Download What is a Planet

Terrestrial Planets
Planets,
Dwarf
Planets and
moons of our
Solar System
Jovian Planets
Mercury
•The smallest planet
•Diameter 3,029 miles (4,875Km)
•Rich in iron
•Barely any atmosphere because of
low gravity and sun’s heat burns it
away
•Heavily cratered due to lack of
atmosphere
•Gases of thin atmosphere= 52%
Oxygen, 39% sodium, 8% Helium
•800°F during the day, -290°F at night
•28.6 million miles(46 mill km) from sun
•Aphelion= 43 million miles
•Perihelion= 29 million miles
•Surface observations were made by
the Mariner10, which passed close to
Mercury in 1974-1975. More WILL be
learned from the Messenger Mission
this year (Japan and Europe).
Area not
mapped by
Mariner 10
Matisse Crater
Mercury-named after the god of speed for its quick
revolution
• Very thick iron core
• Very dense planet
• Iron creates magnetic
field but only 1% the
strength of Earth’s
magnetic field.
• Explored by Mariner 10 in
1974 and 1975, along
with Venus
• Rotation Period = 59
Earth Days
• Revolution= 88 Earth days
Image of frozen
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Moons
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WHY???
south pole taken
• Gravity =.38 that of Earth
from the Mariner
10 spacecraft
Venus- named after the Goddess of beauty for
the way that it shines in the night sky
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Also know as Earth’s twin because
identical in size and composition.
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67.2 mill miles (108.2 km) from sun
Diameter 7,521 miles (12, 401 km)
0 Moons
Rotation= 243 Earth days (Only Planet
that its day is longer than its year!)
The orbit is almost a perfect circle
rather than elliptical like all others
Revolution= 224.7 Earth days
Gravity= .9 that of Earth
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Venus is the brightest planet in the night sky •
due to its thick atmosphere. Can be seen in
early morning or evening in the night sky. •
Venus also does not have seasons
because its axis only tilts 2.6°
Venus’s Atmosphere
•Atmosphere is extremely dangerous
•96.5% Carbon Dioxide
•3.5% nitrogen and trace gases
•The high amount of carbon dioxide
causes extreme global warming from the
Greenhouse Effect.
•Surface temperatures 867°F
•The clouds(3 distinct layers of thick
clouds) are a very thick sulfuric acid.
•The pressure inside Venus’ atmosphere
is equal to being at 3,000 ft deep in one
of our oceans!
•In 1978, Pioneer-Venus and 1989
Magellan missions of the United States
used radar to map 98% if the surface of
Venus!
•2006 a European Probe was sent to
monitor Venus’s atmosphere for 1 and ½
years.
Venus’s Surface
•The interior of Venus is
believed to be very similar to
Earth, except for a rocky
mantle. It has a molten iron
and nickel outer core and
solid iron and nickel inner
core
•Also formed 4.5 billion years
ago with the same materials
as Earth.
•Venus is similar but does
NOT have Plate Tectonics.
•Although, Venus’s surface is
covered in mountains, plains
and very active volcanoes.
•Over 20 probes have been
sent to Venus to explore its
atmosphere and surface!
Maat Mons, the largest
volcano on Venus
(3 miles high)
Venus’s surface is
covered in old lava
flows from about
500mya.
Earth
•93 million miles (149.6 mill Km) from the Sun
•Gravity = 1.0
•Rotation= 23.93 hours
•Revolution= 365.26 days (this is why we have
Leap Years)
•Diameter =7, 926 miles (12, 756 Km)
•Have four distinct seasons due to 23.5° tilt
•Molten mantle which allows for Plate Tectonics
•Only planet with Plate Tectonics - not only
create and change our surface but its volcanic
eruptions helped create water on Earth!
•Only planet with H2O Water!
•Only planet with specialized atmosphere that
protects the surface from impacts and radiation
from sun.
•Extremely strong Magnetosphere
•Atmosphere= 78% Nitrogen, 21% Oxygen
•Only Planet with LIFE!
•Average Temp- 65°F
Mars- Named after the god of war for its red color
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141.6 mill miles (227.9 mill Km) from the Sun
Surface Temperatures -195°F to 77°F
Diameter= 4,213 miles (6,780 Km)- About half
the size of Earth.
2 Moons (Deimos and Phobos) Both moons of
Mars are captured asteroids.
Gravity= .38 that of Earth
Rotation= 24.63 hours
Revolution= 687 Earth days
Atmosphere= 95.3% Carbon Dioxide, 2.7%
Nitrogen, 1.6% Argon
Atmosphere is extremely thin with a very cold
and dry surface.
Mars has very distinct North and South poles
which are mainly carbon dioxide ice.
Retrograde Motion- apparent backward
motion of a planet in the night sky.
retrograde 2
RETROGRADE MOTION
The poles shift during
seasons. The season
are caused but tilt in
axis as well as eccentric
orbit!
