Planets, Dwarf Planets and Moons of our Solar

System

Terrestrial Planets

Jovian Planets

TERRESTRIAL JOVIAN

• made of solid surfaces• much smaller than the

jovian planets• Atmosphere composed

mainly of carbon dioxide and nitrogen

• Core is less dense• Closer to the sun• Fewer moons

• made of gaseous surfaces• much larger than the

terrestrial planets• Atmosphere composed

mainly of helium and hydrogen

• Core is more dense• Farther from the sun• More moons

Mercury: -named after the god of speed for its quick revolution•Second smallest planet•Diameter = 3,029 miles

•Barely any atmosphere because low gravity and sun’s heat burns away•Heavily cratered due to lack of atmosphere•Gases of thin atmosphere= 52% Oxygen, 39% Na, 8% He•800°F (day) / -290°F (night)

•28.6 million miles from sun•Aphelion= 43 million miles•Perihelion= 29 million miles

Area not mapped by Mariner 10

Matisse Crater

•Surface observations were made by the Mariner10, which passed close to Mercury in 1974-1975. More WILL be learned from the Messenger Mission in 2011 (Japan and Europe).

• Very thick iron core• Very dense planet• Iron creates a magnetic field

that is only 1% the strength of Earth’s magnetic field

• Explored by Mariner 10 in 1974, along with Venus

• Rotation Period = 59 Earth Days

• Revolution= 88 Earth days• 0 Moons• Gravity =.38 that of Earth

Image of frozen south pole taken from the Mariner 10 spacecraft

Venus- named after the Goddess of beauty for the way that it shines in the night sky

• known as Earth’s twin because identical in size & composition

• 67.2 million miles from sun• Diameter = 7,521 miles• 0 Moons• Rotation= 243 Earth days (Only Planet

whose day is longer than its year!) Orbit is almost a perfect circle rather than elliptical like others

• Revolution= 224.7 Earth days• Gravity= .9 that of Earth• Venus also does not have seasons

because its axis only tilts 2.6°

Venus is the brightest planet in the night sky due to its thick atmosphere. Can be seen in early morning or evening in the night sky.

Venus’s Atmosphere•Atmosphere is extremely dangerous

•96.5% Carbon Dioxide •3.5% nitrogen and trace gases

•The high amount of C02 causes extreme global warming from the Greenhouse Effect•Surface temperature = 867°F•The clouds(3 distinct, thick layers) are a very thick sulfuric acid.•pressure inside Venus’ atmosphere is equal to being at 3,000 ft deep in one of our oceans!•In 1978 and 1989 US Magellan missions used radar to map 98% if the surface of Venus

Venus’s Surface•interior of Venus is very similar to Earth, except for a rocky mantle. •molten iron and nickel outer core and solid iron and nickel inner core•formed 4.5 billion years ago with the same materials as Earth.•Venus is similar but does NOT have Plate Tectonics but its surface is covered in mountains, plains and very active volcanoes.•Over 20 probes have been sent to Venus to explore its atmosphere and surface!

Maat Mons, the largest volcano on Venus

(3 miles high)

Venus’s surface is covered in old lava flows from about

500mya.

Earth•93 million miles from the Sun•Gravity = 1.0•Rotation= 23.98 hours•Revolution= 365.26 days (this is why we have Leap Years)•Diameter =7, 926 miles•Have four distinct seasons due to 23.93° tilt•Molten mantle which allows for Plate Tectonics

EARTH

• Plate Tectonics not only create and change our surface but it volcanic eruptions created water on Earth!

• Only planet with H2O Water!• Only planet with specialized atmosphere that

protects the surface from impacts and radiation from sun.

• Extremely strong Magnetosphere• Atmosphere= 78% Nitrogen, 21% Oxygen• Only Planet with LIFE!

Mars- Named after the god of war for its red color

• 141.6 mill miles from the Sun• Surface Temperatures -195°F to 77°F• Diameter= 4,213 miles (About half

the size of Earth.)• 2 Moons (Deimos and Phobos) Both

moons of Mars are captured asteroids.

• Gravity= .38 that of Earth• Rotation= 24.63 hours• Revolution= 687 Earth days

The poles shift during seasons. The seasons

are caused by tilt in axis as well as eccentric

orbit!

