The Solar System: Sun and Galaxy

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Questions and Answers

What is the approximate percentage of the solar system's mass that the Sun contains?

99.8% (correct)

97.2%

85%

75%

What process is responsible for the Sun's brightness?

Combustion of helium

Thermal radiation from cooled iron

Nuclear fusion of hydrogen (correct)

Chemical reactions involving oxygen

At what speed does the light from the Sun travel to reach the Earth?

150,000 km/sec

300,000 km/sec (correct)

500,000 km/sec

100,000 km/sec

What is the main reason that all the planets and celestial objects are held together in the solar system?

Strong pull of the Sun's gravity Signup and view all the answers

How many times larger is the Sun's diameter compared to Earth's diameter?

Which planet is not listed as one of the eight planets from the Sun in the content?

Pluto Signup and view all the answers

What is the average amount of solar energy received by Earth?

174W/m^2 Signup and view all the answers

Which of the following is NOT a reason for Earth's suitability for life?

Abundance of nitrogen Signup and view all the answers

What is the average temperature of Earth?

15°C Signup and view all the answers

Which of the following is a misconception about Earth’s habitability?

It is the smallest planet in the solar system Signup and view all the answers

What essential feature does Earth's gravity provide?

It keeps the atmosphere in place Signup and view all the answers

What phenomenon demonstrates the elliptical shape of the Earth's shadow during a lunar eclipse?

The Eclipse of the Moon Signup and view all the answers

Which historical voyage is famously known for proving that the Earth is spherical?

Ferdinand Magellan's Voyage Signup and view all the answers

How does the Pole Star help demonstrate the shape of the Earth?

Its altitude changes based on location on Earth. Signup and view all the answers

What observation from the shore illustrates the curvature of the Earth?

A ship's mast appearing before the deck Signup and view all the answers

Which experiment is cited as the most convincing proof of the Earth's shape?

The Bedford Canal Experiment Signup and view all the answers

What does the circumnavigation by sailors indicate about the Earth's shape?

The Earth has a continuous curvature Signup and view all the answers

What is the polar diameter of the Earth?

12,714 km Signup and view all the answers

Which of the following statements about the Earth's atmosphere is true?

It is essential for life. Signup and view all the answers

Where does the biosphere extend?

From the highest mountain peaks to the deepest ocean trenches Signup and view all the answers

What is the shape of the Earth called?

Oblate Spheroid Signup and view all the answers

What are the primary components of Earth's atmosphere?

Nitrogen and Oxygen Signup and view all the answers

What is the equatorial diameter of the Earth?

12,756 km Signup and view all the answers

Which portion of the atmosphere is inhabited by organisms?

Lower portion Signup and view all the answers

Which concept refers to the sum of all living matter on Earth?

Biosphere Signup and view all the answers

What is the primary reason for the higher temperature in the troposphere?

The presence of the atmosphere Signup and view all the answers

What is the global temperature in the troposphere?

15 degrees Celsius Signup and view all the answers

How does the temperature change at higher altitudes?

It decreases due to decreased energy from the atmosphere Signup and view all the answers

Why were astronauts stunned by the color of Earth from the Moon?

It was blue indicating presence of water Signup and view all the answers

Why does the temperature vary in different parts of the Earth?

Due to the presence of hills on the surface Signup and view all the answers

What role do mountain ranges play concerning the Sun’s rays?

They act as shields protecting the surface from the Sun's radiation Signup and view all the answers

What would the color of Earth have appeared if it were flat?

Brown Signup and view all the answers

Which of the following contributes to the unique shape of the Earth?

The Earth revolving on its axis Signup and view all the answers

Which experiment attempted to prove the Earth's rotation?

Bedford Canal Signup and view all the answers

Which galaxy does the Solar System belong to?

Milky Way Signup and view all the answers

What is the main source of heat and light for life on Earth?

Sun Signup and view all the answers

Which planet is not part of the eight main planets of the Solar System?

Pluto Signup and view all the answers

In which direction do all the planets revolve around the sun?

Anti-clockwise Signup and view all the answers

What is the narrow zone where all forms of life exist called?

Biosphere Signup and view all the answers

Which of the following resources is NOT essential for human survival?

Minerals Signup and view all the answers

Which is a characteristic of Earth that makes it unique in the Solar System?

Presence of surface water Signup and view all the answers

What characteristic of the Earth allows it to have a favourable environment for various forms of life?

Favourable environment Signup and view all the answers

What is the role of the Sun in ocean currents?

Driving currents Signup and view all the answers

Study Notes

The Earth as a Planet

The Earth is a unique planet in the solar system with the right conditions for life to exist
The Milky Way galaxy is the "bigger boss" of our solar system, a collection of stars, gas, and dust in a spiral shape
The Sun is the "Big Boss" of our solar system, containing almost 99.8% of the mass and giving us the power of life

The Sun as a Star

The Sun is the biggest member of the solar system, about 109 times bigger than the Earth
The Sun's diameter is approximately 1.392 million km, while the Earth's diameter is about 12,756 km
The Sun is bright due to nuclear reactions that convert hydrogen to helium
The energy from the Sun lights and heats the Earth, travelling at a speed of about 300,000 km/sec

The Solar System

The stars are large, hot, and mainly made up of very hot gases
The Sun is at the center of our solar system, and all the planets, including the Earth, move around the Sun in an orbit
The strong pull of the Sun's gravity holds the planets and celestial objects together

The Planets

There are eight planets from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune
The planets are important members of the solar system

Earth - A Unique Planet

The Earth is the only planet known to have conditions suitable for life
The Earth is neither too hot nor too cold, receiving just the right amount of heat from the Sun
The Earth is abundant in water, essential for the existence of life
The Earth is not too large or too small, with a size and density that produces the right amount of gravity to hold its atmosphere

The Shape of the Earth

The shape of the Earth is an oblate spheroid, slightly flattened at the poles and bulging at the equator
Evidence showing the shape of the Earth includes:
- The Circular Horizon
- The Eclipse of the Moon
- The Pole Star
- The Sighting of a Ship
- The Circumnavigation
- The Bedford Canal Experiment
The Earth's polar diameter is about 12,714 km, while the Equatorial diameter is about 12,756 km

The Biosphere

The biosphere is the sum of all life, all living matter on the Earth, including all living organisms
The biosphere provides a home for all living organisms and is essential for life to exist
The biosphere is a thin layer that stretches from the highest mountains peaks (over 8 km height) to the deepest ocean trench (about 11 km depth)

The Universe

The universe probably originated due to the Big Bang, which happened about 20 billion years ago
Our sun is a star and belongs to the Milky Way galaxy
The solar family holds together due to the strong gravitational pull of the sun

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Description

Learn about the Sun as the center of our solar system and the Milky Way galaxy that contains it. Explore their composition and role in our universe.