Mars’s thin
atmosphere
Surface of Mars
•Iron Oxide in the soil causes the reddishbrown appearance.
•Mars’s surface is covered in steep valleys,
craters and large volcanoes.
•Mars’s contains the solar systems’ largest
volcano- Olympus Mons (larger than
Colorado!)
•Mars does show evidence of ancient
water flows in which water created
valleys. But now the surface is too cold
for water in a liquid state.
•The surface is covered in rocks and sand
dunes.
•The poles are full of highlands and
mountains as well as carbon dioxide ice.
•The planet also experiences dust storms
that cover the planet. The dust clouds
can be 3000 ft high and last for weeks!
•The 2001 Mars Odyssey and Global
Surveyors in 2003 explored Mars for our
most recent data.
Valles Marineris lies on the equator of Mars and is
almost 10 times longer and 3 times deeper than
the Grand Canyon! This canyon was created over
3bya by shifting of Mars’s crust.
Jupiter
•Largest planet- 2.5 times the mass of all other 8 planets
combined.
•Distance from Sun-=483.6 million miles
•Diameter= 88,846 miles (10 times the diameter of Earth
and 318 times more massive than Earth)
•Number of Moons= 63
•Rotation= 99.3 hours (Quicker spin on axis than any
other planet)
•Revolution= 11.86 Earth years
•Gravity= 2.64 times that of Earth
•Difference of 47.3 million miles between Aphelion and
Perihelion
•Atmosphere=89.8% Hydrogen, 10.2% Helium
•Temperature= -166°F
•Rings= 2 faint rings- observed by the Galileo spacecraft
during its five year mission around the planet
•Solid core- of rock, metal and hydrogen compounds.
•Magnetic Field- larger and stronger than any other
planet(20,000 times stronger than Earth’s), and actually
causes Aurora on the poles of Jupiter!
The Great Red Spot- is a storm
(hurricane) larger than Earth that has
been rotating around the planet and as
been observed for the past 340 years.
Jupiter’s Interior
•The composition of Jupiter's interior
is mostly the simple molecules
hydrogen, in the form of liquid.
•Under the cloud layers, when the
pressure of the interior becomes high
enough, the hydrogen of which
Jupiter is made changes to liquid
hydrogen, which gradually changes
further to liquid metallic hydrogen.
•The core of Jupiter is made out of
heavier, rocky and metal elements.
•Electric currents exist in the metallic
layer, these create Jupiter’s magnetic
field.
Jupiter
Jupiter and its most interesting moon, Io.
Jupiter’s Moons (Galilean Satellites -after their discoverer):
1. Io- most volcanic object in solar system, orbit is only 42.5
hours around Jupiter
2. Ganymede- largest moon in solar system, made of rock
and carbon dioxide ice
3. Callisto- much brighter than our moon (ice reflects more
sunlight) darker regions are rock
4. Europa- ice-covered ball of rock, average temp around 225°F, may have liquid seas under the ice which could
have simplistic life forms!
The strength of Jupiter’s
gravity is enormous. In
1993 Jupiter ‘s gravity pulled
apart the Levy9 comet and
the pieces crashed into
Jupiter, as seen above.
Saturn
Hubble image of Saturn with an image
of shadows created by some of Saturn’s
orbiting moons.
Five space probes have been on missions
to orbit this planet since 2004
•Distance from Sun= 888 mill miles
•Temperature= -220 °F
•Diameter= 74, 898 miles
•Number of moons= 62
•Rotation= 10.66 hours
•Revolution= 29.46 Earth years
•Gravity= 1.07 that of Earth
•Atmosphere= 96.3% Hydrogen, 3.7%
Helium and trace gases with ammonia ice
near the cloud tops.
•Saturn can be observed from Earth with
a naked eye 10 months out of the year. It
appears pale yellow due to the thick
cloud layers (3 distinct layers).
•Saturn also experiences Auroras from
the Sun’s solar wind that can been seen
on its southern pole.
•Saturn's’ magnetic field is a 1000 X’s
larger than the Earth’s!
Saturn’s Rings
Titan- Saturn’s largest moon
•Saturn’s Rings (Image taken by Voyager Probe)
•Saturn’s rings are made up of collections of separate
pieces of dirty waters and rock particles.
•These pieces can range from microscopic pieces to
larger than some houses.
•There are 7 major rings and each ring is made up of
smaller rings called ringlets.
•These particles reflect a lot of light presenting a
beautiful color display.
•These rings change as the moons move through
them.
•Saturn’s rings are paper thin, in comparison to the
size of the planet.
•Origin of the rings is most likely an object that was
shattered by an asteroid or a moon broken apart by
Saturn’s gravity.
