrogen and helium.
● Jupiter is a great planet, more than twice the weight of all seven remaining planets of the Solar System combined.
● Jupiter is the third-brightest object in the night sky after the Moon and Venus.
● The best known feature of Jupiter is the Great Red Spot, a persistent anticyclonic storm that is larger than Earth. It is known to have been in existence since at least 1831, and possibly since 1665.
● Diameter: 142,984 km
● Orbital Period: 12 years
● Planet day: 10 hours
6. Saturn
● Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter.
● The second largest after Jupiter, but Saturn`s mass is less than 1/3 the mass of Jupiter. This is also the lightest planet in the Solar System.
● Saturn is the planet for many land and air, gas, and cold, but with the warm colors of the adjacent satellites.
● Saturn is prominent because a lot of colored rings around the equator.
● The temperatures on Saturn are normally −185°C.
● Saturn has at least 62 moons.
● Diameter: 120,536 km
● Orbital Period: 30 years
● Planet day: 10 hours
7. Uranus
● Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System.
● It is the coldest planetary atmosphere in the Solar System, with a minimum temperature of –224°C.
● Like the other giant planets, Uranus has a ring system. Uranus has a faint rings are made of stones with a diameter of about 10 m, but the fact that this ring consists of many small rings.
● Diameter: 51,118 km
● Orbital Period: 84 years
● Planet day: 17 hours
8. Neptune
● Neptune is the eighth and farthest planet from the Sun in the Solar System.
● It is the fourth-largest planet by diameter and the third-largest by mass.
● While Jupiter has Great Red Spot and Saturn has Great White Spot, Neptune has Great Dark Spot. It is a giant tornado.
● Because of its great distance from the Sun, Neptune`s outer atmosphere is one of the coldest places in the Solar System, with temperatures at its cloud tops approaching −218°C.
● Diameter: 49,532 km
● Orbital Period: 160 years
● Planet day: 16 hours
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