Class 2:Class 2:

A Trip through the A Trip through the Solar SystemSolar System

• One Star – The SunOne Star – The Sun• 8 Major Planets8 Major Planets• 5 dwarf planets5 dwarf planets• 70 + moons70 + moons

• Unknown number Unknown number of cometsof comets

• Unknown number Unknown number of asteroids.of asteroids.

• We will be traveling outward We will be traveling outward from the center of the solar from the center of the solar system (the sun) to edges of system (the sun) to edges of the system.the system.

• Our voyage will take us 40 Our voyage will take us 40 astronomical units (AU) from astronomical units (AU) from the sun. An AU is the distance the sun. An AU is the distance from the sun to the Earth. from the sun to the Earth. About 93 million miles.About 93 million miles.

• A medium sized star.A medium sized star.• The largest object in The largest object in

the solar system.the solar system.• 99.8% of the material 99.8% of the material

in the solar system is in the solar system is in the sun.in the sun.

• 70% of the sun is 70% of the sun is hydrogen gas. 28% hydrogen gas. 28% helium gas. 2% helium gas. 2% metals.metals.

• The more massive The more massive the object the the object the more gravity it more gravity it has. The sun’s has. The sun’s massive size keeps massive size keeps the planets from the planets from flying away.flying away.

• The sun “burns” The sun “burns” providing most of providing most of the heat and light the heat and light in the solar in the solar system.system.

• Under the intense Under the intense pressure at the heart pressure at the heart of the sun the nuclei of the sun the nuclei of the hydrogen of the hydrogen atoms “fuse” atoms “fuse” together to make together to make helium and release helium and release energy in the form of energy in the form of heat and light.heat and light.

• This process is called This process is called “Nuclear Fusion”“Nuclear Fusion”

• The surface is The surface is 10,000 degrees 10,000 degrees Fahrenheit. Fahrenheit. (Steel (Steel melts at 2,500 degrees melts at 2,500 degrees and Iron boils at 5,000).and Iron boils at 5,000).

• The sun’s The sun’s coronacorona, , extends millions of extends millions of miles into space. miles into space. Temperatures in the Temperatures in the corona are over corona are over 1,800,000 degrees 1,800,000 degrees FahrenheitFahrenheit

• The sun The sun is is 863,705 863,705 miles in miles in diametediameter r (108 (108 times the times the diameter diameter of Earth)of Earth)

• 163,000 miles = 1 foot.163,000 miles = 1 foot.

• In addition to heat In addition to heat and light, the Sun and light, the Sun also emits stream of also emits stream of charged particles charged particles known as the known as the solar solar wind.wind.

• A solar flare can A solar flare can greatly increase the greatly increase the energy of the energy of the particles and cause particles and cause power line surges power line surges and radio and radio interference.interference.

• The solar wind is The solar wind is also responsible for also responsible for the the aurora borealis.aurora borealis.

• 11stst planet out from the planet out from the sun sun (1/3 of an AU).(1/3 of an AU).

• 3,032 miles in diameter 3,032 miles in diameter (less than half the diameter of (less than half the diameter of Earth).Earth).

• Surface temperature Surface temperature ranges from -298 to ranges from -298 to 800 degrees 800 degrees Fahrenheit.Fahrenheit.

• Almost no atmosphere.Almost no atmosphere.• No life.No life.

Mercury’s OrbitMercury’s Orbit• Mercury has no moons.Mercury has no moons.• It orbits the sun once It orbits the sun once

every three months.every three months.• Mercury turns on its axis Mercury turns on its axis

about every four and ½ about every four and ½ months (longer than it months (longer than it takes to do an orbit.takes to do an orbit.

• Because of this a Because of this a Mercury day (From on Mercury day (From on sunrise to the next) sunrise to the next) lasts 6 months.lasts 6 months.

• 22ndnd planet out from Sun planet out from Sun (3/4 of an AU).(3/4 of an AU).

• 7,520 miles in diameter. 7,520 miles in diameter. (About the same as Earth)(About the same as Earth)

• Considered to be Earth’s Considered to be Earth’s “twin.”“twin.”

• Year is 224 Earth days.Year is 224 Earth days.• Rotates Rotates backwards slowly. backwards slowly.

243 earth days equals 243 earth days equals one day on Venus.one day on Venus.

• It was once though that It was once though that beneath the planet’s beneath the planet’s dense clouds there might dense clouds there might be life. Now we know it is be life. Now we know it is too hot.too hot.

• Surface temperature as Surface temperature as high as 872 degrees high as 872 degrees Fahrenheit (hot enough Fahrenheit (hot enough to melt lead)to melt lead)

• Venus has a thick Venus has a thick atmosphere of mostly atmosphere of mostly carbon dioxide. This is carbon dioxide. This is a “greenhouse” gas and a “greenhouse” gas and retains heat. This retains heat. This makes it even hotter makes it even hotter than Mercury.than Mercury.

• The atmosphere is very The atmosphere is very thick.thick.

