Earth

EARTH: Features, Atmosphere, Orbit, Rotation, Humans on Earth!!

Table of Contents

Solar system
Image - Solar System

INTRODUCTION TO EARTH

The Earth is the third planet from the Sun and the only cosmic object known to support life. This is made possible by Earth’s oceanic environment, the only one in the Solar System with liquid surface water. The global ocean contains nearly all of Earth’s water, which covers 70.8% of the planet’s crust. Land makes up the remaining 29.2% of the Earth’s crust, the majority of which is in the form of continental landmasses inside the land hemisphere. Earth is the fifth largest planet of our solar system just behind four gas giants —Jupiter, Saturn, Uranus & Neptune —and head of other three rocky planets Mercury, Mars and Venus.

Earth
Image - Planet Earth

PLANET FEATURES

Earth Facts

  • Equator circumference: 40,075km
  • Radius: 6,371km
  • Average distance from Sun: 149 million km/ 1 astronomical units (AU)
  • Surface temperature: 15°C
  • Surface gravity: 9.80665 m/s2 or 1 g0
  • Surface area: 5.1007 X 108 Km2
  • Volume: 1.08321 X 1012 Km3
  • Mass: 5.972 X 1024 Kg
  • Escape Velocity: 11.186 m/s
  • Mean density: 5.513 g/cm3
  • Day length: 1 Earth days (23 Hour 56 Minutes 4 Seconds)
  • Year length: 365.25 Earth days
  • Sunlight travel time: 8.33 Minutes
  • Average orbital speed: 66,620 mph (29.78km/s)
  • Moons: 1
  • Planet type: terrestrial
  • Composition: Nitrogen, Oxygen, Water vapor, Carbon dioxide, Neon, Argon, Helium, Methane, Krypton, Hydrogen,
Aphelion and Perihelion Position of Earth Respect to the Sun
Axial Tilt (23.5°) of Earth

EARTH'S ORBIT, ROTATION & AXIS TILT

  • Orbital Path: Earth orbits the sun with an average distance of 149.6 million kilometres (92.96 million miles) in counter clockwise. To complete one orbit Earth takes 365 days 6 hours and 9 minutes, during this time Earth has traveled around 940 million kilometres (584 million miles). Over this time, Earth travels at a speed of 108,000km/h (67,000 mph) around the Sun.
  • Rotation & Revolution: In addition to orbiting the Sun, the Earth spins on an axis that runs through the North and South Poles, resulting in day and night. As we know from our school that Earth doesn’t spinning around its polar axis at a right angle. Instead, the axis is slightly tilted over by the rotation speed is 1670 km/h (1030 mph).
  • Changing of the Seasons: We know that, it has near about 5 million km (3 million miles) difference between Earth’s closest point to the sun (Perihelion) and the furthest point (Aphelion). But it is not the actual reason having different season. The seasons are caused by the Earth’s 23.5° tilt and how it influences the amount of sunlight that reaches our planet from the sun. To demonstrate, let’s start with the North Pole tilting 23.5° towards the Sun and the South Pole tilting completely away from it. The northern hemisphere is receiving a big dose of sunlight, and the day this occurs is the longest day of summer in that region of the world, whereas the southern hemisphere experiences the shortest day of winter. The solstice occurs on or around June 20th. Another solstice occurs six months later, when the tilt is reversed. The south pole is now slanted towards the sun, while the north pole is angled out into space. This is the shortest day in the north and the longest day in the south, occurring around December 21. Winter is the finest time to go stargazing. This is when your pole points away from the Sun, resulting in shorter days and longer nights.

PLANET ATMOSPHERE

Earth’s atmosphere is a delicate and dynamic layer that envelops the planet, allowing life to exist while also sheltering it from the harsh conditions of space. The Earth’s atmosphere is unique in the solar system because it can support life. It is made up mostly of nitrogen (78%) and oxygen (21%), with trace amounts of argon, carbon dioxide, water vapour, and other gases. Most living species require oxygen to breathe, whereas carbon dioxide is essential for photosynthesis, the process by which plants generate energy and oxygen.

The atmosphere is divided into layers, each with its own specific properties. The troposphere, the lowest layer, stretches to about 12 kilometres (7.5 miles) and is home to the majority of Earth’s meteorological phenomena, such as clouds, rain, and storms. Temperature in this layer tends to decrease with altitude. The stratosphere is located above the troposphere and reaches a height of roughly 50 kilometres (31 miles). The stratosphere contains the ozone layer, which absorbs and scatters ultraviolet solar energy, shielding living beings from damaging UV rays.

