Revolution vs. Rotation When a celestial body moves around a central point (orbit) Revolution is responsible for our SEASONS. Revolution is responsible for our YEARS. (1 full revolution = 1 Earth Year)

Revolution vs. Rotation The spinning motion around the axis of a celestial body Rotation is responsible for our DAYS / NIGHTS NIGHT DAYLIGHT DAY

Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune My Very Energetic Mother Just Served Us Nachos

Mercury Mass (Earth = 1) : 0.055 Revolution (year) : 87.97 days Rotation (day) : 58.65 days Moons : 0 Atmospheric Composition: Principally of helium and hydrogen with little amounts of sodium, oxygen, neon, argon and potassium Mercury has been visited by two spacecraft, Mariner 10 and MESSENGER.

Venus Mass (Earth = 1) : 0.81 Revolution (year) : 224.7 days Rotation (day) : 243.01 days* (Retrograde Rotation) Moons : 0 Atmospheric Composition: About 92% Carbon dioxide, 3.5% nitrogen The first spacecraft to visit Venus was Mariner 2 in 1962. It has been visited by many others (more than 20 in all so far).

Earth Mass (Earth = 1) : 1 Revolution (year) : 365.25 days Rotation (day) : 23.93 hours Moons : 1 Atmospheric Composition: 78% Nitrogen, 21% Oxygen and 1% water vapour, argon, carbon dioxide and other trace gases.

Mars Mass (Earth = 1) : 0.11 Revolution (year) : 1.88 years Rotation (day) : 24.62 hours Moons : 2 Atmospheric Composition: 95% Carbon dioxide, 2.7% Nitrogen, 1.6% Argon, 0.7% Oxygen, carbon monoxide and water vapor The first spacecraft to visit Mars was Mariner 4 in 1965. Several others followed. We Currently have 3 spacecraft on Mars, the Spirit, the Opportunity, and the Phoenix.

Jupiter Mass (Earth = 1) : 318 Revolution (year) : 11.86 years Rotation (day) : 9.92 hours Moons : over 30 Atmospheric Composition:90% Hydrogen, 10% Helium with traces of ammonia, methane and water vapor Jupiter was first visited by Pioneer 10 in 1973 and later by Pioneer 11, Voyager 1, Voyager 2 and Ulysses. The spacecraft Galileo orbited Jupiter for eight years.

One of the five deadliest storms in the history of the United States. Hurricane Katrina (2005) One of the five deadliest storms in the history of the United States. Highest Winds: 175 mph (280 km/h) Responsible for $81.2 billion in damages.

Storm has been occurring for over 300 years Highest Winds: 270mph It is a swirling gas mass of extremely cold temperatures (-121oC, -186oF)

Saturn Mass (Earth = 1) : 95.18 Revolution (year) : 29.46 years Rotation (day) : 10.67 hours Moons :18 Atmospheric Composition: 94% Hydrogen, 6% helium with traces of ammonia, methane and water vapor

Uranus Mass (Earth = 1) : 14.5 Revolution (year) : 84.01 years Rotation (day) : 17.23 hours* (Retrograde Revolution) Moons :15 Atmospheric Composition: 85% Hydrogen, 12% helium and 3% methane

Neptune Mass (Earth = 1) : 17.14 Revolution (year) : 164.79 years Rotation (day) : 16.12 hours Moons :8 Atmospheric Composition: 85% Hydrogen, 13% Helium and 2% methane

How small is Pluto?

Planets around Other Stars Current count (so far) Over 100 planetary systems Over 200 planets Over 20 multiple planet systems At least 15% of sun-like stars have planets