The Origin and Evolution of the Earth Test - 1

A body of the size of one to three times that of Mars collided with the Earth sometime shortly after the Earth was formed. It blasted a large part of the earth into space. This portion of blasted material then continued to orbit the earth and eventually formed into the present moon about 4.44 billion years ago.

Modern scientists refer to the origin of life as a kind of chemical reaction, which first generated complex organic molecules and assembled them. This assemblage was such that they could duplicate themselves converting inanimate matter into living substance. The record of life that existed on this planet in different periods is found in rocks in the form of fossils. 

Solar winds, Degassing, and the Photosynthetic process is related to the modification of the atmosphere on Earth so that life can originate while, Differentiation or Organization leads to the formation of a core, a crust, and eventually continents.

The solar wind was most intense nearer the sun; so, it blew off lots of gas and dust from the terrestrial planets. The solar winds were not all that intense to cause similar removal of gases from the Jovian planets. The terrestrial planets are smaller and their lower gravity could not hold the escaping gases.

A light year is a measure of distance and not of time. Light travels at a speed of 300,000 km/second.

The expansion of the universe means an increase in space between the galaxies.

The Milky Way is a huge collection of stars, dust and gas. It's called a spiral galaxy because if you could view it from the top or bottom, it would look like a spinning pinwheel. The Sun is located on one of the spiral arms, about 25,000 light-years away from the center of the galaxy.

Eons is said to have the longest duration because it is more than one era or a period or an epoch.

However, around 2,500-3,000 million years before the present, the process of photosynthesis evolved. Life was confined to the oceans for a long time. Oceans began to have the contribution of oxygen through the process of photosynthesis. Eventually, oceans were saturated with oxygen, and 2,000 million years ago, oxygen began to flood the atmosphere.

 The earth’s oceans were formed within 500 million years from the formation of the earth.