THE UNIVERSETHE UNIVERSE

2 THEORIES2 THEORIES

1- GEOCENTRIC THEORY1- GEOCENTRIC THEORY::• Who proposed it?:Who proposed it?:

Ptolomy Ptolomy When?When?

In the 2nd century BCIn the 2nd century BC2- HELIOCENTRIC THEORY2- HELIOCENTRIC THEORYWho proposed it?Who proposed it?

Nicolas CopernicusNicolas CopernicusWhen?When?

In 1542 (16th century)In 1542 (16th century)

What makes up the What makes up the Universe?Universe?

► It is all theIt is all the :: MatterMatter Energy Energy SpaceSpace

►The Universe is made up ofThe Universe is made up of : : GALAXIES.GALAXIES. Galaxies contain STARSGalaxies contain STARS

OUR GALAXY: The Milky OUR GALAXY: The Milky WayWay

PLANETSPLANETS STARSSTARSBodies which orbit Bodies which orbit some starssome stars

Clouds of gases Clouds of gases pulled together by pulled together by gravitational forcesgravitational forces

They don´t emit They don´t emit lightlight

They emit heat and They emit heat and lightlight

OUR SOLAR SYSTEM IS MADE OUR SOLAR SYSTEM IS MADE UP OFUP OF

►ONE STAR: The SunONE STAR: The Sun►8 PLANETS with their Satellites8 PLANETS with their Satellites►Dwarf planets: Pluto, Ceres, ErisDwarf planets: Pluto, Ceres, Eris►Small Solar System bodies:Small Solar System bodies:

AsteroidsAsteroids CometsComets SatellitesSatellites

INNER PLANETSINNER PLANETS OUTER PLANETSOUTER PLANETSClosest to the SunClosest to the Sun Not so close to the Not so close to the

Sun (far)Sun (far)Rocky planets, made Rocky planets, made of rockof rock

Made of gases (Gas Made of gases (Gas giants)giants)

MercuryMercuryVenusVenusEarthEarthMarsMars

JupiterJupiterSaturnSaturnUranusUranusNeptuneNeptune

ASTEROID BELTASTEROID BELT

Units of measurementUnits of measurement►Astronomical unitsAstronomical units

The distance from The distance from the Earth to the Sun.the Earth to the Sun.

Light-yearLight-yearThe distance light travels in one yearThe distance light travels in one year..

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