Knowledge Point 01: The Nearest Star to Earth is the Sun
The nearest star to Earth is the Sun, which is located at the center of the solar system and provides light and heat to Earth. As a G-type main-sequence star, the Sun generates energy through nuclear fusion reactions, radiating this energy into space in the form of light and heat, benefiting the planets of the solar system, including Earth.
The existence of the Sun not only maintains life activities on Earth but also drives the Earth’s climate system and various natural phenomena.
Knowledge Point 02: Earth is the Third Planet Closest to the Sun in the Solar System
Earth is the third planet closest to the Sun in the solar system, with a shape of a slightly flattened triaxial ellipsoid at the poles and bulging slightly at the equator. Earth’s surface is covered by an atmosphere that protects it from harmful radiation and tiny particles in space.
The Earth’s surface is mainly composed of land and oceans, nurturing a diverse range of life forms, including humans, animals, plants, and microorganisms. These life forms interdepend through complex ecosystems, collectively constituting the unique biodiversity on Earth.
Knowledge Point 03: Earth’s Shape and Atmospheric Protection
Earth’s shape is a slightly flattened ellipsoid, caused by the centrifugal force generated by its rotation.
The atmosphere surrounding Earth is crucial for the planet, as it not only provides a protective layer that prevents harmful radiation and tiny particles in space from directly impacting Earth’s surface but also maintains life activities on Earth by regulating the climate and protecting organisms from ultraviolet radiation damage.
Gases such as water vapor and carbon dioxide in the atmosphere also participate in Earth’s greenhouse effect, keeping the planet within a suitable temperature range.
Knowledge Point 04: The Evolution of Human Understanding of Earth
Human understanding of Earth has undergone a long and complex evolutionary process. In ancient times, people believed that Earth was the center of the universe and that gods created humans and all things. With the development of science, people gradually recognized that Earth is just a planet in the solar system, and the solar system is a tiny component of the Milky Way.
Advances in modern astronomy and geology have enabled us to gain a deeper understanding of Earth’s origin, structure, and evolutionary process, as well as its position and role in the universe. These insights have not only enriched our scientific knowledge but also promoted the progress and development of human civilization.
