Solar System

The Solar System: a star and all of the objects that travel around it — planets, moons, asteroids, comets and meteoroids

How did it form?

Sort pictures in order https://www.yout https://www.youtube.com/watch?time_continue=105&v=RT4OO0TFLHw

Actual D F C A E B

Solar System to Scale (for size)

People used to think the solar system was Geocentric (Earth Centered) Early Greeks created this model Problems with it included retrograde motion of planets (a figure 8 path) http://www.lasalle.edu/~smithsc/Astronomy/retrograd.html http://www.youtube.com/watch?v=72FrZz_zJFU

Later observations confirmed the Heliocentric Model (Sun Centered) Described in 1543 by Copernicus Confirmed by Galileo using his telescope to observe Venus

The force of gravity from the sun holds our solar system together. The larger an object’s mass, the greater its gravitational force.

The Sun contains 99.86% of all the Solar System’s mass.

Planets closer to the Sun orbit the Sun FASTER than planets farther from the Sun. http://www.kidsastronomy.com/solar_system.htm

Which planet in each pair takes longer to orbit the Sun? Neptune or Jupiter? Mars or Earth? Venus or Mercury? Uranus or Saturn? Pluto takes 248 years to complete one orbit!

What makes something a planet? Requirements to be qualified as a planet: Must orbit the star (sun) Must be large enough to have its own gravity pull it into a sphere Must have a clear path around the sun (no smaller objects in its way)

The Inner Planets

The Inner Planets Small in size Solid/rocky

Mercury Has no atmosphere due to low gravitational pull (it’s the smallest planet) high daytime temperatures (2nd hottest planet) solar winds blast away any remaining gasses

Venus The solar system’s warmest planet Heat is trapped due to the intense greenhouse effect due to the thick atmosphere. Temperatures average 460 degrees C on Venus

Greenhouse Effect

Image of Maat Mons- the highest volcano on Venus Image of Maat Mons- the highest volcano on Venus. Taken with radar since the temperature and pressure destroy any probes that land on the surface.

Earth Earth is unique because It has lots of liquid water (not just frozen or gas forms) Life is found here.

Mars Features of Mars Ice caps (on N and S poles) Volcanoes (largest in the solar system –taller than 3 Mt Everests and wider than Hawaiian island chain)

No Oceans (may have lots of frozen water or even salt water below the surface) http://www.google.com/mars/ No life (yet…) A thin atmosphere of mostly carbon dioxide Seasons (it has a tilted axis like Earth) 2 moons No hot temperatures (range is -125C to 35C)

The Outer Planets

Outer Planets Large in size Made of gas Have rings Have many moons

Jupiter Jupiter’s atmosphere: Hydrogen and helium If Jupiter were a little larger, it may have turned into a small star

We closely study Jupiter’s moons Studying these moons add to the knowledge about the origin of Earth and the rest of the solar system

Saturn’s rings are made out of particles of … Ice and rocks

Uranus Rotates on its side- A collision with another object probably tipped it over.

Neptune Discovered in 1846 Methane gases give Neptune it’s blue-green color

Dwarf Planets

Dwarf Planets http://www. youtube. com/watch Orbit the sun, but have not “cleared the neighborhood”- no clean path around Sun Be spherical in shape, but small

Identify reasons why Pluto is different from the other outer planets Only has a thin atmosphere, other outer planets have thick atmospheres. Only outer planet with a solid, icy-rock surface

Orbit of Pluto

Planet Names http://planetarynames.wr.usgs.gov/append7.html Scale sizes of solar system: http://en.wikipedia.org/wiki/Solar_System_model http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.html Scroll to the right