• 3rd planet from sun 3rd planet from sun (1 AU).(1 AU).

• 7926 miles in 7926 miles in diameter.diameter.

• Surface temperature Surface temperature -130 to + 105 -130 to + 105 Fahrenheit.Fahrenheit.

• Only known place Only known place that supports life.that supports life.

• Abundance of water. Abundance of water. Should really be Should really be named “Ocean” not named “Ocean” not “Earth”“Earth”

• Only planet known Only planet known to have “plate to have “plate tectonics.” That tectonics.” That means the crust means the crust floats around on the floats around on the semi-molten mantel.semi-molten mantel.

• This gives earth a This gives earth a young surface with young surface with lots of active lots of active volcanoes.volcanoes.

• Axis is tilted 23 Axis is tilted 23 degrees.degrees.

• Earth has one Earth has one moon.moon.

• Our moon is Our moon is huge compared huge compared to the size of to the size of our planet our planet (1/3 (1/3 diameter).diameter).

• Created when a Created when a small planet hit small planet hit the Earth in the Earth in ancient times.ancient times.

• Almost non-Almost non-existent existent atmosphere.atmosphere.

• No life.No life.• Only celestial Only celestial

body man has body man has walked on walked on besides Earth.besides Earth.

• The ancient collision The ancient collision with Earth has been with Earth has been called “the lucky strike.”called “the lucky strike.”

• Earth without the moon Earth without the moon would have weak tides.would have weak tides.

• Might be water covered Might be water covered with no land.with no land.

• Day would only be 8 Day would only be 8 hours long. High winds. hours long. High winds. No seasons.No seasons.

• Primitive life or no life.Primitive life or no life.

• 44thth planet from sun planet from sun (1 ½ AU).(1 ½ AU).

• 4,221 miles in 4,221 miles in diameter. diameter. (1/2 that of (1/2 that of Earth)Earth)

• Year =687 earth days.Year =687 earth days.• Day = 24hours, 37 Day = 24hours, 37

mins.mins.• Two small moons: Two small moons:

Phobos & Deimos.Phobos & Deimos.

• When astronomers When astronomers first looked at Mars first looked at Mars they thought they they thought they saw “canals” on saw “canals” on the surface and the surface and changes that changes that suggested seasons suggested seasons and plant life.and plant life.

• Percival Lowell Percival Lowell even proposed the even proposed the canal were built by canal were built by intelligent Martians.intelligent Martians.

• Writers have Writers have speculated speculated about life on about life on Mars.Mars.

• War of the War of the World by H.G. World by H.G. Wells.Wells.

• Edgar Rice Edgar Rice Burroughs Burroughs wrote about a wrote about a civilization on civilization on Mars.Mars.

• Even I did a Even I did a book with book with featuring an featuring an alien from alien from Mars…Mars…

• Better observations Better observations over time show no over time show no canals.canals.

• Mars has a thin Mars has a thin atmosphere of atmosphere of carbon dioxide.carbon dioxide.

• Mars is cold. Avg. Mars is cold. Avg. temp -67 temp -67 Fahrenheit. (About Fahrenheit. (About as cold as Earth as cold as Earth arctic regions).arctic regions).

• Asteroids are small rocky Asteroids are small rocky bodies that orbit the sun.bodies that orbit the sun.

• Most are located in a belt Most are located in a belt that is that is 2-4 AU 2-4 AU from sun.from sun.

• They are too small to be They are too small to be round like planet.round like planet.

• Several hundred thousand Several hundred thousand asteroids have been found.asteroids have been found.

• If all the asteroids in the If all the asteroids in the solar system were put solar system were put together they would be together they would be smaller than our moon.smaller than our moon.

• Giuseppe Piazzi discovered Giuseppe Piazzi discovered the first asteroid, Ceres, in the first asteroid, Ceres, in 1801. 1801.

• At first it was considered a At first it was considered a planet until the thousands planet until the thousands of other objects around it of other objects around it were discovered and were discovered and named asteroids.named asteroids.

• Ceres itself was reclassified Ceres itself was reclassified as a as a dwarf planetdwarf planet in 2006, in 2006, though some still consider though some still consider it an asteroid. it an asteroid.

Near Earth AsteroidsNear Earth Asteroids• Most asteroids stay Most asteroids stay

in the belt, but in the belt, but some do approach some do approach Earth.Earth.

• Small ones become Small ones become meteorsmeteors if the enter if the enter Earth’s atmosphere Earth’s atmosphere and and meteoritemeteorites if s if they hit the ground.they hit the ground.

• Large ones can be Large ones can be dangerous to Earthdangerous to Earth

• An asteroid named An asteroid named Chicxulub is often Chicxulub is often cited as the reason cited as the reason for the dinosaurs for the dinosaurs extinction.extinction.

• Chicxulub is Chicxulub is thought to be 6 to thought to be 6 to 12 miles across.12 miles across.

• It made a crater It made a crater 130 miles in 130 miles in diameter.diameter.