Saturn’s rings,
taken by the
Voyager probe
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Titan- Saturn’s largest moon (larger
than Mercury!)
Discovered in 1655
Only moon with substantial
atmosphere, similar to a young Earth
Very nitrogen and methane rich
atmosphere
Size of Mercury
Made of rock, ice and water
-292°F
In 2005, the
orbiter
Cassini sent
a probe to
examine the
atmosphere
of Triton
Uranus
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*Due to a planet-size impact, Uranus’s axis
has been know onto its side at a 98° tilt!
*Uranus also has 11 rings
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Distance from the Sun= 1.78 bill
miles
Cloud Temperature= -353°F
Diameter= 31,763 miles
Numbers of moons= 27
Rotation=17.24 hours
Revolution=84 Earth years
Gravity= .89 that of Earth (at
cloud tops)
Twice as far from the sun than
Earth
4 times the size of the Earth
Retrograde revolution= Uranus
has retrograde revolution which
means that it revolves the
opposite direction of the other
planets
Uranus
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•Uranus has many smaller moons
with five major moons.
•Most of the moons follow the
retrograde revolution like Uranus.
•Most moons are made up of rock
and ice.
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Atmosphere= 82.5% Hydrogen,
15.2% Helium, and 2.3% Methane
(small amount of methane
creates the pale blue color)
The surface is made up of
methane water and ammonia ice.
Electrical currents in the ice
create a magnetic field on
Uranus.
The interior is a rocky/icy core.
Seasons last for 21 years, due to
extreme tilt.
In 1986, Voyager 2 flew by Uranus
and provided detailed
information about the planet.
Neptune-The Blue
Planet
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The Great Dark Spot- is a hurricane
like storm almost as big as Earth BUT
the storm disappeared in 1994.
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Average distance from the sun= 2.8 billion
miles
Cloud Temperature= -320°F
Diameter= 30,760 miles (about time s Earth)
Number of Moons= 13
Rotation= 16.11 hours
Revolution= 164.9 years
Gravity= 1.13 that of Earth
Atmosphere= 79% Hydrogen, 18% Helium
3% Methane
Does have seasons due to 28.3% tilt
Similar to Uranus, Neptune has a surface of
water and methane ice with a similar icy or
rocky core.
Neptune has six thin rings, microscopic
material and difficult to see.
Neptune was first discovered
mathematically using the Universal law of
Gravitation in 1846.
Voyager 2 flew by Neptune in 1989 to
provide the first detailed images of the blue
planet.
Neptune and its moons
Triton- Neptune’s only major moon
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Triton was discovered 17 days
after the planet’s own discovery
Similar to our moon, Triton’s
synchronous, only one side of
Triton always faces Neptune.
Triton also has a backward orbit
The surface of Triton is most likely
ice and rock with possibly a liquid
core.
Triton also has nitrogen geysers,
caused by gas below the poles,
which expand and erupt when
heated by the sun.
Pluto- A Dwarf Planet
Pluto with its moon Charon,
which is almost a big a Pluto.
Why Dwarf Planets?
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There are 4-5 Dwarf Planets in our
Solar System; Pluto, Eris, Makemake,
Haumea ( Eris, Makemake, Haumea
are all found in the Kupier Belt) and
a very large asteroid called Ceres.
What is a Planet?
– In 2006 the International
Astronomical Union define a
planet as an object that orbits
the sun with sufficient mass
and gravity to pull itself into
sphere and clear its
“neighborhood” of other
objects.
– Dwarf Planets orbit the sun but
do not clear their
“neighborhood” and they are
not a moon(satellite)
Pluto (The Dwarf Planet)
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Average distance from Sun- 3.8 billion
miles
Temperature- -382°F
Diameter- 1,432 miles
1 Moon- Charon (Diameter of 730
miles)
Atmosphere- 99.97% Nitrogen
Rotation= 6.38 days
Revolution= 248.6 years
Gravity- 1/8 that of Earth
Orbit- Pluto has a more elliptical and
titled orbit, one of the reasons its lost
identification as a planet. This tilted
orbit sometimes allows it to be closer
to the sun than Neptune, making
Neptune the further most planet.
Eccentricity: .25
Other Dwarf Planets:
Ceres
•Ceres-located in
the Asteroid Belt. It
was discovered in
1801.
•Some still
consider Ceres
just a very large
asteroid rather
than a dwarf planet
Eris
•Eris was discovered
in 2003, this caused
the controversy of
Pluto because these
two objects were the
same size
•White in color and 97
AU’s away
HUBBLE PHOTO
•Has 1 moon
•Eccentricity is .43
•Makemake and Haumea are the 2
newest additions to the solar system.
They are both located in the Kuiper
Belt. Haumea actually has 2 of its
own moons.
Artist
drawings of
the 2 new
dwarf planets