* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 20.1 A Solar System is Born
Spitzer Space Telescope wikipedia , lookup
Rare Earth hypothesis wikipedia , lookup
Cygnus (constellation) wikipedia , lookup
Astrobiology wikipedia , lookup
Definition of planet wikipedia , lookup
IAU definition of planet wikipedia , lookup
Aquarius (constellation) wikipedia , lookup
Outer space wikipedia , lookup
Comparative planetary science wikipedia , lookup
Planetary system wikipedia , lookup
Directed panspermia wikipedia , lookup
Late Heavy Bombardment wikipedia , lookup
Advanced Composition Explorer wikipedia , lookup
Extraterrestrial life wikipedia , lookup
Planetary habitability wikipedia , lookup
Crab Nebula wikipedia , lookup
Nebular hypothesis wikipedia , lookup
Solar System wikipedia , lookup
Degenerate matter wikipedia , lookup
Star formation wikipedia , lookup
History of Solar System formation and evolution hypotheses wikipedia , lookup
Timeline of astronomy wikipedia , lookup
Orion Nebula wikipedia , lookup
Formation and evolution of the Solar System wikipedia , lookup
4/9/2014 20.1 A Solar System is Born p614 1. Explain the relationship between gravity and pressure in a nebula. 2. Describe how the solar system formed. • Describe the basic structure and composition of the sun. • Explain how the sun generates energy. • Describe the surface activity of the sun and identify how this activity affects Earth. p614 The Solar Nebula The ingredients for building planets, moons, and stars are found • in the vast regions of space between the stars 1 4/9/2014 p614 The Solar Nebula Nebula – a large cloud of gas and dust in interstellar space • Where stars are born or explode at the end of their lives • Hydrogen, helium, carbon, iron • Two forces that interact with nebulas to create planets and stars – Gravity & Pressure p614 Gravity Pulls Matter Together What holds the matter of nebulas together? • The force of gravity Compared to air, nebulas are less dense than air. 2 4/9/2014 p615 Pressure Pushes Matter Apart “Temperature is a measure of the average kinetic energy or the energy of motion, of the particles in an object.” High temp = high movement = particles crash into each other = pressure Why doesn’t the nebula cloud collapse? The outward pressure balances the inward gravity p615 Pressure Pushes Matter Apart Gravity and Pressure in a Nebula (figure 2) 1. Gravity causes the particles in a nebula to be attracted to each other 2. As particles move closer together, collisions cause pressure to increase and particles are pushed apart. 3. If the inward force of gravity is balanced by outward pressure, the nebula becomes stable. 3 4/9/2014 p615 Upsetting the Balance What can upset the balance between gravity and pressure in a nebula? If two nebulas collide or a nearby star explodes What are globules? Small regions or gas clouds of a nebula that are pushed together. p615 Upsetting the Balance “As the matter in a globule collapses… inward the temperature… increases and the stage is set for stars to form.” Solar nebula – the cloud of gas and dust that formed our solar system. 4 4/9/2014 p616 How the Solar System Formed 1. The young solar nebula begins to collapse 2. The solar nebula rotates, flattens, and becomes warmer near its center 3. Planetesimals begin to form within the swirling disk. 4. As the largest planetesimals grown in size, their gravity attracts more gas and dust. 5. Smaller planetesimals collide with the larger ones, and planets begin to grow 6. A star is born, and the remaining gas and dust are blown out of the new solar system. How long did it take our solar system to form? 10 million years p616 From Planetesimals to Planets Planetesimals – small planets • Bits of dust stuck together • Future collisions cause them to grow 5 4/9/2014 p617 Gas Giant or Rocky planet? What are the outer planets of the solar system made of? Nebula gases Name the outer planets made of this matter. Jupiter, Saturn, Uranus, Neptune p617 Gas Giant or Rocky planet? What are the inner planets of the solar system made of? Rocky material Name the inner planets made of this matter. Mercury, Venus, Earth, Mars 6 4/9/2014 p617 Birth of a Star How is a star created? • Matter traveling towards the center becomes so dense and hot that hydrogen atoms began to fuse, or join, to form helium • Fusion releases energy • Outward and inward pressure is balanced • Gas stops collapsing 7