a page for ppt on terrestrial planets grade 6

science ppt

1. The Terrestrial PlanetsThe Terrestrial Planets
A terrestrial planet, telluric planet or rocky
planet is a planet that is composed primarily of
silicate rocks or metals.
The terms are derived from The terms are derived from LatinLatin words words
for for EarthEarth ( (TerraTerra and and TellusTellus), as these planets ), as these planets
are, in terms of composition, "Earth-like".are, in terms of composition, "Earth-like".

2. Why are the Terrestrial Planets Why are the Terrestrial Planets
so different?so different?
"Terrestrials and jovians differ from each "Terrestrials and jovians differ from each
other in a number of ways. Some of the other in a number of ways. Some of the
most significant are:most significant are:
DiameterDiameter
The jovian planets are much larger than the The jovian planets are much larger than the
terrestrials: the smallest jovian planet is nearly terrestrials: the smallest jovian planet is nearly
four times larger in diameter than Earth, the four times larger in diameter than Earth, the
largest of the terrestrials.largest of the terrestrials.

3. Continuation…Continuation…
 MassMass
The jovian planets are all much more massive than The jovian planets are all much more massive than
the terrestrials: the least massive jovian contains 15 the terrestrials: the least massive jovian contains 15
times as much mass as the Earth (and Earth is the times as much mass as the Earth (and Earth is the
most massive of the terrestrials.)most massive of the terrestrials.)
DensityDensity
All of the terrestrial planets are rocky/metallic worlds All of the terrestrial planets are rocky/metallic worlds
with an aggregate average density about five times with an aggregate average density about five times
that of liquid water (so that a pint jar of typical that of liquid water (so that a pint jar of typical
terrestrial stuff would weigh about five pounds.) The terrestrial stuff would weigh about five pounds.) The
jovians, although large and massive, are rather jovians, although large and massive, are rather
"puffy": they all have very low densities, about equal "puffy": they all have very low densities, about equal

4. Continuation…Continuation…
to that of liquid water. This property tells us that jovian to that of liquid water. This property tells us that jovian
planets cannot be primarily solid -- instead, most of planets cannot be primarily solid -- instead, most of
their mass is in the form of liquid hydrogen.their mass is in the form of liquid hydrogen.
Chemical CompositionChemical Composition
The jovians seem to have about the same chemical The jovians seem to have about the same chemical
composition (by element) as the Sun: 75% hydrogen, composition (by element) as the Sun: 75% hydrogen,
24% helium, and only 1% everything else. The 24% helium, and only 1% everything else. The
terrestrials, however, being unable to hold on to the terrestrials, however, being unable to hold on to the
lightest gases gravitationally, have very little hydrogen lightest gases gravitationally, have very little hydrogen
and helium, and are made mostly of much heavier and helium, and are made mostly of much heavier
elements. The most abundant atom in the body of the elements. The most abundant atom in the body of the
Earth, for example, is oxygen (mostly locked up in Earth, for example, is oxygen (mostly locked up in

5. Continuation…Continuation…
molecules with other elements), each atom of which molecules with other elements), each atom of which
weighs 16 times as much as each hydrogen atom weighs 16 times as much as each hydrogen atom
does.does.

6. Continuation…Continuation…
Number of Natural Satellites (Moons)Number of Natural Satellites (Moons)
The terrestrial planets are almost devoid of natural The terrestrial planets are almost devoid of natural
satellites: Mercury and Venus have none, Earth only satellites: Mercury and Venus have none, Earth only
one, and Mars only two very tiny ones -- and those one, and Mars only two very tiny ones -- and those
latter two are probably captured asteroids. Jovian latter two are probably captured asteroids. Jovian
planets have a large number of satellites each, and planets have a large number of satellites each, and
exactly how many they have depends on how small exactly how many they have depends on how small
an object one is willing to call a "moon." At least six of an object one is willing to call a "moon." At least six of
the satellites in the outer solar system are larger than the satellites in the outer solar system are larger than
Pluto, and one is bigger than Mercury.Pluto, and one is bigger than Mercury.

