Space Science – Lesson 1: Components of Space

What are you made of? Space Science – Lesson 1: Components of Space

“The Most Astonishing Fact” Video Space Science – Lesson 1: Components of Space

Our Solar System Solar system: a star and all the objects that travel in orbit around it Our solar system is located in an outward spiral of Milky Way galaxy. From NASA at Lesson 1 – Components of Space

Theories of the solar system There have been historically two models to explain the rotation of celestial objects around Earth: 1. Geocentric Model: Everything (sun & other planets) revolve around Earth Proposed by Pythagoras, an ancient Greek scientist We are the center of the universe Lesson 1 – Components of Space

Theories of the Solar System 2. Heliocentric Model: The Earth and planets revolve around the Sun - Heliocentric model (helio = Sun) - Proposed by ancient Greek, Aristarchus - Was rejected until the 1600’s But was supported by Polish astronomer Nicolas Copernicus and Galileo (1564–1642) supporter of Copernicus’s ideas In 1609, Galileo he used a telescope for the first time to view Moon and planets; observations exposed errors in the geocentric model

Despite the amount of evidence to support the heliocentric model, there are still people who reject his model. i Theories of the Solar System

What are some components of the Solar System? Space Science – Lesson 1: Components of Space Other space objects Planets Stars Comets Moons Asteroids Satellites Dwarf Planets

Space Science – Lesson 1: Components of Space

Components of Our Solar System Lesson 1 – Components of Space Key Terms: 1.Planet – object orbiting a star or stellar remnant that is big enough to be rounded by its own gravity 2. Dwarf Planet – much smaller than a planet (smaller even than Earth's moon) -Orbit the Sun just like the eight major planets -Not able to clear their orbital -E.g. Pluto

Key Terms: 3.Moon (natural satellite) – celestial body that orbits another body (e.g. a planet) 4.Star – huge ball of gas held together by gravity -Central core is extremely hot and produces energy -Some energy released as visible light 5.Meteroroids – Little chunks of rock and debris in space are called meteoroids -They become a meteor (shooting stars) when they fall through a planet's atmosphere -When they land on the ground they are called meteorites Lesson 1 – Components of Space

Key Terms: 5.Comet – snowballs of frozen gases, rock and dust -~ size of a small town -Dust & gases form tail that stretches away from Sun for millions of km -Has a very elliptical orbit 6.Asteroid – Rocky, airless objects that orbit the Sun -Too small to be dwarf planets & planets -Tens of thousands gathered in the main asteroid belt b/w the Mars & Jupiter -Asteroids that pass close to Earth called near-earth objects. 7.Satellite – artificial object that has been intentionally placed into orbit (different from natural such as the moon) Lesson 1 – Components of Space

“Our Solar System” Video Space Science – Lesson 1: Components of Space

Ancient astronomers saw points of light that appeared to move among the stars - They called these ‘planets’, meaning ‘wanderers’ - Named them after Roman gods Can you name the 8 planets? Hint: One is named after him  Planets The Solar System - Planets

Term ‘solar system’ derived from “sol” meaning the Sun 8 Planets (in order starting from closest to the Sun): 1. Mercury 2. Venus 3. Earth 4. Mars 5. Jupiter 6. Saturn 7. Uranus 8. Neptune *Pluto no longer considered a planet  known as dwarf planet planet Planets Mnemonic device: My Very Elegant Mother Just Served Us Nine Pizzas

4 innermost planets called terrestrial planets (meaning “Earth-like”) - Almost circular orbits around Sun - Mercury, Venus, Earth, & Mars The larger outer planets called gas giants - Outer layers are composed of gases such as hydrogen and helium - Move in elliptical or oval orbits - Jupiter, Saturn, Uranus, & Neptune The Planets

The terrestrial planets The Planets

The gas giants The Planets

The Planets

The planets to scale. The rings of the gas giants are not shown. The Planets

(Distance between objects not to scale) The Planets

Earth How small are we? source: Celestia (application) (Distance between objects not to scale) The Planets

Earth’s Movement In Space Babylonians, Mayans, indigenous Australians used the movements of the Sun and Moon to define their days, months, seasons, and years - Developed complex ways to predict seasonal changes - Allowed ancient people to plan when to plant crops - Survival depended on this knowledge of the Earth’s movement in space Earth’s Movement In Space

Planets rotate on their axes as they orbit Sun Rotation: time taken for a planet to spin once on its axis - 1 rotation = 1 day Revolution: time taken to orbit the Sun once - 1 revolution = 1 year ( days) The earth spins on its axis, causing alternating day and night Earth’s Movement In Space Can you predict a planet that would have long “Earth-years”? Which planets would have short days?

The Earth spins once on its axis in a day, and takes a year to orbit the Sun. Earth’s Movement In Space

As the Earth orbits the Sun, tilt causes different parts of the Earth to experience different heating effects Summer solstice  days are longest Winter solstice  days are shortest At the two equinoxes, length of day = length of night Science Focus 1: Coursebook Earth’s Movement In Space