SPACE : The big bang

 The Big Bang:

    It is by studying space that we understand how our planet was formed. The wild forces that have shaped our Earth for billions of years are still exercising their power. The extreme heat that reigns below the surface of the Earth transforms into fusion the rocks that are then spat out by the volcanoes. Huge sections of the Earth’s crust move, causing earthquakes. Extreme high temperatures in the center of the Earth are caused by natural radioactivity and chemical reactions. The sun, however, is much warmer, and without its light and heat, life on Earth would not exist. But in reality, the history of Earth begins with the big bang! , the inconceivable explosion that created the Universe.

Something from nothing!

     Scientists today agree that it all started with the big bang: space, time and matter in the Universe. About 15 billion years ago, an explosion of unbelievable power brought the Universe to life. This initial ball of energy was so focused that it gave birth to matter. At the time of its creation, the Universe was infinitely hot and dense. It then expanded, cooled, and galaxies, stars, and planets formed. Thus was born our solar system, about 4.6 billion years ago.

The creation of stars:

    At the heart of its cloudy cluster of cosmic dust, the spectacular Orion nebula gives birth to stars. This is how our sun system was created billions of years ago.
   The primitive solar nebula, rotating on itself, has accumulated in its center more and more dense matter. By compressing, they heated up. And when the temperature reached several million degrees, nuclear fusion reactions began.
   This is how the sun was born, at the heart of our solar system.

The solar system:

    At its birth, the sun was probably in the center of a circular mass of matter formed mainly of dust, liquid, ice and gas.
   Under the action of the forces of gravity, the dust particles have gathered into rock masses. The matter made up of minerals, close to the sun, has agglomerated to form the inner planets, at its solid surface. The outer planets, farther from the sun, are gaseous, made up of rocks and light gases or ice.

Unique planet!

    Of all the planets in the solar system, the Earth, our planet, is unique. Its gravity field allows it to have a protective atmosphere, dotted with clouds. The water of the blue oceans covers it by three quarters and it is located just at the right distance from the sun to have neither warm nor too cold climates. Water and the atmosphere are the two essential conditions for life as we know it to exist.

Are we alone in the univers?

    It is unlikely that the conditions that have allowed life on Earth to hatch in such complex forms will exist elsewhere in the Universe. However, simple microbes can survive in hostile environments and may exist on other planets or their moons. In 1996, a Martian meteorite discovered in Antarctica contained what appeared to be a fossilized bacterium (left). So, some scientists believe that a simple microbial life form could have existed on Mars.