7. Continuation…Continuation…
Rotation RatesRotation Rates
The jovian planets rotate (spin) more rapidly than do the The jovian planets rotate (spin) more rapidly than do the
terrestrials. The slowest-rotating jovian planet, Uranus, has terrestrials. The slowest-rotating jovian planet, Uranus, has
a rotation period that's less than 18 hours long; Earth's 24-a rotation period that's less than 18 hours long; Earth's 24-
hour period is the shortest among the terrestrials (and hour period is the shortest among the terrestrials (and
Venus takes 243 times longer than that for one full spin!) Venus takes 243 times longer than that for one full spin!)
Jupiter is so big and spinning so fast that its equator is Jupiter is so big and spinning so fast that its equator is
moving about 25,000 miles per hour relative to the center moving about 25,000 miles per hour relative to the center
of the planet: this, combined with Jupiter's primarily liquid of the planet: this, combined with Jupiter's primarily liquid
interior, makes Jupiter noticeably oblate (flattened), with a interior, makes Jupiter noticeably oblate (flattened), with a
polar diameter that's only about 90% as big as its polar diameter that's only about 90% as big as its
equatorial diameter.equatorial diameter.

8. Continuation…Continuation…
Distance from the SunDistance from the Sun
All of the jovian planets are farther from the Sun than All of the jovian planets are farther from the Sun than
the terrestrials are. This probably accounts for the the terrestrials are. This probably accounts for the
differences in chemical composition: the inner planets differences in chemical composition: the inner planets
had their original hydrogen and helium atmospheres had their original hydrogen and helium atmospheres
"blasted away," perhaps, by the early Sun's heat. The "blasted away," perhaps, by the early Sun's heat. The
differences in chemical composition, in turn, may differences in chemical composition, in turn, may
account for the differences in mass and diameter account for the differences in mass and diameter
(since hydrogen and helium are the most abundant (since hydrogen and helium are the most abundant
elements in the universe) and in density."elements in the universe) and in density."

9. References: References:
http://planet.fhda.edu/DACAstr/Harr4s/Tehttp://planet.fhda.edu/DACAstr/Harr4s/Te
……
http://en.wikipedia.org/wiki/Terrestrial_planhttp://en.wikipedia.org/wiki/Terrestrial_plan
etet
http://en.wikibooks.org/wiki/General_Astrohttp://en.wikibooks.org/wiki/General_Astro
nomy/The_Terrestrial_Planetsnomy/The_Terrestrial_Planets

10. END… END… 

11. MercuryMercury
FeaturesFeatures
Heavily crateredHeavily cratered
Features similar to Moon but greater in scaleFeatures similar to Moon but greater in scale
Scarps and marias aboundScarps and marias abound
Planet changes in size due to massive heating and Planet changes in size due to massive heating and
coolingcooling
Will likely break apart in futureWill likely break apart in future
Orbital NotesOrbital Notes
Rapid revolution (88 days) but slow rotation (59 days)Rapid revolution (88 days) but slow rotation (59 days)

12. MercuryMercury
AtmosphereAtmosphere
No atmosphere due to low gravity and solar windsNo atmosphere due to low gravity and solar winds
No atmosphere allows for severe day/night No atmosphere allows for severe day/night
temperature changestemperature changes
Day: 800Day: 800
oo
F, Night: -280F, Night: -280
oo
FF
ExplorationExploration
Very difficult to examine due to proximity to sunVery difficult to examine due to proximity to sun
Mariner 10 flyby in 1974Mariner 10 flyby in 1974
MESSENGER currently on siteMESSENGER currently on site
Rendezvous in 2009Rendezvous in 2009

13. VenusVenus
FeaturesFeatures
Completely covered in cloudsCompletely covered in clouds
Radar mapping required to graph surfaceRadar mapping required to graph surface
Comparable to Earth in size, density and massComparable to Earth in size, density and mass
High degree of erosional and volcanic processes at High degree of erosional and volcanic processes at
workwork
Surface dominated by lava flows and shield volcanosSurface dominated by lava flows and shield volcanos
Only 8% of planet considered highlandsOnly 8% of planet considered highlands
Orbital NotesOrbital Notes
Slowest rotating planet (244 days)Slowest rotating planet (244 days)
Revolution is 225 daysRevolution is 225 days
Rotational pattern is Rotational pattern is retrograderetrograde

14. VenusVenus
AtmosphereAtmosphere
Thick atmosphereThick atmosphere
Consists of 97% COConsists of 97% CO
22
Surface pressure 90x greater than EarthSurface pressure 90x greater than Earth
Day and night temperature changes almost non-existant in Day and night temperature changes almost non-existant in
spite of slow rotationspite of slow rotation
Average temp. 500Average temp. 500
oo
CC
ExplorationExploration
Originally thought to be “hospitable” due to Earth-like Originally thought to be “hospitable” due to Earth-like
appearanceappearance
Highly explored by both USSR and USAHighly explored by both USSR and USA
98% mapped by radar onboard Magellan in 199098% mapped by radar onboard Magellan in 1990
ESA currently in orbit with Venus ExpressESA currently in orbit with Venus Express

