OUR UNIVERSE

OUR SOLAR SYSTEM

• a collection of small and large bodies that orbit the sun
• Consists of nine different planets
• A planet is a spherical body that orbits the sun
• Closest planets to sun are terrestrial planets
• Earth, Mars, Venus, and Mercury

COMPOSITION OF TERRESTRIAL PLANETS

• Small
• Dense
• Rocky

GAS GIANT PLANETS

• Far away from the sun
• Consists of Saturn, Jupiter, Neptune, and Uranus
• Have small Rocky cores
• Thick gassy atmospheres
• Have rings made of dust, ice, and rock

DWARF PLANETS

• Pluto is a dwarf planet (it is still in our solar system)
• Dwarf planets are made out of rock and ice
• There are five other Dwarf planets

THE UNIVERSE

• Contains everything
• is defined as space, matter and all energy in it
• Has many stars
• A light year is the distance that light travels in a year

SCALE DISTANCES OF THE UNIVERSE

• Light travels through space at about 9.5 trillion km in 1 year
• closest star to the Earth and sun is Proxima Centauri
• Distance from Proxima Centauri to Earth is about 4.3 light-years

TIME OF SPACECRAFT TRAVEL

• Our fastest spacecraft would take 75,000 years to reach Proxima Centauri

LIFE CYCLE OF HIGH MASS STARS

• Hydrogen cycle ends
• Other types of fusion begin
• Involves fusion of nuclei in elements heavier than carbon
• Star expands and becomes supergiant

CAUSE OF SUPERNOVA

• A supernova is a gigantic explosion when a high mass star throws its outer layers

DEATH OF A HIGH MASS STAR

• Core of star contracts under its own gravity
• Contraction leads to increase in core's temerature
• Energy is transferred to thin shell of surrounding hydrogen
• Fusion radiates energy outward causing star to grow larger
• Star begins ejecting matter, rapidly lose mass until core remains, the rest depends on star's mass

HOW TO USE HERTZSPRUNG-RUSSELL DIAGRAM

• Hottest stars will be located on the left side of the diagram and are blue
• Coolest stars will be located on the right side of the diagram and are red
• Brightest stars on the top, dimmest stars on the bottom

THE MAIN SEQUENCE (H-R DIAGRAM)

• Region of the diagram where stars spend most of their lives
• Stars within this band are fusing hydrogen activley
• These stars are called main sequence stars
• Our sun is a main sequence star
• Fusion ends, sun becomes a giant, moves to upper right, outer layers are lost, sun becomes white dwarf

THE END