• 55thth planet from the Sun planet from the Sun (5 AU)(5 AU)

• Largest planet in solar Largest planet in solar system – 88,846 miles system – 88,846 miles in diameter. in diameter. (11 times (11 times the diameter of Earth)the diameter of Earth)

• Year=12 Earth years. Year=12 Earth years. Day=9 hours, 55min.Day=9 hours, 55min.

• It is a It is a gas giant gas giant planet. planet. Has no solid surface, Has no solid surface, but is composed of but is composed of gas.gas.

• Temperature: -162 Temperature: -162 Fahrenheit.Fahrenheit.

• Jupiter is mostly Jupiter is mostly composed of composed of hydrogen gas.hydrogen gas.

• Its most noticeable Its most noticeable feature is the feature is the “Great Red Spot”“Great Red Spot”

• The spot is a The spot is a storm that has storm that has been raging for at been raging for at least 300 years least 300 years and could hold two and could hold two Earths.Earths.

• Galileo discovered Galileo discovered Jupiter’s four biggest Jupiter’s four biggest moons in 1610: moons in 1610: Io, Io, Europa, Ganymede Europa, Ganymede and Callisto.and Callisto.

• Jupter has 16 named Jupter has 16 named moons, but probably moons, but probably many more small many more small ones not named or ones not named or confirmed.confirmed.

• Is of special interest Is of special interest because it appears to because it appears to have a frozen icy surface have a frozen icy surface with liquid water with liquid water underneath.underneath.

• Water is kept warm by Water is kept warm by tidal forces.tidal forces.

• One of the few places One of the few places besides Earth with large besides Earth with large amount of liquid water.amount of liquid water.

• Scientists speculate Scientists speculate about life in the water.about life in the water.

SaturnSaturn• 66thth planet from sun planet from sun

(10 AU).(10 AU).• A gas giant A gas giant 74,897 74,897

miles in diameter miles in diameter (10 times the (10 times the diameter of Earth).diameter of Earth).

• Year = 29 ½ Earth Year = 29 ½ Earth years. Day 10 years. Day 10 hours.hours.

• Most noticeable Most noticeable feature are its feature are its rings.rings.

• 18 named moons.18 named moons.• Temperature -Temperature -

360 F360 F

• 77thth planet from sun (19 planet from sun (19 AU)AU)

• A gas giant 31,763 A gas giant 31,763 miles in diameter miles in diameter (4 (4 times that of earth)times that of earth)

• Its rotates on its side.Its rotates on its side.• Year = 84 Earth years. Year = 84 Earth years.

Day = 17 hoursDay = 17 hours• 27 named moons.27 named moons.• Temperature –355 FTemperature –355 F• Discovered by William Discovered by William

Herschel in 1781Herschel in 1781

• 88thth planet from sun. planet from sun. (30 AU).(30 AU).

• Temperature -400 F.Temperature -400 F.• A gas giant planet.A gas giant planet.• Year = 164 Earth Year = 164 Earth

years. Day = 16.11 years. Day = 16.11 hourshours

• Diameter is 30,777 Diameter is 30,777 miles (4 times that of miles (4 times that of Earth)Earth)

• 8 moons8 moons

• Predicted first in 1845 Predicted first in 1845 by Englishman John by Englishman John Couch Adams, but he Couch Adams, but he could not get anyone could not get anyone with a telescope to look with a telescope to look for it in the sky. for it in the sky. Eventually and Eventually and Frenchman Urbain Le Frenchman Urbain Le Verrier also predicted it Verrier also predicted it and the two had to and the two had to share the credit.share the credit.

• A belt of asteroids A belt of asteroids out beyond Neptune out beyond Neptune (30 to 50 AU).(30 to 50 AU).

• Also contains dwarf Also contains dwarf planets like Pluto, planets like Pluto, ErisEris(right), (right), Makemake Makemake and Haumeaand Haumea

• Belt also contains Belt also contains comets.comets.

• Small bodies “dirty Small bodies “dirty snowballs” that mostly snowballs” that mostly reside in the Kuiper belt reside in the Kuiper belt or further out in the or further out in the Oort Cloud.Oort Cloud.

• Some are on an Some are on an elongated orbit that elongated orbit that brings them though the brings them though the inner solar system and inner solar system and near the sun.near the sun.

• As they get close to the As they get close to the sun the ice melts an sun the ice melts an the comet gets a tail.the comet gets a tail.

• The inhabitants of Earth feared their The inhabitants of Earth feared their planet passing through a comet’s tail planet passing through a comet’s tail in 1910. Discuss the following:in 1910. Discuss the following:– Why have people always feared comets?Why have people always feared comets?– What especially in 1910 concerned What especially in 1910 concerned

them?them?– Do you think their fears reasonable?Do you think their fears reasonable?– Do you think there any way a comet Do you think there any way a comet

could do damage on earth?could do damage on earth?– Without comets would there be life on Without comets would there be life on

Earth?Earth?