Earth, our planet is the only planet in the universe that has life due to the presence of water and oxygen. Our home Earth is the third planet from the sun and the fifth largest amongst the 8 planets in our solar system.
How far is Earth from the sun?
The estimated distance of planet Earth from the Sun is about 93 million miles or 150 million kilometers. The distance from Earth to the sun is measured in terms of an astronomical unit or AU, which is used to measure the distances through the Solar System. However, the distance between Earth and Sun doesn’t remain constant, because Earth moves around the sun in its orbit which is elliptical or slightly oval-shaped. So, NASA has revealed that in due course of the calendar year sometimes Earth is closer to the sun and sometimes farther away from the sun.
What is Gravity?
Gravity is essentially a force that draws objects to its center. The gravity of the sun keeps all the planets of our solar system in their orbit. The planets that are closer to the sun experience more gravitational pull and those that are farther away have lesser effects of gravity. This is because gravity gets weaker with distance.
Each planet has its own gravity and even the moon & asteroids have gravity, based on their density, size, mass, and distance to other celestial objects.
Even the revolution of the moon around Earth is due to gravitation force. The gravitation pull of the moon causes high and low ocean tides on Earth.
Stars- a part of our Solar System
The twinkly stars that you see at night are actually huge celestial bodies made of hydrogen and helium that produce heat and light due to the nuclear reaction in their core. Stars are a part of the galaxy. Our solar system lies in the Milky Way galaxy and this alone has 300 billion stars.
Some stars appear to shine brighter than others and there are several factors behind this phenomenon. The brightness or luminosity of a star depends on how much energy it is spending on the illuminating effect and at what distance is it from Earth. Stars that far away appear to be less twinkly, than those closer to the Earth.
Under the clear night sky when you gaze up, the stars seem to be arranged in a sort of pattern. The pattern of stars that you notice are called constellations. Officially astronomers have identified 88 constellations and most of them appear as animals or mythical characters. The most popular constellation is Orion, as it is visible from any place on Earth.
The Earth rotates on its axis and this 24-hour cycle causes day and night. We also know that Earth revolves around the sun and takes about 365 days to complete one full round in its orbit. During the day the sun appears at different positions in the sky and it was rises in the East and sets in the West.
Earth’s Movement Brings About Changes in Seasons
Earth is slightly tilted at a 23.5-degree axis, this means one part of Earth is more exposed to the sun’s rays than the other. The part of Earth which is away from the sun experiences cool or winter season, and the part titled towards the sun experiences summer season. Therefore, when it is winter in the Northern hemisphere, it is summer in the Southern hemisphere. So when it is winter in North America, it is summer in Australia- which lies in the Southern hemisphere.
The Phenomena of Day and Night
When we say that the sun rises in the East and slowly moves towards the west, where it sets, it doesn’t mean that the sun is actually moving. It only appears that way because of Earth’s 24-hour rotation. The part of Earth which is exposed to the sun experiences daylight and the other part experiences night. So, when it is sunny in Indonesia, it is night in New York.
Hydrosphere, Atmosphere, and Biosphere
Hydrosphere refers to all the forms of water on Earth. It encompasses water in oceans, lakes, streams, rivers, seas, glaciers, and even water below the surface of the Earth. Plants, animals, and humans require water for survival. Water makes about 71% of the Earth’s surface, however only 0.5% is usable water and hence, water conservation is an important topic to be addressed.
The atmosphere is a layer of air that surrounds Earth and is made up of 14 gases. Weather occurs in the lower atmosphere which is referred to as the troposphere. The ozone layer is present in the stratosphere and is responsible for absorbing the harmful Ultra Violet (UV) rays of the sun. Pollution is rapidly causing the ozone layer to deplete and hence every effort should be made by mankind to reduce the harmful release of pollutants into the atmosphere.
The biosphere is where all organisms, plants, humans, and animals live. All organisms that live three meters below the ground and thirty meters above it are considered a part of the Biosphere.
Carolina’s Building Blocks of Science® 3D: Earth and Space Systems (©2019)
This kit is designed by Carolina for Grade 5 students and consists of 5 lessons, that can be taught in 22 sessions. Along with theoretical knowledge about space, universe, Earth, and sun, children actually use 3D models and practice hands-on learning experiences. IB Schools in Dubai across the Middle East encourage research-based and project-based studies, as it promotes greater retention amongst youngsters.
Summary of the 5 Lessons
Lesson 1: Children are encouraged to conduct research on the 8 planets in our solar system and make posters to showcase their diameter, distance, from the sun, and other important dimensions. They learn about the shape of the Earth and its movement around the sun.
Lesson 2: How does Earth interact with other objects in space? Students make models to investigate why some stars twinkle brighter than others and how they form patterns in the night sky and their position.
Lesson 3: With the help of models, children learn about the phases of the moon and how it affects the tidal pattern on Earth.
Lesson 4: Students are encouraged to work out models and make charts representing the Earth’s major systems of hydrosphere, atmosphere, and biosphere, and make a graph showing the distribution of water on Earth.
Lesson 5: Students perform group activities and research the positive and negative impacts of humans on the environment. They also enlist different measures that communities can undertake to protect natural resources.