a look at our solar system

A look atOur Solar System

It all starts with …..

ARISTOTLE

GEOCENTRIC MODEL – everything revolves

around earth.

Ptolomy –Orbits werePerfect circles.

Nicolaus Copernicus

Heliocentric model – all planets revolve around the sun

He’s back – Issac Newton

Gravitational forces keep planets in an orbit around the sun.

It all started about 4.6 billion years ago….

At least that’s what we think

The Nebular Model

Remember – a nebula is a large cloud of dust and gas in space. It is where stars are born or where they explode at the end of their lives

Nebula begins to collapse

Begins to rotate and flatten

Accreation- collision of particles - occurs in the disk. Planets form.

The TERRESTRIAL PLANETS are the ones closer to the sun. Since they were close to the sun, gas and dust did not join together easily. Intense radiation from the sun exerted pressure on these planets, and cause them to loose their lighter materials.

GAS GIANTS formed farther away from the sun, where gas and dust joined easily. These planets were LARGE enough and COLD enough to hold light nebular gases, such as hydrogen and helium in their atmospheres.

Inner planets in our solar system are called TERRESTRIAL PLANETS

Rocky like earth

Have higher temperatures, because they receive more of the sun’s radiation.

The distance in the solar system is measured in astrological units (au) or the distance from the sun to the earth.

MERCURYThe closest planet to the sun

Temperature extremes. Can go from 670 Kelvin to 103 Kelvin at night

Spin slowly on it’s axis. I day on Mercury equals 176 earth days.

VENUSCovered in thick carbon dioxide clouds.Causes a runaway greenhouse effect. The surface temperature is over 700 Kelvin

Its atmosphere contains large amounts of sulfuric acid.One day equals 117 earth days

EarthTwo things allow life to exist

Hydrosphere – all the water on the earth’s surface

The atmosphere – made of mostly nitrogen, it helps moderate temperature, and protects against uv radiation and space debris

MARSSurface is red from iron oxide

Frozen carbon dioxide polar ice caps

Home to the largest volcano in the solar system

Feature indicate water may have once beenpresent

GAS GIANTSLarger outer planets

Separated from terrestrial planets by an asteroid belt

No solid surface, thick gaseous atmospheres

All have rings and satellites

JUPITERAtmosphere consists of swirling clouds of hydrogen, helium, methane, and ammonia

Largest planet in the solar system

Giant Red Spot is a huge hurricane which measures over 2 earth diameters wide.

SATURNSpectacular system of rings

It radiates 3 times more energy than it receives from the sun, so it may still be forming

URANUS AND NEPTUNESimilar in size to one another.

Blue color is due to methane gas in their atmosphere.

PLUTO1930 – 2011 RIP