Planets and Our Solar System

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Planets and Our Solar System
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Our Solar System

• Our sun is the center of our solar system.
• 9 planets orbit our sun, including Earth.
• The planets are divided into two groups.
• Inner planets or Terrestrial Mercury, Venus,
  Earth and Mars
• Rocky crusts, dense mantel, very dense
  cores
• Separated by the Asteroid Belt
• Outer Planets or Gaseous Jupiter, Saturn,
  Uranus, Neptune, Pluto The first 4 (Jovian
  Planets) are larger than Earth, gaseous (mostly
  H), with hot liquid hydrogen (H) cores and ring
  structures.
• Pluto doesnt fit any of the categories, and well
  you know the debate about Pluto. Not dense
  enough to be like inner, not big enough like the
  gas planets.

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The Planets were NamedTo Pay Tribute to Greek
Roman Gods

• Mercury Messenger of the gods, a god w/wings on
  his ankles
• Venus Goddess of Love and Beauty
• Mars God of War
• Jupiter Leader of the ancient Roman gods.

• Saturn God of Agriculture
• Neptune God of the Sea
• Uranus God of the Sky
• Pluto God of Hades, the underworld of the Dead

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Mercury

• Nearest the Sun
• Orbits sun the fastest of all planets, 88 Earth
  days
• Smallest of the 4 terrestrial planets,
  38 the size of Earth
• Magnetic field is 1 of Earths strength

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Mariner 10

• 1974/75 Took Photographs
• Heavily cratered like our moon (Most abundant
  landform)
• Rest of land is smooth like as if lava flowed
  through cracks and spread everywhere.
• Very slow rotation on its axis, 59 Earth days
• 400 degrees Celsius in day and -200 degrees at
  night
• Weak gravity doesnt hold an atmosphere
  high temps. During day cause gas to escape
  into the atmosphere

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Venus

• Similar to Earth in diameter, mass, and gravity,
  however, unlike Earth it has a very low, almost
  nonexistent magnetic field.
• Orbits the sun in 225 Earth days, but it only
  rotates every 243 days. In other words, its year
  is shorter than its day.
• Thick pale yellow clouds.
• Magellan Spacecraft Radar mapping of Venus shows
  its terrain is similar to Earths.
• 80 is covered with lava flow
• Fault Fracture system
• Unknown if volcanic activity is still active
• Oldest known crust on Venus is estimated 800
  million years compared to Earth only 4.3 billion

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Venus Morning Star/Evening Star

• 1985 2 balloons carrying weather instruments were
  placed in Venuss atmosphere.
• Data showed the dense atmosphere is mostly CO2
  (carbon dioxide) and 3 nitrogen.
• Yellow clouds are made of droplets of
  concentrated sulfuric acid.
• Atmospheric pressure at the surface of Venus is
  90 times greater than Earth.
• CO2 acts as a greenhouse reaches 475 degrees
  Celsius.

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Mars

• 4th planet from the sun
• 687 days to orbit the sun ( almost twice of
  Earths)
• Diameter ½ of Earths
• 2/5 of Earths gravity
• Almost nonexistent magnetic field
• Tilt is similar to Earths so they have seasons.
• Colder than on Earth, hottest day 27C and winter
  -125C.
• Atmosphere is 95 CO2, 5 Argon and Nitrogen,
  traces of other gasses.
• Northern ice cap is probably frozen water and
  southern icecap is probably frozen CO2.
• Strong winds and dust storms

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Mars continued

• Cameras aboard several spacecrafts have
  photographed mars.
• We have recorded quakes, soil, and weather
  conditions on Mars.
• Northern hemisphere is smooth lowlands, and
  southern hemisphere is highlands fractured by
  many craters and channels.
• Many extinct volcanoes. Mt. Olympus (Olympus
  Mons) is highest volcano known in the solar
  system, 26 km tall and 500 km across.
• Unlike Earth volcanoes, there doesnt seem to be
  a correlation between plate movement and
  volcanoes. Instead Mars has only 1 detectable
  plate.
• Crust varies from 80 35 km thick.
• Valles Marineris, a canyon system as long as the
  U.S., may once have had water, but Mars lost its
  atmosphere disappeared. However some ice is
  trapped below the crust.
• Primitive life (akabacteria) may once have
  existed on Mars.

