Solar Nebula Theory 4:30

The rotation accelerates as our solar system condenses 2:09

Where Did The Solar System Come From? The present theory of the formation of the solar system is called the Solar Nebula theory. A scientific theory is an explanation that fits all the evidence. This theory is consistent with what we know of our solar system and what we know of the rest of the galaxy.

What Evidence is There for Solar Nebula Theory? We can see other solar nebulas forming stars. Almost all space rocks have been radioactively dated to 4.6 billion years. All planets revolve around the sun in the same counter clockwise rotation most also revolve in the same direction these seem to indicate a common origin. Moon rocks are 3.8 billion years old. Computer simulations – given a cloud collapsing under gravity, systems like our solar system form. The moon is pockmarked with large craters some formed by impact objects hundreds of miles in diameter. Most of these craters are about 3.8 billion years old, indicating that impacts were much more common in the past.

How did the Solar System form? A large cloud of gas and dust started to collapse and spin together under the force of gravity. 2. Most material settled in the center forming a protosun, which grew hotter and hotter. 3. Denser elements mostly metals began to condense in stops near the sun. Hydrogen (H) and Helium (He) are driven off by the sun’s heat. In the outer solar system the less dense elements began to condense. 4. Gravity continued to pull clumps of material together as it rotated around the protosun, eventually forming protoplanets. 5. Collisions continued for hundreds of millions of years increasing the size of the planets.

Birth of a Solar System Once most of the collisions were over, we were left with a solar system consisting of 8 planets and countless smaller objects known as satellites, asteroids, meteoroids, and comets. The protosun eventually grows so large and hot that nuclear fusion occurs in its center, and a star is born. Hydrogen + Hydrogen ------ Helium + Energy What is unusual about this reaction is that the mass of the produced is less than the mass of the two hydrogen atoms!! What is unusual about this reaction is that the mass of the produced is less than the mass of the two hydrogen atoms!!

Nuclear Fusion Hydrogen + Hydrogen ------ Helium + Energy What is unusual about this reaction is that the mass of the produced is less than the mass of the two hydrogen atoms!! Where does the lost mass go? It turns into energy! E=mc2 which is the research that Einstein did in 1906, which later earned him a nobel Prize. E = Energy M= lost mass C=speed of light A tiny amount of “lost” mass becomes a huge amount of energy. One pound of mass being turned into energy could power all the energy demands of NH for 170 years!

More Amazing Facts Every second 600,000,000 tons of Hydrogen is turned into Helium in the sun’s core! Every second 4,200,000 tons of the sun’s mass becomes energy ! This energy is radiated in all directions and is made up of all types of Electromagnetic Waves traveling at the speed of light. We depend on this energy! Life is not possible without it! Don’t worry!! At present rate, the sun will last for another 5 billion years.

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