Hành tinh trong hệ mặt trời

by:

Zarif Saabab
Planets
In our
Solar
System


Diameter: 4,880 km
Distance to Sun:
57,910,000 km (0.38 AU)
Orbital Period: 88 Days
Surface Area: 75,000,000
km2
Number of Moons: 0
Axial Tilt: 0.01º
Mercury is currently the
smallest planet in the so-
lar system. It is the also
the closest planet to the
sun. The time it takes for
one whole axial rotation
is 58 Earth days so within
two-axial rotation a whole
Mercurial year would pass.
Mercury can be mainly seen
in the sky during dawn or
dusk.
The name of the plan-
et comes from a Roman

winged messenger of the
gods because of its fast or-
bital speed around the sun
when compared to other
planets. Mercury has a very
thin atmosphere compris-
ing of only trace elements
of potassium, argon, and
oxygen. This is because
Mercury is closest planet
to the Sun and it is being
constantly being bombard-
ed by incredible amounts
of solar heat and radiation.
Mercury has a very wide
range of temperatures
from –183ºC to 425ºC al-
though it has an average
temperature of 170ºC.
Its surface mainly contains
rocks with high Iron con-
tent. Mercury has hundred
of large craters all over the
surface of the planet by
meteorites easily breaking
through the imsy atmos-
phere. Most of the planet
has not been mapped with
much detail, so its distin-
guishable characteristics

are not very well known.
The rst known observa-
tion of Mercury was over
5,000 years ago by an an-
cient civilization called the
Sumerians. Mercury has
an incredibly small axial
tilt being basically at right
angles to the Sun, so that
the Sun is always over the
equator at any time of its
year.
1
Mercury
Diameter: 12,100 km
Distance to Sun:
108,200,000 km (0.72 AU)
Orbital Period: 225 Days
Surface Area:
460,000,000 km2
Number of Moons: 0
Axial Tilt: 177.3º
Venus is the second plan-
et from the Sun and is the
closest planet to Earth,
with the closest distance
being 38,200,000 km. The
time it takes to make one
whole axial rotation is 243
Earth days, so that it takes

longer for Venus to make
an axial rotation than it
does to make a whole orbit
of the Sun.
Venus is sometimes bright
enough to be seen in the
day but during a clear night
Venus shines brighter than
any other star in the night
sky. The name of Venus
also comes from Roman
mythology, specically the
Roman goddess of love.
Its atmosphere comprises
of thick and dense carbon
dioxide as well as nitrogen
and sulfuric acids. Venus is
only one of two planets in
the solar system that has
a retrograde spin which
means that it spins in the
opposite directions on its
axis when compared to the
other planets.
The highest temperature
in Venus is 500ºC near the
equator of the planet, but
can get as low as 45ºC at
the cloud tops of the plan-
et, but its average surface

temperate is 470ºC making
it the hottest planet in the
solar system. Its surface
is manly rocky and hard
with numerous volcanoes
all over the planet. Venus
is the hottest planet in
the solar system because
its thick atmosphere and
green house gases traps
huge amounts of heat from
the Sun. The Babylonians
were the rst to record
observations of the planet
over 3,600 years ago.
2
Venus
Diameter: 12,756 km
Distance to Sun:
149,600,000 km (1 AU)
Orbital Period: 365 Days
Surface Area:
510,000,000 km2
Number of Moons: 1
Axial Tilt: 23.4º
Earth, the third planet
from the Sun and the only
planet in this solar system
that can support life. Earth
is also the largest of the

terrestrial or inner planets,
which comprises of Mercu-
ry, Venus, Earth and Mars.
The continents on Earth
have been formed by mil-
lions of years of plate tec-
tonic movements on the
Earths crust.
The unit AU or Astronomi-
cal Unit comes from the
average distance between
the Earth and the Sun; it
has become a standard
unit when measuring the
distance from a planet to
the Sun. The time it takes
for one planetary rotation
on its axis is about 23.93
Earth hours. Alternate
names for Earth are Terra
or Gaia, but the name Earth
comes from Old English
name Eorthe. The atmos-
phere mainly comprises of
nitrogen and oxygen along
with other traces of carbon
dioxide, some water vapor
and other gases.
The atmosphere also pro-
tects the surface of the

planet by shielding harmful
UV rays from the Sun. More
than three quarters of the
Earths surface is covered
with water, which include
rivers, lakes, seas, oceans,
glaciers, and ice caps. The
lowest temperature ever
recorded on Earth is –89ºC
and the highest is 58ºC,
with an average tempera-
ture of 22ºC. The surface
ranges from tall moun-
tains to deep valleys, but
mainly covered with wa-
ter. Over 3,000 years ago
early Greek philosophers
thought that Earth was a
at dish. Earth has only
one moon called Luna, and
its pull of gravity is what
causes the rise and fall of
the oceans called tides.
3
Earth
Diameter: 6,780 km
Distance to Sun:
227,940,000 km (1.52 AU)
Orbital Period:
687 Earth Days

