Because it was a long time ago and later planterary events have hidden or erased most trace of it.
Biosphere.
The study of the Earth's physical structure and history is known as geology. Geologists analyze rocks, minerals, landforms, and layers of the Earth to understand processes like plate tectonics, erosion, and sedimentation that have shaped the planet over millions of years.
The amount of oxygen in Earth's atmosphere has fluctuated over geological time scales. Oxygen levels were much lower in the past, particularly in the early stages of Earth's history. Around 2.4 billion years ago, there was a significant increase in oxygen levels known as the Great Oxidation Event, leading to the current levels of approximately 21% oxygen in the atmosphere.
greenhouse effect
Other than Earth, Mars is also known to have experienced magnetic pole reversals in its history. Evidence from the planet's crust suggests that its magnetic field has reversed multiple times over millions of years, similar to Earth's magnetic field reversals.
Since the Incas never developed a system of writing, we must rely on the writing of their Spanish conquerors.
Since the Incas never developed a system of writing, we must rely on the writing of their Spanish conquerors.
Little is known about her family as she was taken away at an early age. Lewis & Clark never really got much information about her early history so much that happened before she worked with them was not written down.
Very little is known in history about the Etruscans and they were simply known as the mysterious people from the sea.
Found in 1747
One person to have it in early history was Alexander the Great.
That is a statement, not a question.
Very little is known about Botticelli's early life or last years.
Abel Tasman was born around 1603 in the Netherlands. Little is known about his early life and education, but he likely grew up in the town of Lutjegast. Tasman first appears in recorded history as a young man serving in the Dutch navy during the early 17th century.
British King George V controlled the largest empire in history, known as the British Empire, which covered about 23% of the Earth's total land area at its height in the early 20th century.
The Maori and Greek Gods were known to be close. This Gods were well known in the early modern era.
Phony War.