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A SOLAR SYSTEM IS BORN. Chapter 16 – 1 part 2. The Birth of a Star. As the planets are forming, gas and dust near the center of the solar nebula grow dense . In the center the hydrogen atoms begin to fuse . Fusion creates energy that pushes outward . The star begins to shine.
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A SOLAR SYSTEM IS BORN Chapter 16 – 1 part 2
The Birth of a Star • As the planets are forming, gas and dustnearthe center of the solar nebula grow dense. • In the center the hydrogen atomsbegin to fuse. • Fusion creates energy that pushes outward. The star begins to shine. • A star is born and a new solar system is formed.
Energy Production in the Sun • The sun has been shining for about 4.6billion years. • Tiny amounts of matter can produce a huge amount of energy.
Nuclear Fusion • Nuclear fusion is the process by which two or more low-mass nuclei fuse to form another nucleus. • When hydrogen nuclei fuse they form helium and ignition begins.
Conditions Required for Fusion • Under normal conditions, hydrogen atoms never get close enough to join. • In center of the sun, the temp. andpressureare very high. • This forces the atoms together, so hydrogen can fuse.
Measuring Interplanetary Distances • One way scientistsmeasure distances in space is by using the astronomical unit. • OneAUis the average distance between the Earth and the sun which is 150,000,000 km.
Another Way • Another way to measure distances is by using the speed of light. • A light-minute is how far light travels in one minute, 18,000,000 km. • Distance in the solar system is also measured in light-hours and light-years.