Planet HighlightsPlanet Highlights

Mercury

MercuryMercury

Mercury• Highest DensityHighest Density

• Thinnest AtmosphereThinnest Atmosphere

• Highest Temperature and Highest Temperature and Greatest Temperature RangeGreatest Temperature Range

• Messenger will fly by in 2011 Messenger will fly by in 2011

• Surface is similar to the moonSurface is similar to the moon, , very cratered, oldvery cratered, old

VenusVenus

Venus• It’s It’s day is longer than its yearday is longer than its year

• Still volcanically active and Still volcanically active and covered with large lava flowscovered with large lava flows

• It has It has no moonsno moons

• Atmosphere is mostly Carbon Atmosphere is mostly Carbon Dioxide, which causes a large Dioxide, which causes a large Greenhouse EffectGreenhouse Effect, raising its , raising its temperaturetemperature

Venus: Earth’s TwinEarth’s Twin

• Similar in Similar in sizesize

• Similar Similar densitydensity

• Young, Young, volcanically activevolcanically active surfacesurface

• Probably used to have water Probably used to have water that boiled awaythat boiled away

MarsMars

Exploration of Mars• Has been explored more than any Has been explored more than any

other planet:other planet:– Mariner 4 visited for the first time in Mariner 4 visited for the first time in

19651965

– Landers include Mars 2, Viking, Landers include Mars 2, Viking, Pathfinder, Spirit, and OpportunityPathfinder, Spirit, and Opportunity

– 3 orbiters are currently in orbit3 orbiters are currently in orbit

We have learned a lot about the surface We have learned a lot about the surface of Mars as a resultof Mars as a result

Surface of Mars• Largest Mountain/Volcano in Solar Largest Mountain/Volcano in Solar

System: System: Olympus MonsOlympus Mons

Surface of Mars

• RockyRocky

• Evidence of erosion Evidence of erosion possibly by liquid possibly by liquid waterwater: Dry river : Dry river beds and canyonsbeds and canyons

• Volcanoes and lava Volcanoes and lava flowsflows

• Red PlanetRed Planet

Largest Canyon in solar system

• Would Would stretch stretch from New from New York to York to Los Los Angeles Angeles on earthon earth

Moons of Mars• 2 Moons2 Moons

–PhobosPhobos DeimosDeimos

Other Mars FactsOther Mars Facts• Very thin atmosphereVery thin atmosphere

• Permanent polar ice capsPermanent polar ice caps made of made of water and carbon dioxidewater and carbon dioxide

Asteroid BeltAsteroid Belt• The region between Mars and Jupiter The region between Mars and Jupiter

contains irregularly shaped rocky contains irregularly shaped rocky objects called asteroids.objects called asteroids.

AsteroidsAsteroids• Asteroids are probably left over Asteroids are probably left over

material from a planet that never material from a planet that never formed.formed.

• They range in size from 1000 km to They range in size from 1000 km to the size of a pebble.the size of a pebble.

• There are 26 large ones and There are 26 large ones and millions of smaller ones, although millions of smaller ones, although most of the asteroid belt is empty most of the asteroid belt is empty space.space.

JupiterJupiter• Gas Giant:Gas Giant: No solid surface, it’s gases No solid surface, it’s gases

just get more dense.just get more dense.

• Under the gases is a liquid metallic core Under the gases is a liquid metallic core (at high temperatures and pressures the (at high temperatures and pressures the hydrogen becomes a liquid with ionized hydrogen becomes a liquid with ionized protons and electrons that conduct protons and electrons that conduct electricity like a metal)electricity like a metal)

• Made mostly of Hydrogen and HeliumMade mostly of Hydrogen and Helium

• Rocky coreRocky core 10-15 times the mass of 10-15 times the mass of earthearth

Jupiter• Lots of Lots of

images from images from HubbleHubble

• Flyby in 1973 Flyby in 1973 by Pioneer, by Pioneer, VoyagerVoyager

• Orbited for 8 Orbited for 8 years by years by GalileoGalileo

Jupiter FactsJupiter Facts

• Has the Has the Great Red Spot- giant storm Great Red Spot- giant storm in its gasesin its gases

• Has Has faint ringsfaint rings

• Has Has 63 moons63 moons, 4 very large ones, 4 very large ones

• Was hit by a comet in 1994Was hit by a comet in 1994

• So big all of the other planets would So big all of the other planets would fit inside itfit inside it (diameter is 11 times that (diameter is 11 times that of earth)of earth)

Saturn• Gas GiantGas Giant containing a gas surface containing a gas surface

of mostly of mostly Hydrogen and HeliumHydrogen and Helium, a , a liquid hydrogen metal outer core, liquid hydrogen metal outer core, and a and a rocky inner corerocky inner core

• Has Has large, prominent ringslarge, prominent rings with with spaces between themspaces between them

• Cassini is orbiting since 2004Cassini is orbiting since 2004

• Voyager and Pioneer visitedVoyager and Pioneer visited

• 34 moons34 moons

Saturn• Saturn

has such a low low densitydensity it would float in water!

Titan- Saturn’s Moon

• Larger than Mercury and PlutoLarger than Mercury and Pluto

• Second largest moon in solar Second largest moon in solar systemsystem

• Has a planet-like atmosphereHas a planet-like atmosphere

• Has places on it that look like Has places on it that look like liquid-filled lakes (probably not liquid-filled lakes (probably not water)water)

Titan• We sent Cassini THROUGH We sent Cassini THROUGH

Saturn’s rings to orbit Titan. Saturn’s rings to orbit Titan. Then we dropped Huygens Then we dropped Huygens onto the surface of Titan. It onto the surface of Titan. It landed with the help of 3 landed with the help of 3 parachutes to slow it down parachutes to slow it down from 12,000 mphfrom 12,000 mph

• Found mud, rock, and liquidFound mud, rock, and liquid

UranusUranus

• Gas GiantGas Giant: It’s atmosphere has : It’s atmosphere has Hydrogen and Helium, but it’s Hydrogen and Helium, but it’s interior is rocky and icy. interior is rocky and icy.

• Only visited once by VoyagerOnly visited once by Voyager

• Rotates on it’s side with its south Rotates on it’s side with its south pole facing the sunpole facing the sun

• 11 rings11 rings

• 27 moons 27 moons

UranusUranus

Neptune• Sometimes its orbit crosses that of Sometimes its orbit crosses that of

Pluto, making it farther away from Pluto, making it farther away from the sun than Plutothe sun than Pluto

• Visited only once by VoyagerVisited only once by Voyager

• Gas GiantGas Giant with a Gas surface of with a Gas surface of hydrogen and helium, and then a hydrogen and helium, and then a rocky, icy corerocky, icy core

• 13 Moons and faint rings13 Moons and faint rings

Neptune

Pluto• Smaller than 7 moons in the solar Smaller than 7 moons in the solar

system and is now a system and is now a dwarf planetdwarf planet

• Very eccentric orbitVery eccentric orbit, so it crosses , so it crosses with Neptune with Neptune

• New Horizons, launched in 2006, New Horizons, launched in 2006, should flyby in 2015should flyby in 2015

• 3 moons, one almost as big as Pluto; 3 moons, one almost as big as Pluto; “Double Planet”“Double Planet”

PlutoPluto

Kuiper Belt• Region beyond Neptune with Region beyond Neptune with

small, icy objects that are the small, icy objects that are the source of cometssource of comets

• Sedna and other small planetoids Sedna and other small planetoids are located hereare located here