Surface Area:
144,000,000 km2
Number of Moons: 2
Axial Tilt: 25.2º
The forth planet from the
Sun, Mars is the last plan-
et before the main aster-
oid belt separating the in-
ner terrestrial planets from
the Gas Giants. The sur-
face of Mars has been very
well documented and huge
maps of the planet have
been made. The axial rota-
tion of the planet is 24.62
Earth hours, being very
similar to that of Earth, but
one orbit around the Sun
would take almost twice
as long when compared to
Earth. The name Mars also
comes from the Roman god
of war, but it is also some-
times called the Red Plan-
et because of the reddish
orange hue of the planet.
The planet is bright enough
to be seen with the naked
eye on a clear night sky.
The atmosphere is mainly

comprised of carbon diox-
ide with small amounts of
nitrogen and argon, with
small traces of oxygen and
carbon monoxide and wa-
ter vapor.
The surface is comprised
of mainly Iron Oxide in
the form of dust and rock
as well as many big vol-
canoes, deep valleys, and
large plains. Water in the
form of ice can be found on
the north polar ice cap of
Mars, features resembling
riverbeds, estuaries and
shorelines have led scien-
tist to speculate whether
life ever existed on Mars.
Many space probes, landers
and rovers were sent to
Mars but none of them
reported any signs of life
on the planet. Over 4,000
years ago ancient Egyptian
astronomers were the rst
to observe Mars.
4
Mars
Diameter: 142,984 km

Distance to Sun:
778,330,000 km (5.20 AU)
Orbital Period: 4,333 Earth
Days (11.8 Earth Years)
Surface Area:
61,400,000,000 km2
Number of Moons: 60+
Axial Tilt: 3.13º
The fth planet from the
Sun and the rst of the
outer planets, Jupiter is the
largest planet in the so-
lar system. The four outer
planets such as Jupiter are
known as Gas Giants be-
cause they are not mainly
comprised of solid matter.
Jupiter has one of the fast-
est axial rotation period as
it just takes the planet only
9.92 hours to make one ro-
tation on its axis. Jupiter
is the third brightest ob-
ject in the night sky after
the Moon and Venus. The
name of Jupiter yet again
comes from Roman mythol-
ogy, this time from the Ro-
man king of the gods, and
is also sometimes called

Jove. The atmosphere is
mostly of hydrogen, hydro-
gen sulde and some he-
lium along traces of meth-
ane, water vapor, ammonia
and other gases. Due to its
huge gravitational pull Ju-
piter has over 60 known
natural satellites that orbit
around it.
Jupiter like the other gas
giants is a very cold planet
with the lowest tempera-
ture being –170ºC and
the highest temperature
being –110ºC, but has an
average temperature of
–163ºC. Jupiter has a small
molten core although there
is no clear surface that can
be seen as it is surround-
ed by many different lay-
ers of metallic, liquid, and
gaseous hydrogen as well
as other gases. Jupiter is
in fact so heavy that it is
twice as heavy than all the
other planets put togeth-
er, but is still only 1/1000
the mass of the Sun. Jupi-

ter was rst known to the
Greeks then the Romans
over 3,000 years ago.
Jupiter
5
Diameter: 120,536 km
Distance to Sun:
1,420,400,000 km (9.54
AU)
Orbital Period: 10,759
Earth Days (29.5 Earth
Years)
Surface Area:
42,700,000,000 km2
Number of Moons: 50+
Axial Tilt: 26.7º
Saturn the sixth planet
from the Sun is the sec-
ond largest planet in the
solar system. The density
of the planet is the lowest
in the solar system; in fact
it is so low that it is lower
than the density of water.
One whole axial rotation is
approximately 10.77 Earth
hours making it the second
fastest behind Jupiter. Sat-
urn can usually be seen in
the night sky but it is not

nearly as bright as the oth-
er planets closer to Earth.
The name comes from the
Roman god of farming,
civilization, and prosperity.
Its atmosphere much like
that of Jupiter comprises of
mainly hydrogen and small
amounts of helium as well
as trace elements of meth-
ane, water vapor, and am-
monia. The most distinc-
tive quality of Saturn is
its rings that surround the
planet in its equator, these
rings are made of billions of
ice and rock particles that
reect sunlight to sparkle.
The surface temperatures,
much like Jupiter are very
cold with the lowest tem-
perature being –190ºC and
the highest being –120ºC,
with an average tempera-
ture of –130ºC. It does
have a solid molten core
at a depth of 52,300 km
below the surface that is
surrounded by layers of
metallic and molecular hy-