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Mars Explorations

NASA's 2003 Mars Exploration Rover (MER)
Mission is an ongoing unmanned Mars exploration
mission, commenced in 2003, that sent two
robotic rovers Spirit and Opportunity to
explore the Martian surface and geology.
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Asteroid Belt

• Asteroids are primordial objects left over from
  the formation of the Solar System.
• While some have suggested that they are the
  remains of a protoplanet that was destroyed in a
  massive collision long ago, the prevailing view
  is that asteroids are leftover rocky matter that
  never successfully coalesced into a planet.
• Most planetary astronomers still believe that the
  planets of the Solar System formed from a nebula
  of gas and dust and ices that coalesced into a
  dusty disk around the developing Sun.
• Within the disk, tiny dust grains coagulated
  into larger and larger bodies called
  planetesimals, many of which eventually accreted
  into planets over a period as long as a 100
  million years.

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Asteroid Belt

• On August 24, 2006, the International
  Astronomical Union voted at the end of its 26th
  General Assembly to establish a new class of
  substellar objects in the Solar System called
  "dwarf planets", which may eventually encompass
  the largest, relatively round asteroids such as
  Ceres and perhaps eventually Vesta, Pallas, and
  Hygeia.

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The Outer Planets

• Huge gaseous planets
• Ring Structures
• Many independent orbiting particles
• Closer to planet than planets moon
• Orbit the planet at planets equator
• Strange Moons
• Jovian Planets Jupiter Like Planets
• Extremely large compared to Inner planets
• Nothing solid about them
• Made up of light elements, H and He
• All have 3 layered system
• Temperature and density increase as you enter
  interior

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Jupiter

• 5th Planet from the sun
• 11.9 Earth years to complete 1 orbit around the
  sun.

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Jupiter cont.

• Strongest magnetic field in the solar system
• Solar wind and magnetic field create auroras like
  on Earth
• Great Red Spot is a giant hurricane
• Rotates in 10 Earth hours
• High velocity winds along equator
• 3600 Earths would fit in Jupiter

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Saturn

• 6th planet from the sun, 30 Earths would fit
  inside
• Rising and sinking gases cause wind
• Lowest density of any other planet (If your
  bathtub was big enough, Saturn could float in it.
• Radiates more heat than it absorbs from the sun.
• Rings are probably ice

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Uranus (Yur-uh-nus)

• 7th from sun
• 84 Earth years to complete one orbit
• Discovered late (1781) when telescopes advanced.
• axis of rotation is side ways and takes 17.2 hrs
• Magnetic field axis of rotation off 60?

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Neptune

• Most distant of Jovian planets
• Discovered in 1846
• Period of rotation is 16.1 Earth hours
• Period of Revolution is 165 years
• Magnetic field and axis of rotation off by 47?
• Possibly has water in its core which creates a
  magnetic field

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Neptune

• Wind has been clocked at 2000 km / hr
• Ave. temp -225?
• Atmosphere is mostly H 74
• He 25
• Methane (CH4) 1
• Crosses Pluto to be the 9th planet instead of the
  8th every 248 years and lasts for about 20 yrs

False color Image
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Pluto

• Discovered in 1930
• Remains the only planet that has not been visited
  by a spacecraft
• Smaller than the Earths moon 2300 km diameter
• Pluto's rotation period is 6.387 days, the same
  as its satellite, Charon
• Scientists guess it is about 70 terrestrial and
  30 water

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Satelites

• Moon is Earths only natural satelite
• Mars has 2 moons (both are irregularly shaped)
• Jupiter has 28 moons
• Largest are Io, Europa, Ganymede, Calisto
• Saturn has 24. Largest being Titan, atmosphere
  similar to Earths. Second largest moon in our
  solar system, -180 ?c

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Satelites continued

• Uranus has 21 moons
• Neptune has 8
• Pluto has 1

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Comets

• Dirty Snowballs
• Dust trapped in a mixture of water, methane, CO2,
  ammonia
• Spend most of their lives beyond neptune TNOs
• Trans Neptunian Objects

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Asteroids

• Solid, rocklike masses
• Irregular shapes
• Revolve around the sun like planets do
• 2 largest in space are
• Ceres
• Pallus

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• Meteors Shooting stars, in the atmosphere
• Meteoroids Ice or rock in orbit
• Meteorites If they dont burn up in atmosphere
  and make it to Earth as a rock
• Impact Crater Bowl-shaped depressions left by
  impact of Meteors.