Brightness Order: Sun Moon Venus Mars Jupiter

Density Order: Earth, Mercury, Venus, Mars, Pluto, Neptune, Uranus, Jupiter, Saturn.

All planets rotate CCW when seen from Earth’s North Pole, except Venus, Uranus, and Pluto exhibit retrograde motion.

Generate more heat than receive from Sun:

Jupiter, Saturn, Metis, & Io.

Albedo: measure of reflectivity (1 brightest – 0 darkest)

4 moons have atmospheres: Io, Ganymede, Titan, Triton.

Volcanically Active: Earth, Venus, Io, Triton..

 

Mercury

·         Mariner 10 flew by 1974-75

·         3 rotations = 2 revolutions

·         Most extreme temperature variations

·         2nd densest after Earth

·         Caloris Basin 1300 km

·         Water Ice at poles

 

Venus

·         Most circular orbit

·         Phases seen from Earth

·         Visited by Mariner 2, Venera 1 & 2, Magellan.

·         Year longer than day.

·         Always the same face towards Earth at closest approach

·         90 times Earth’s atmospheric pressure

·         Sulphuric clouds

·         Atalanta, Guinevere, & Lavinia Planitia

·         Ishtar & Aphrodite Terra (Maxwell Monte)

·         Geologically active but quiet.

·         Retrograde motion

 

Moon

·         Visited by Clementine 1994, Lunar Prospector 1999

·         Maria – Impact craters flooded by lava flows

·         No magnetic field now

 

Mars

·         Mariner 4, Viking Landers (1976), Mars Pathfinder, Mars Global Surveyor

·         Olympus Mons – Highest mountain in Solar System

·         Vallis Marineris – 4000 km long system of canyons

·         Atmospheric pressure 1% of Earth’s

·         Atmosphere composed of 95% CO2, 3% O2, 1.6% Ar

·         Phobos and Deimos: Phobos smallest moon in the Solar System and closest to primary; most probably captured asteroids

 

Jupiter:

·         Pioneer 10, Voyager 1 & 2, Ulysses, and Galileo.

·         90% H, 10% He.

·         Composition like Saturn, not Uranus & Neptune

·         Radiates more energy than it receives

·         16 known moons

·         Inner moons MAAT:

o        Metis and Adrastrea orbit inside the main ring and the Roche limit

·         Galillean moons

o        Io – Slightly larger than the Moon

o        Io & Europa like terrestrial planets

o        Europa – 4th largest Jovian sat. Smaller than the Moon. Outer layer of ice. Weak atmosphere

o        Ganymede: Largest Jovian sat. Largest in the Solar System. Bigger than Mercury and Pluto.

o        Callisto: 2nd largest Jovian moon. Valhalla – Multi-ring impact craters

Saturn

·         Pioneer 10, Voyagers 1 & 2, Cassini.

·         Least dense

·         75% H, 25% He.

·         Radiates more than receives.

·         18 known moons

·         Mimes is dominated by craters

·         Rhea – second largest

·         Titan – 2nd largest in the Solar System; heavy N atmosphere, Hugenys probe from Cassini

 

Uranus

·         Larger in diameter but smaller in mass than Neptune

·         Primarily rock & ice; 15% H, little He.

·         21 moons

·         Tilted 90%, retrograde motion

·         Miranda

·         Triton – only large moon that retrogrades

 

Neptune

·         8 moons

·         Windiest planet

 

Esc velocity v = k Öm/R