drogen much like Jupiter.
Due to its light density and
fast speed the planet has a
bulge in the equator, so it
is wider than it is tall. Over
2,500 years ago the Greeks
and then the Romans had
rst known and document-
ed the planet Saturn.
6
Saturn
Diameter: 51,118 km
Distance to Sun:
2,870,990,000 km (19.22
AU)
Orbital Period: 30,799
Earth Days (84.1 Earth
Years)
Surface Area:
8,080,000,000 km2
Number of Moons: 30+
Axial Tilt: 97.8º
The seventh planet from
the Sun, Uranus is the third
gas giant and also the sec-
ond last planet it the solar
system. It is more speci-
cally known as an ice gi-
ant and is sometimes pro-
nounced as yur-in-as. Its

axial rotation is 17.2 Earth
hours. Uranus is the one
of two planets that cannot
be seen by the naked eye,
and have been discovered
by the use of telescopes.
The name for Uranus does
not come from the Romans
but in fact comes from the
Greek god of the heavens,
had the name come from
the Romans it would have
been called ‘Caelus’. Its at-
mosphere is quite similar
to that of Jupiter and Sat-
urn as it mainly contains
hydrogen as well as some
helium and methane with
traces of ammonia. The tilt
of axis is almost at right
angles to the Sun so that it
seems like the entire plan-
et is on its side.
Its surface temperature is
colder than both Jupiter
and Saturn with the lowest
temperature being –214ºC
and the highest tempera-
ture being –200ºC, it has
an average temperature

of –205ºC. Its surface is
very gassy with solid sur-
faces deep below the at-
mosphere, which contains
mainly rock and ice. The
mass of Uranus is more
than 27 times that of the
mass of Earth. Uranus and
Neptune were the only
two planets that were not
know to ancient civilization
due to its great distance.
The rst record of Uranus
was a dim star-like object
in 1660 but it was in 1781
when it was rst identied
as a planet.
7
Uranus
Diameter: 49,528 km
Distance to Sun:
4,504,000,000 km (30.06
AU)
Orbital Period: 60,190
Earth Days (164.8 Earth
Years)
Surface Area:
7,620,000,000 km2
Number of Moons: 13
Axial Tilt: 28.3º

The eighth planet, Nep-
tune is the furthest and
last planet in our solar
system it is also the sec-
ond ice giant. Neptune is
also the coldest planet in
the solar system being so
far away from the Sun. Its
lowest temperature goes
down to –223ºC and the
highest being –218ºC but
has an average of –218ºC.
Its axial rotation is about
16.1 hours making it slow-
er than that of Uranus but
its orbit around the Sun is
double that of Uranus. Nep-
tune also cannot be seen
with the naked eye and a
telescope is needed to see
the planet with its distinc-
tive characteristics. The
name comes from the Ro-
man god of the sea partly
due to the distinctive dark
blue hue of the planet. Its
atmosphere is again most-
ly hydrogen with some he-
lium and traces of methane
and ethane. The fastest

winds in the solar system
occur in the atmosphere
of the planet. Its surface
is mainly rocks, methane,
ammonia, and semi-liquid
ice with the core being
mainly of molten rocks and
metals. The dark blue color
of the planet comes from
the huge quantity of meth-
ane in the atmosphere that
traps all red light and only
reects blue light from the
Sun. Neptune is the other
planet that has been dis-
covered by the use of tele-
scopes rst in 1612 by Gal-
ileo but ofcially recorded
as a planet in 1846 by Jo-
hann Galle. The planet be-
ing so far away from the
Sun has little to no effect
from the heat and light.
8
Neptune
“Dead Space Box Art.” DaFonts. N.p., n.d. Web. 17 Dec. 2012.
< />“Kuler.” Kuler. Adobe, n.d. Web. 17 Dec. 2012.
< />“Matt Jay Mug Blog: Dad’s Wise Words.” Jay Mug â Mattjayblog: Dad’s
Wise Words. Applicable to Any N.p., n.d. Web. 17 Dec. 2012.
< /> wise-words-applicable-to-any>.

“Nine Planets.” The Solar System Tour. N.p., n.d. Web. 17 Dec. 2012.
< />“Our Solar System: Facts, Formation and Discovery.” Space.com. N.p.,
n.d. Web. 17 Dec. 2012.
< /> discovery.html>.
“Solar System Exploration: Multimedia: Gallery: Planetary Images.” Solar
System Exploration: Multimedia: Gallery: Planetary Images. NASA,
n.d. Web. 17 Dec. 2012.
< />“Solar System.” National Geographic. National Geography, n.d. Web. 17
Dec. 2012. < /> solar-system/>.
“Xenotron.” DaFonts. N.p., n.d. Web. 17 Dec. 2012.
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