15. EarthEarth
FeaturesFeatures
Largest of the terrestrialsLargest of the terrestrials
Only known world with water appearing in all three Only known world with water appearing in all three
phasesphases
Only known world with carbon-based lifeOnly known world with carbon-based life
Only confirmed body with active tectonismOnly confirmed body with active tectonism
23.523.5
oo
axis tilt responsible for diverse seasons axis tilt responsible for diverse seasons
Unusually large moon (Luna)Unusually large moon (Luna)
Orbital NotesOrbital Notes
23.93 period of rotation23.93 period of rotation
365.25 period of revolution365.25 period of revolution

16. EarthEarth
AtmosphereAtmosphere
78% N78% N
22, 21%O, 21%O
22, 1-4% H, 1-4% H
22O, .94% Ar, .04 COO, .94% Ar, .04 CO
22
Divided into 4 distinct layers according to temperature Divided into 4 distinct layers according to temperature
profilesprofiles
Troposphere, Stratosphere, Mesosphere, ThermosphereTroposphere, Stratosphere, Mesosphere, Thermosphere
ExplorationExploration
First artificial craft launched in 1957First artificial craft launched in 1957
First animal into space 1957First animal into space 1957
First human into space 1961First human into space 1961
First landing on Luna 1969First landing on Luna 1969
Now over 6000 spacecraft in orbit around EarthNow over 6000 spacecraft in orbit around Earth

17. MarsMars
FeaturesFeatures
Very similar to rocky deserts on EarthVery similar to rocky deserts on Earth
Moderately contoured with certain massive featuresModerately contoured with certain massive features
No tectonic processes inferred in at least 1 BYNo tectonic processes inferred in at least 1 BY
Olympus MonsOlympus Mons
Massive shield volcanoMassive shield volcano
Largest in solar systemLargest in solar system
Valles MarinerisValles Marineris
Canyon as long as the USCanyon as long as the US
Over 3000 miles long and 5 miles deepOver 3000 miles long and 5 miles deep

18. MarsMars
Features (cont.)Features (cont.)
Origins of canyon systems under debateOrigins of canyon systems under debate
Block or tectonic faultingBlock or tectonic faulting
WaterWater
Polar capsPolar caps
Consist of layer of COConsist of layer of CO
22 with H with H
220 beneath0 beneath
Show high amount of seasonal changesShow high amount of seasonal changes

19. MarsMars
MoonsMoons
Two small moonsTwo small moons
Likely captured asteroidsLikely captured asteroids
Not discovered until 1977 due to small sizeNot discovered until 1977 due to small size
PhobosPhobos
24 km24 km
Very close to Mars and orbits in under 8 hoursVery close to Mars and orbits in under 8 hours
Orbit retrograde and too close to planetOrbit retrograde and too close to planet
Destruction likely within 50 million yearsDestruction likely within 50 million years
DeimosDeimos
17 km17 km

20. MarsMars
Orbital NotesOrbital Notes
Period of revolution, rotation and axis tilt very similar to Period of revolution, rotation and axis tilt very similar to
EarthEarth
Creates almost same hours of day/night Creates almost same hours of day/night
Seasonal changes similar to Earth but 2x as long Seasonal changes similar to Earth but 2x as long
AtmosphereAtmosphere
Very thin atmosphereVery thin atmosphere
Consists of COConsists of CO
22 and H and H
22O vaporO vapor
Only 1% that of EarthOnly 1% that of Earth
Planet wide dust storms commonPlanet wide dust storms common
Day temperatures can reach acceptable levels in summer but Day temperatures can reach acceptable levels in summer but
drops at night and in winter average -150drops at night and in winter average -150
oo
FF

21. MarsMars
ExplorationExploration
Always aroused interest due to easy viewing and Always aroused interest due to easy viewing and
popular culturepopular culture
Highly explored by both USSR and USAHighly explored by both USSR and USA
Represents present focus of NASA planetary Represents present focus of NASA planetary
explorationexploration
Several US probes currently in orbit or on the surfaceSeveral US probes currently in orbit or on the surface