Minerals.

Minerals, also known as mineral species are parts of rocks and chemical elements.

There are many different minerals. Calcium (Ca), phosphorus (P), and iodine are minerals, too.

These elements are found in the bowels of the Earth.

Minerals are used in various fields.

Source of image:

https://www.shutterstock.com/image-photo/pyrite-mineral-crystalpyrite-crystal-396999130

Soil.

Soil or earth is a mixture. In it there are many different minerals. Also, there are different types of soil.

In order for plants to grow on the ground, it needs to be looked after.

Animals can live in the soil.

Source of image:

https://www.shutterstock.com/image-generated/tomato-plant-planted-cross-section-soil-2478482439

Sky of our planet.

The sky is the space above the surface of the Earth. The sky is blue; there are also clouds, rain, snow, rainbow in it.

During sunset the sky becomes horizontal pink and later dark. Also, there are the stars and/or the Moon.

The sky is blue color during the day.

Source of image:

https://www.shutterstock.com/image-photo/real-amazing-panoramic-sunrise-sunset-sky-1917169625

Tundra.

Tundra is a biome with a cold climate. It's situated in the Northern Hemisphere.

In tundra there are many different plants and animals. Its adapted to the local weather.

Tundra is located near the Arctic.

Source of image:

https://www.shutterstock.com/image-vector/biomes-terrestrial-ecosystem-community-living-organisms-2095130674

Source of image:

https://www.shutterstock.com/image-vector/tundra-biome-isometric-3d-style-terrestrial-1370079827

Source of image:

https://www.shutterstock.com/image-vector/tundra-graphic-black-white-landscape-sketch-1589595670

Aurora.

Aurora or the polar light is a light in the sky. This phenomenon occurs during the cold season.

During the aurora borealis, the magnetosphere and the solar wind interact in the Earth's atmosphere.

The polar light appears in the dark sky. The color of the aurora is bright.

Source of image:

https://www.shutterstock.com/image-photo/multicolored-northern-lights-aurora-borealis-on-583808584

Source of image:

https://www.shutterstock.com/image-photo/colorful-northern-light-iceland-658551715

Source of image:

https://www.shutterstock.com/image-illustration/aurora-borealis-abstract-background-northern-lights-1204628455

Gaia.

Gaia (Γαῖα) (Γῆ) was known as a goddess of the Earth in Greek mythology. Her parents were Chaos (χάος) and Nyx (Νύξ). 

Uranus was Gaia's husband. They had many different offspring. Among them were: the Titans, the Cyclopes (Κύκλωπες), the Gigantes (Γίγαντες), and etc. 

The goddess of the Earth, Gaia, met with other characters from legends. 

Paleontology.

Paleontology (παλαιοντολογία) is the study about life on the Earth, which existed before Holocene epoch. This word came from the Greek language παλαιός, palaios  "old", ὄν, on "creature", and λόγος, logos "study".

Science about ancient creatures has similar features with other studies. Biology, geology, and archaeology are related sciences to paleontology. 

Paleontologists are studying the history of life on our planet. Ancient fossils can tell a lot about animals and their lives.

Also, scientists study climate of that periods. Billions and millions years ago the weather was different. Ice age changed life of animals.

Paleontology helps to understand the life of dinosaurs. They lived on the Earth many years ago. Then the dinosaurs died.

This science explains evolution. Different animals have different ancestors. They could be of other size and live in other places.

Plants at that time were different, too.

Science about ancient animals studies in colleges and universities.

Source of image:

https://www.shutterstock.com/es/image-vector/cartoon-paleontology-kids-working-on-excavation-1433866022

Source of image:

https://www.shutterstock.com/es/image-vector/archaeologist-near-archaeology-items-dig-equipment-1513927937

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https://www.shutterstock.com/es/image-vector/archaeologists-paleontology-scientists-working-on-excavations-1307853316

Source of image:

https://www.shutterstock.com/es/image-vector/cute-man-archaeologists-cartoon-searching-fossil-601596866

Source of image:

https://www.shutterstock.com/es/image-photo/background-ammonite-shells-concretions-other-paleontological-1835368402

Ice age.

 Ice age is a period in history of Earth. In that time climate changed on our planet. The temperature became lower in different places.