Beyond the stratosphere comes the mesosphere, where temperatures drop dramatically, making it the coldest layer. Above it is the thermosphere, where temperatures rise dramatically due to the absorption of high-energy X-rays and UV light. The thermosphere is also where the auroras, or northern and southern lights, occur, which are caused by charged particles from the Sun interacting with the Earth’s magnetic field. The exosphere is the outermost layer, which fades into space.

The greenhouse effect, in which gases such as carbon dioxide and water vapour trap heat from the Sun, helps to regulate the planet’s temperature and maintain a climate suitable for different ecosystems. Human actions, such as the use of fossil fuels, have increased the concentration of greenhouse gases, contributing to global warming and climate change. The atmosphere also protects Earth from meteoroids, which burn up upon impact due to friction with air particles, and serves as a medium for the transmission of sound and light. This complex and life-sustaining atmosphere contributes to Earth’s status as the only planet known to support life.

HUMAN CIVILIZATION

Humans began to migrate 350,000 years ago from their original primates in East Africa, and with the advent of agriculture in the 10th century BC they became increasingly dominant on Earth’s land. The first societies emerged between 4000 and 3000 B.C.E., a period marked by the advent of farming and commerce, which enabled individuals to produce more food and achieve economic steadiness. This shift freed many from the necessity of agricultural labour, paving the way for a wide variety of careers and hobbies to thrive within a limited space. The first societies were found in Mesopotamia (present-day Iraq) and Egypt, followed by the Indus Valley around 2500 B.C.E., China by 1500 B.C.E., and Central America (present-day Mexico) by 1200 B.C.E. Societies eventually spread across every continent, except for Antarctica.

Mining (extracting resources) from the Earth's upper crust
Transportation is the major reason of pollution

CONSERVATION & SUSTAINABILITY

  • Conservation of natural resources: The natural resources of earth include air, water, soil, minerals, fuels, plants, and animals. Out of all these we need food, water, air and shelter to survive. All of these are renewable resources. But on the other hand, fossil fuels cannot be replaced at all. Once they are used, they cannot be regenerated. These are non-renewable resources. Over the last 200 years, there has been a significant increase in the human population. As Williams of people consume food, construct homes, manufacturing good, burn fossil fuels for energy and transportation, resources are depleted rapidly. The cautious application of natural resources is essential to the continuance of life as we know it.
  • Sustainable Practices: The wise management of natural resources for the good of the human race as a whole is known as sustainable utilisation of natural resources. Supplying resources for current generations without sacrificing the requirements of future generations is the primary goal of the sustainable development.
  • Global initiatives: Global initiatives such as the Paris Agreement and the United Nations Sustainable Development Goals aim to conserve natural resources, combat climate change, and promote sustainability through international cooperation, renewable energy adoption, and biodiversity protection to ensure a healthier planet for future generations.

FUTURE OF EARTH

  • Technology Advancement: Technology is essential to environmental conservation because it offers creative ways to stop and even reverse environmental damage. It makes data driven decision making and well, informed conservation plans possible by facilitating the monitoring and evaluation of ecosystems.
  • Population Growth: As of 2024, the global population is nearing about 8 billion people, which will reach 10 billion people in 2050. This 8 billion people consumes too much resource. Our Earth generated some of its own resources. But our consumption is much more than what Earth generated on its own. As a result, in the future, these fossil fuels will slowly run out. So, we need to depend on other energies like wind energy, geothermal energy, solar energy, and hydroelectric energy.
  • Earth Long Term Survival: The long-term sustainability of the Earth relies on striking a balance between technological advancement and environmental conservation. Climate change, resource depletion, and biodiversity loss all pose threats to the planet’s future. However, sustainable habits, global cooperation, and innovation have the potential to offset these threats, guaranteeing that the Earth can support life for generations to come. Proactive action is critical.

CONCLUSION

Earth, the third planet from the Sun, is ideally suited to host life due to its ideal balance of atmosphere, water, and temperature. Its various environments, which range from oceans to mountains, support a large variety of biological types. The Earth’s atmosphere guards it from dangerous solar radiation, while its magnetic field protects it from cosmic forces. Plate tectonics and volcanic eruptions continuously modify the planet’s surface. As humanity’s home, Earth supports over 8 billion people and numerous species, making it the most valuable and researched planet, emphasising the necessity of protecting its fragile ecology for future generations.