The Solar System

Spectra of ScienceAmole

2013

Early Thought and Models

• Aristotle (384 BC -322 BC)- explained the phases of the moon and eclipses by using a geocentric model

• Ptolemy (90 A.D -168 A.D.)- suggests planets, sun, and moon orbited Earth in perfect circles

Early Thought and Models

• Nicolaus Copernicus (1473-1543)- proposed the heliocentric model

• Johannes Kepler (1571-1630)- propsed that the orbits around the sun were ellipses

What is an Ellipse?• An oval or egg-like shape created from the result of

two foci

Early Thought and Models

• In 1687, Isaac Newton put it all together explaining that the force responsible for keeping the planets and satellites (moons) in their orbits was…GRAVITY

• First to propose that everything in the universe follows the same rules and acts in predictable ways

Bodies in our Solar System:The Sun

• At the center • It’s a medium sized

star in the middle of its life cycle

• Constantly creating energy from nuclear fusion

Bodies in our Solar System:Planets

• Terrestrial Planets:– Small– Dense– Solid surfaces and cores

• Gas Giants (Jovian):– Large– No solid surface– Very light

http://www.google.com/url?sa=i&rct=j&q=dwarf+planets&source=images&cd=&cad=rja&docid=2j3LHGxfccQNuM&tbnid=deFtvkRm1sCL-M:&ved=0CAUQjRw&url=http://www.met.reading.ac.uk/~emily/space/planets/dwarf/pluto.html&ei=1piJUdbxNoa6yQHZ94FY&bvm=bv.46226182,d.aWc&psig=AFQjCNGSYfcTaMwycNC_XdttwF4Gl5ZpcQ&ust=1368058444830130

OMG!• Saturn is the least dense of the planets. It is

actually less dense than water. That means, if you could find a tub big enough….it would float!

OMG!

• We really are so small!

• http://ls.xenia.k12.oh.us/SafeVideos/Video.aspx?id=z6yHKE9dg0g

Bodies in our Solar System:Comets

• Composed of dust and ice (dirty snowballs)

• When it passes near the sun, the heat begins to melt the ice and it gives off gases forming the long tail

• Tail always point away from the sun

Bodies in our Solar System:Comets

• Most likely left-over material from when the solar systems formed

• Come from the Oort Cloud and Kuiper belt

OMG!• Halley’s comet is perhaps the most popular comet. It

passes by every 76 years. Its last pass occurred in 1986, so expect to see it again in 2061!

• Miss Amole will be 76 next time it is here!

Bodies in our Solar System:Asteroids

• Most found in the Asteroid belt between Mars and Jupiter

• Meteoroids small pieces that reach our atmosphere• Meteors-meteoroids that burn up in atmosphere• Meteorites- make it to Earth

OMG!

• Many scientists believe that it was a 10-15 km asteroid or comet that hit the Earth 65 million years ago that is responsible for the extinction of the dinosaurs

OMG!• The best preserved meteorite crater is located in

Arizona. It is over a mile wide, 2.4 miles in circumference, and over 550 feet deep!

Bodies in our Solar System:

Planetesimals• Pieces of rocks that accumulated to form planets• Left over planetesimals are in the Kuiper belt

beyond the orbit of Neptune• Pluto may actually just be the largest object in this

belt

Bodies in our Solar System:

Dwarf Planets• Unlike planets, dwarf planets lack the gravitational

muscle to sweep up or scatter objects near their orbits• They orbit the sun in zones of similar objects such as

the asteroid and Kuiper belts.• Pluto, Eris and the asteroid Ceres became the first

OMG!• Pluto was still a planet

when Miss Amole sat in your seat.

• Pluto was added as a planet in 1930

• In 2005 Eris, about the same size as Pluto, was found in the Kuiper belt

• In 2006 the new system of classification…

http://www.google.com/url?sa=i&rct=j&q=dwarf+planets&source=images&cd=&cad=rja&docid=2j3LHGxfccQNuM&tbnid=deFtvkRm1sCL-M:&ved=0CAUQjRw&url=http://www.met.reading.ac.uk/~emily/space/planets/dwarf/pluto.html&ei=1piJUdbxNoa6yQHZ94FY&bvm=bv.46226182,d.aWc&psig=AFQjCNGSYfcTaMwycNC_XdttwF4Gl5ZpcQ&ust=1368058444830130

How it all Began…

The Formation of the Solar System

Nebular Theory

• According to the dating of rocks, the solar system is 4.6 billion years old

• Most scientist accept the Nebular Theory, or Nebular Model, as the best supported explanation

• It explains why…– Planets are so far apart– In the same plane– orbit in the same direction– They have nearly circular orbits– Why some are terrestrial and some gaseous

Nebular Theory: Step 1

• Started as a nebula- huge cloud or gas and dust• It begins to collapse because of its own gravity• Gravity drew much of the matter towards the

center

Nebular Theory: Step 2

• The nebula began to flatten out into a disk and rotate

• Getting hotter and hotter towards the center• After 10 million years, the star becomes hot enough

to fuse Hydrogen• A star, our sun, is born

Nebular Theory: Step 3

• Planetesimals began to form in the swirling disk through accretion

• Accretion = accumulation of matter

Nebular Theory: Step 4

• The largest planetesimals began to collect the dust and gas from the nebula because they had greater gravitational pulls

• Remember that gravity depends on mass and distance

Nebular Theory: Step 5

• Smaller planetesimals collide with the large ones and the planets grow

Nebular Theory: Step 6

• The remaining dust and gas is removed or settles into the Asteroid and Kuiper belts and Oort Cloud

• A solar system is born

What about the Moon?

The Formation of the Moon

Impact

• When Earth was still very hot and molten, a large body crashed into it and blasted part of the mantle into space

Ejection

• The resulting debris began to orbit Earth being held by Earth’s gravity

Formation

• The debris began to accumulate to form the moon

OMG!

• Formation of Earth and Moon– http://www.youtube.com/watch?feature=fvwp&v

=M4pt0fFn_a4&NR=1• Formation of Solar System– http://www.youtube.com/watch?v=Uhy1fucSRQI

• Formation of Solar System (dramatic)– http://www.youtube.com/watch?v=Tz8ithgTBj4