There were many ice ages: the Huronian (2.4-2.1 billion years ago), Cryogenian (850-635 million years ago), Andean-Saharan (460-430 million years ago), Karoo (360-260 million years ago), and Quaternary (2.6 million years ago-present).

During these periods landscapes and Earth's surface changed. Ice aged influenced many different things on our planet.

At the end of these events some animals became extinct, such as: saber-toothed cats, the mastodons, giant ground sloth, wooly mammoth, and other.

Homo sapiens appeared. Humans created new tools for survival in a cold climate. Also, ancient people developed agriculture.

Geology is a science of study ice age. Scientists named geologists study these important periods. They found plants and animals in large glaciers.

Source of image:

https://www.shutterstock.com/es/image-vector/collection-ice-age-animals-mountains-280531367

Source of image:

https://www.shutterstock.com/es/image-illustration/illustration-herd-woolly-mammoths-grazing-early-347240843

Source of image:

https://www.shutterstock.com/es/image-illustration/sabertoothed-cat-tries-drive-shortfaced-bear-1157175928

Geography.

Geography (γεωγραφία) is a field of study. It means "earth description" from Greek language. There are two parts of this science: physical geography and human geography.

Physical geography studies about nature and the climate of our planet Earth. Oceans, forests, mountains are different. Somewhere there are volcanoes and hot weather. Somewhere there are plains and fields.

Also, science about Earth explained structure of the planet. Atmosphere, asthenosphere, hydrosphere, crust, rigid mantle, stiffer mantle, outer core, and inner core are parts of Earth.

Human geography is another part of the science about our planet. It studies about people and their countries. Population, economics, culture, politics, languages, territory are show human geography. Name of capitals and other cities of specific country.

Students study different parts of geography during school lessons. Maps and globes help with it. These subjects can be for physical and human geography.

This science is interesting.

Source of image:

https://www.shutterstock.com/es/image-vector/globe-maps-compass-others-school-subjects-775265689

Source of image:

https://www.shutterstock.com/es/image-vector/creative-illustration-geography-line-icon-632205098

Source of image:

https://www.shutterstock.com/es/image-vector/layers-earth-structure-strata-shown-scale-726253207

Christopher Columbus.

(This is essay by my brother).

Christopher Columbus was an Italian explorer famous for discovering America. He was born on October 30, 1450 in Genoa, Republic of Genoa (now part if Italy).

He wanted to sail for India, but not in the direct route. Columbus believed that Earth was round and wanted to get to India from the other side. Portuguese government declined Columbus' request to fund this expedition, but the nation of Crown of Castile granted it.

So, on August 3, 1492, Christopher Columbus departed to India with three ships: Santa Maria, Pinta, and Nina. On October 12, 1492, Columbus landed on what he at first thought was India, that's why the natives are called Indians. But later Columbus realised that he discovered the New World. He returned to Spain on March 15, 1493, and the word about discovery of the New World spread rapidly.

Christopher Columbus went on three more voyages to America, where he found new cities, new people, new goals. But, on his last expedition, his ship wrecked near Jamaica. He was stranded for a year until the rescue and retarned to Spain seriously ill on November 7, 1504. He died from his illness on May 20, 1506, at the age of 54.

Source of image:

http://www.shutterstock.com/pic-110860961/stock-vector-christopher-columbus.html?src=tUIBYA3VFszvVZ3w3bfHmg-1-3

Universe.

When we see starry night sky, we see a little part of large universe with a plurality of different stars including our sun. The Solar System is also a little part of space. Our planet, Earth, the third from Sun. Neighboring planets such as Mars and Venus have similar similar structure with Earth. For example many, many years ago on the planet Mars, there was life! But now just Earth has living conditions.

Scientists studying universe have found stars which are more bigger than our Sun; main star of the Solar System! Some of them twirl around another planets. But human was not on any other planets apart from Motherland-Earth. But may be in the future people can fly on other planets and even systems.

Universe has dark area and stars with planets. Also planets have one or more satellite of Earth is the Moon.

Sometimes we hear news or stories about UFO or Unidentified flying object. May be it has our "brothers" from another systems or universe. But somebody thinks that all of it simple fiction.

Universe is ome of the greatest mysteries in our history.