SOLAR SYSTEM

Our cosmic neighborhood

Our Cosmic Neighborhood

From our small world we have gazed upon the cosmic ocean for thousands of years. Ancient astronomers observed points of light that appeared to move among the stars. They called these objects "planets," meaning wanderers, and named them after Roman deities—Jupiter, king of the gods; Mars, the god of war; Mercury, messenger of the gods; Venus, the goddes of love and beauty, and Saturn, father of Jupiter and god of agriculture. The stargazers also observed comets with sparkling tails, and meteors or shooting stars apparently falling from the sky.

The solar system is made up of the Sun, the 8 planets and 5 dwarf planets and their 174 known moons, asteroids, comets, dust and gas. The planets, asteroids, and comets travel around the Sun, the center of our solar system.Most of the bodies in the solar system travel around the Sun along nearly circular paths or orbits, and all the planets travel about the Sun in the anticlockwise direction

The four planets closest to the sun—Mercury, Venus, Earth, and Mars—are called the terrestrial planets because they have solid rocky surfaces. The four large planets beyond the orbit of Mars—Jupiter, Saturn, Uranus, and Neptune—are called gas giants. Tiny, distant, Pluto has a solid but icier surface than the terrestrial planets.

Nearly every planet—and some of the moons—has an atmosphere. Earth's atmosphere is primarily nitrogen and oxygen. Venus has a thick atmosphere of carbon dioxide, with traces of poisonous gases such as sulfur dioxide. Mars's carbon dioxide atmosphere is extremely thin. Jupiter, Saturn, Uranus, and Neptune are primarily hydrogen and helium. When Pluto is near the sun, it has a thin atmosphere, but when Pluto travels to the outer regions of its orbit, the atmosphere freezes and collapses to the planet's surface. In that way, Pluto acts like a comet.

 

How Did The Solar System form?

This is an important question, and one that is difficult for scientists to understand. After all, the creation of our Solar System took place billions of years before there were any people around to witness it. Our own evolution is tied closely to the evolution of the Solar System. Thus, without understanding from where the Solar System came from, it is difficult to comprehend how mankind came to be.

 

Scientists believe that the Solar System evolved from a giant cloud of dust and gas. They believe that this dust and gas began to collapse under the weight of its own gravity. As it did so, the matter contained within this could begin moving in a giant circle, much like the water in a drain moves around the center of the drain in a circle. 

At the center of this spinning cloud, a small star began to form. This star grew larger and larger as it collected more and more of the dust and gas that collapsed into it.

The material spinning around this new star also condensed into several large chunks of material called planetoids. As these planetoids collided, they coallesced into larger bodies to form the planets that exist today. Because the Sun and planets all formed from the same nebular cloud, they all rotate in the same direction that was induced on the disk of material as it coallesced. Not only do the planets all rotate counter-clockwise around the Sun, but the Sun and nearly all the planets rotate counter-clockwise about their axes. The solar equator and the plane containing the orbits of the planets are also nearly identical

Another important difference is that the outer planets are largely made of gas and water, while the inner planets are made up almost entirely of rock and dust. This is also a result of the solar winds. As the outer planets grew larger, their gravity had time to accumulate massive amounts of gas, water, as well as dust.

THE FORMATION OF THE SOLAR SYSTEM

The Universe is about 12 or 13 billion years old, according to current estimates. The Sun, planets, asteroids, and comets that make up our solar system are much younger, relative newcomers at an age of

4.55 billion years (that is, 4550 million years), give or take a mere 50 million

years!

THANK YOU!