Grade 9 Applied Science – Space

The Night Sky

Section 8.1 Pages 292-296 and Section 8.3 Pages 301-304

asteroids / Astronomical Unit / celestial object
dinosaurs / dirty snowballs / dust
eight / friction / gas
gas giants / light-years / luminous
mass / natural satellite / Neptune
orbit / reflect / rock
shooting stars / stars / Sun
sun spots / surface / terrestrial planets

Any object in space (e.g., sun, moon, planets, comets) is a ______. You and I mostly see ______. Why? Stars give off light (i.e., stars are ______). Within our Solar System, we can also see five of the planets because the planets ______light.

A star is a massive collection of ______in space that emits large amounts of energy. The stars appear as small dots in the night sky because they are many, many, many kilometers away. In the Universe, the distance is measured in ______or the distance light travels in one year. That distance is 9.4605284 x 1012 kilometers (i.e., 9 460 528 400 000 km). Recall, Toronto is about 300 kilometers or 3.0 x 102 kilometers from Kingston.

The ______is a star. The Sun is massive. It is 1.4 million kilometers in diameter (about 110X greater than Earth’s diameter) with a ______330 000X larger than the Earth. At its core, the Sun’s temperature is 15 000 000OC. Yet at the Sun’s photosphere (near the surface of the Sun), the temperature is only about 6 000 OC, and around the corona, the bright area around the Sun, the temperature is nearly 1,000,000 OC. Cool areas seen on the Sun’s surface are called ______. Our Sun is 1.5 x 108 km (150 000 000 km) from Earth. This distance is called an ______(AU). Inside our solar system, AUs are used to measure distances. For example, the planet Jupiter is 5.2 AU from the Sun. That means, Jupiter is 5.2 AU further away from the Sun than the Earth.

In our Solar System, there are ______planets classified in two groups.

1.  ______are composed of mostly ______. These planets are Mercury, Venus, Earth and Mars. Since these planets are solid, they are also called the ______.

2.  The outer plants which are very large planets consisting mostly of gas. The outer planets are Jupiter, Saturn, Uranus and ______. These four planets are also called the ______.

A planet is a large, round celestial object that travels around a star is a closed or continuous path called an ______. To be classified as a planet, a celestial object must (1) orbit only one star, (2) contain enough mass so that its gravity pulls the planet into a round or spherical shape, and (3) possess the ability to clear other celestial objects out of its orbit. Pluto is not a planet because it orbits both the Sun and Neptune.

Other Solar Bodies

A celestial object that orbits a larger celestial object is called a ______. Since the Moon orbits Earth, it is a natural satellite of Earth.

______are minor planets ranging in size from 1 m to over 100 km. They are small, irregular shaped rocks. There are millions inside our Solar System. It is believed that a gigantic asteroid collided with Earth to form the Moon over 4.5 billion years ago, and another large asteroid collided with Earth about 65 million years ago causing catastrophic climate change resulting in the extinction of the ______.

There are billions and billions of comets in the Solar System. Consisting mostly of ice and ______, they are also called ______. When pulled by Sun’s gravity, materials on the surface evaporate, and then, they are pushed away from the comet by solar winds. This is seen as the tail that follows the comet. The tail always points away from the Sun.

Meteors and meteorites are dust and rock fragments from space that enter Earth’s atmosphere. A meteor is caused by the ______between the fragment and the atmosphere. It caused the particles to heat up and vaporize. This is visible, and we call it ______. A meteorite is a large fragment that gets through the atmosphere and strikes the Earth’s ______.
ANSWERS

Any object in space (e.g., sun, moon, planets, comets) is a ______< celestial object >. You and I mostly see ______< stars >. Why? Stars give off light (i.e., stars are ______< luminous >). Within our Solar System, we can also see five of the planets because the planets ______< reflect > light.

A star is a massive collection of ______< gases > in space that emits large amounts of energy. The stars appear as small dots in the night sky because they are many, many, many kilometers away. In the Universe, the distance is measured in ______< light-years > or the distance light travels in one year. That distance is 9.4605284 x 1012kilometers (i.e., 9 460 528 400 000 km). Recall, Toronto is about 300 kilometers or 3.0 x 102 kilometers from Kingston.

The ______< Sun > is a star. The Sun is massive. It is 1.4 million kilometers in diameter (about 110X greater than Earth’s diameter) with a ______< mass > 330 000X larger than the Earth. At its core, the Sun’s temperature is 15 000 000OC. Yet at the Sun’s photosphere (near the surface of the Sun), the temperature is only about 6 000 OC, and around the corona, the bright area around the Sun, the temperature is nearly 1,000,000 OC. Cool areas seen on the Sun’s surface are called ______< sun spots >. Our Sun is 1.5 x 108 km (150 000 000 km) from Earth. This distance is called an ______< Astronomical Unit > (AU). Inside our solar system, AUs are used to measure distances. For example, the planet Jupiter is 5.2 AU from the Sun. That means, Jupiter is 5.2 AU further away from the Sun than the Earth.

In our Solar System, there are ______< eight > planets classified in two groups.

1.  ______< inner planets > which are composed of mostly ______< rock >. These planets are Mercury, Venus, Earth and Mars. Since these planets are solid, they are also called the ______< terrestrial planets >.

2.  The outer plants which are very large planets consisting mostly of gas. The outer planets are Jupiter, Saturn, Uranus and ______< Neptune >. These four planets are also called the ______< gas giants >.

A planet is a large, round celestial object that travels around a star is a closed or continuous path called an ______< orbit >. To be classified as a planet, a celestial object must (1) orbit only one star, (2) contain enough mass so that its gravity pulls the planet into a round or spherical shape, and (3) possess the ability to clear other celestial objects out of its orbit. Pluto is not a planet because it orbits both the Sun and Neptune.

Other Solar Bodies

A celestial object that orbits a larger celestial object is called a ______< natural satellite >. Since the Moon orbits Earth, it is a natural satellite of Earth.

______< asteroids > are minor planets ranging in size from 1 m to over 100 km. They are small, irregular shaped rocks. There are millions inside our Solar System. It is believed that a gigantic asteroid collided with Earth to form the Moon over 4.5 billion years ago, and another large asteroid collided with Earth about 65 million years ago causing catastrophic climate change resulting in the extinction of the ______< dinosaurs >.

There are billions and billions of comets in the Solar System. Consisting mostly of ice and ______< dust >, they are also called ______< dirty snowballs >. When pulled by Sun’s gravity, materials on the surface evaporate, and then, they are pushed away from the comet by solar winds. This is seen as the tail that follows the comet. The tail always points away from the Sun.

Meteors and meteorites are dust and rock fragments from space that enter Earth’s atmosphere. A meteor is caused by the ______< friction > between the fragment and the atmosphere. It caused the particles to heat up and vaporize. This is visible, and we call it ______< shooting stars >. A meteorite is a large fragment that gets through the atmosphere and strikes the Earth’s ______< surface >.