MARS• Atmosphere= 95.3% Carbon

Dioxide, 2.7% Nitrogen, 1.6% Argon

• Atmosphere is extremely thin with a very cold and dry surface.

• Mars has very distinct North and South poles which are mainly carbon dioxide ice.

• Retrograde Motion- apparent backward motion of a planet

Mars’s thin atmosphere

Surface of Mars•Iron Oxide causes the reddish-brown appearance.•covered in steep valleys, craters and large volcanoes, rocks, sand dunes•contains the solar systems’ largest volcano- Olympus Mons (larger than Colorado!)•shows evidence that ancient water flows created valleys (now the surface is too cold for water in a liquid state)•poles are full of highlands and mountains as well a CO2 ice.

•experiences dust storms that cover the planet. (dust clouds can be 3000 ft high and last for weeks!)•The 2001 Mars Odyssey and Global Surveyors in 2003 explored Mars for our most recent data.

Valles Marineris lies on the equator of Mars and is almost 10 times longer and 3 times deeper than the Grand Canyon! This canyon was created over

3bya by shifting of Mars’s crust.

Jupiter•Largest planet- 2.5 x mass of all other 8 planets combined. •Distance from Sun-=483.6 mil. miles•Diameter= 88,846 miles (10 times the diameter of Earth and 318 times more massive than Earth)•Number of Moons= 60•Rotation= 99.3 hours (Quicker spin on axis than any other planet)•Revolution= 11.86 Earth years•Gravity= 2.64 times that of Earth•Difference of 47.3 million miles between Aphelion and Perihelion

The Great Red Spot- is a storm (hurricane) larger than Earth that has been rotating around the planet and as been observed for the past 340 years.

JUPITER

• Atmosphere=89.8% Hydrogen, 10.2% Helium• Temperature= -166°F• Rings= 2 faint rings- observed by the Galileo

spacecraft during its five year mission around the planet

• Solid core- of rock, metal and hydrogen compounds.

• Magnetic Field- larger and stronger than any other planet(20,000 times stronger than Earth’s), and actually causes Aurora on the poles of Jupiter!

Jupiter’s Interior

•Composition is mostly hydrogen, in the form of liquid.

•Under the cloud layers, when the pressure of the interior becomes high enough, the hydrogen changes to liquid hydrogen, which gradually changes further to liquid metallic hydrogen.

•The core of Jupiter is made out of heavier, rocky and metal elements.

•Electric currents exist in the metallic layer, these create Jupiter’s magnetic field.

JupiterJupiter and its most interesting moon, Io.

The strength of Jupiter’s gravity is enormous. In 1993 Jupiter ‘s gravity pulled apart the Levy9 comet and the pieces crashed into Jupiter, as seen above.

Jupiter’s Moons (Galilean Satellites -after their discoverer):1.Io- most volcanic object in solar system, orbit is only 42.5 hours around Jupiter2.Ganymede- largest moon in solar system, made of rock and carbon dioxide ice3.Callisto- much brighter than our moon (ice reflects more sunlight) darker regions are rock4.Europa- ice-covered ball of rock, average temp around -225°F, may have liquid seas under the ice which could have simplistic life forms!

Saturn

Hubble image of Saturn with an image of shadows created by some of Saturn’s orbiting moons.

•Distance from Sun= 888 mill miles•Temperature= -220 °F•Diameter= 74, 898 miles•Number of moons= 62•Rotation= 10.66 hours•Revolution= 29.46 Earth years•Gravity= 1.07 that of Earth•Atmosphere= 96.3% Hydrogen, 3.7% Helium and trace gases with ammonia ice near the cloud tops.

SATURN• Saturn can be observed from

Earth with a naked eye 10 months out of the year. It appears pale yellow due to the thick cloud layers (3 distinct layers).

• Saturn also experiences Auroras from the Sun’s solar wind that can been seen on its southern pole.

• Saturn's’ magnetic field is a 1000 X’s larger than the Earth’s!

Five space probes have been on missions to orbit this planet since 2004

•made up of collections of separate pieces of dirty water and rock particles•These pieces can range from microscopic pieces to larger than some houses•There are 7 major rings (each ring is made up of smaller rings called ringlets)•These particles reflect a lot of light creating a beautiful color display.•rings change as the moons move through them.•rings are paper thin, in comparison to the size of the planet.•Origin of rings is most likely an object that was shattered by an asteroid or a moon broken apart by Saturn’s gravity.

