Our Solar System An introduction to our planets

The Sun  At the Center (and we do go around it …..)  99.85% mass of Solar System  92% H / 8% He  Source of solar wind and space weather Image:

Inner Planets  “Terrestrial Planets”  Rocky  Dense  Metal cores (iron) Images: Lunar and Planetary Laboratory:

Asteroids Image:  “Minor planets” or “planetoids” less than 1000 km across  Asteroid Belt between Mars and Jupiter  Occasionally run into Earth and other planets (oops) Ida

Outer Planets  Large!  Gases and liquids  No solid surface  May have a small solid core  Tumultuous atmospheres - rapid winds, large storms  Rotate relatively quickly Image: Lunar and Planetary Laboratory:

Kuiper Belt  Disk of debris at the edge of our Solar System  Pluto is a KB Object (sorry!)  Source of short- period comets

MERCURY  Closest planet to the Sun, but not the hottest due to lack of an atmosphere  Smallest planet in the Solar System  Surface covered in craters, just like Earth's Moon; solid iron core(3/4) surrounded by liquid iron and silicate mantleEarth's Moon  Temperature (up to 350°c on its sunlit side and -170°c on its dark side)  One year lasts for only 88 Earth days  One day takes 59 Earth days

VENUS  For years, Venus was called Earth's Sister Planet or Twin  Named after the ancient Roman god of love  Very heavy atmosphere (97% CO 2, sulfuric acid clouds)  896 O F….that’s HOT!

EARTH  Three layers: core, mantle, crust  Atmosphere has five layers, which together serve to block harmful rays and insulate/regulate temperature  Only planet that we know of that is capable of sustaining life

MARS  About half the size of Earth, but is most Earth-like  Thin atmosphere is being blown away by Sun’s wind  Is reddish in color due to the iron oxide - commonly known as rust - that is in the soil.  Could possibly be made habitable by man

Asteroid Belt  Asteroids are left over materials from the formation of the Solar System. These materials were never incorporated into a planet because of their proximity to Jupiter's strong gravity.

JUPITER ✶ Largest planet (1320 Earths) ✶ Great Red Spot (immense storm) ✶ Most moons of all planets (63) ✶ Named after Roman god of lightning (king of the gods) ∗ Gas giant (huge atmosphere) ∗ Liquid rock core, liquid mantle, liquid nitrogen, hydrogen and helium gases

SATURN  Gas planet (least dense planet)  Structure is very similar to Jupiter  Atmosphere is also mostly hydrogen and helium  Great white spot(?)  Magnificent rings likely caused by a collision between two of its satellites

URANUS  Gas giant  Liquid rock core surrounded by an “ocean” of hydrogen, helium, and water, with small amounts of ammonia and methane  Bland, almost featureless atmosphere made of hydrogen, helium, methane and ammonia  Only planet that rotates on its side!  Named after Greek god of the heavens

Neptune  “Twin” of Uranus, except that its atmosphere has much more detail  Unique Great Dark Spot (not much known)  Named after the ancient Roman god of the sea

MercuryVenusEarthMarsJupiterSaturnUranusNeptune Mean distance from the sun (10 6 km) ,4302,8704,500 Period of revolution (years) Orbital speed (km/s)

Relationship between distance and speed MercuryVenusEarthMarsJupiterSaturnUranusNeptune Mean distance from the sun (10 6 km) ,4302,8704,500 Period of revolution (years) Orbital speed (km/sec)

Solar System Overview Image: Lunar and Planetary Laboratory: FYI … Distance Not To Scale …