Saturn’s rings, taken by the Voyager probe

Saturn’s Rings

Titan- Saturn’s largest moon

• Titan- Saturn’s largest moon (larger than Mercury!)

• Discovered in 1655• Only moon with substantial

atmosphere, similar to a young Earth

• Very nitrogen and methane rich atmosphere

• Size of Mercury• Made of rock, ice and water• -292°F

In 2005, the orbiter Cassini sent a probe to examine the atmosphere of Triton

Uranus• Distance from the Sun= 1.78 bill miles• Cloud Temperature= -353°F• Diameter= 31,763 miles• Numbers of moons= 27• Rotation=17.24 hours• Revolution=84 Earth years• Gravity= .89 that of Earth (at cloud tops)• Twice as far from the sun than Earth• 4 times the size of the Earth• Retrograde revolution= Uranus has

retrograde revolution which means that it revolves the opposite direction of the other planets

*Due to a planet-size impact, Uranus’s axis has been know onto its side at a 98° tilt!*Uranus also has 11 rings

Uranus• Atmosphere= 82.5% Hydrogen,

15.2% Helium, and 2.3% Methane (small amount of methane creates the pale blue color)

• The surface is made up of methane, water and ammonia ice.

• Electrical currents in the ice create a magnetic field on Uranus.

• The interior is a rocky/icy core.• Seasons last for 21 years, due

to extreme tilt.• In 1986, Voyager 2 flew by

Uranus and provided detailed information about the planet.

•has many smaller moons with five major moons

•Most of the moons follow the retrograde revolution like Uranus.

•Most moons are made up of rock and ice.

Neptune-The Blue Planet

• Average distance from the sun= 2.8 billion miles

• Cloud Temperature= -320°F• Diameter= 30,760 miles

(about time s Earth)• Number of Moons= 13• Rotation= 16.11 hours• Revolution= 164.9 years• Gravity= 1.13 that of Earth• Atmosphere= 79% Hydrogen,

18% Helium 3% MethaneThe Great Dark Spot- is a hurricane like storm almost as big as Earth BUT the storm disappeared in 1994.

NEPTUNE• Does have seasons due to 28.3% tilt• Similar to Uranus, Neptune has a surface of

water and methane ice with a similar icy or rocky core.

• Neptune has six thin rings, microscopic material and difficult to see.

• Neptune was first discovered mathematically using the Universal law of Gravitation in 1846.

• Voyager 2 flew by Neptune in 1989 to provide the first detailed images of the blue planet.

• Triton was discovered 17 days after the planet’s own discovery

• Similar to our moon, Triton’s synchronous, only one side of Triton always faces Neptune.

• Triton also has a backward orbit• The surface of Triton is most likely ice

and rock with possibly a liquid core.• Triton also has nitrogen geysers,

caused by gas below the poles, which expand and erupt when heated by the sun.

Triton- Neptune’s only major moon

Pluto- A Dwarf PlanetWhy Dwarf Planets?• There are 3 Dwarf Planets in our Solar System; Pluto,

Eris (found in the Kupier Belt) and a very large asteroid called Ceres.

• What is a Planet?– In 2006 the International Astronomical Union define

a planet as an object that orbits the sun with sufficient mass and gravity.

– Dwarf Planets orbit the sun but do not clear their “neighborhood” and they are not a moon(satellite)

Pluto with its moon Charon, which is almost as big as Pluto.

Pluto now has 3 moons: Charon, Nix, and Hydra

Pluto• Average distance from Sun- 3.8 billion

miles• Temperature- -382°F• Diameter- 1,432 miles• 1 Moon- Charon (Diameter of 730

miles)• Atmosphere- 99.97% Nitrogen • Rotation= 6.38 days• Revolution= 248.6 years• Gravity- 1/8 that of Earth• Orbit- has a more elliptical and titled

orbit, (one reason for its declassification as a planet) This sometimes allows it to be closer to the sun than Neptune, making Neptune the farthest planet.

• Eccentricity: .25

Other Dwarf Planets:

Eris

•Ceres-located in the Asteroid Belt. It was discovered in 1801.•Some still consider Ceres just a very large asteroid rather than a dwarf planet

•Eris was discovered in 2003, this caused the controversy of Pluto because these two objects were the same size•White in color and 97 AU’s away•Has 1 moon•Eccentricity is .43

Ceres