solar system

1. NAME: HIMANSHUNAME: HIMANSHU
AGGARWALAGGARWAL
CLASS: VIIIthCLASS: VIIIth
ROLL NO: 10ROLL NO: 10
NORTH EX PUBLIC SCHOOLNORTH EX PUBLIC SCHOOL

2. SOLAR
SYSTEM

3. The Solar System[a]
consists of the Sun and the
astronomical objects bound to it by gravity, all of which formed
from the collapse of a giant molecular cloud approximately 4.6
billion years ago. Of the many objects that orbit the Sun, most
of the mass is contained within eight relatively solitary planets[e]
whose orbits are almost circular and lie within a nearly flat disc
called the ecliptic plane. The four smaller inner planets,
Mercury, Venus, Earth and Mars, also called the
terrestrial planets, are primarily composed of rock and metal.
The four outer planets, the gas giants, are substantially more
massive than the terrestrials. The two largest, Jupiter and
Saturn, are composed mainly of hydrogen and helium; the two
outermost planets, Uranus and Neptune, are composed largely
of ices, such as water, ammonia and methane, and are often
referred to separately as "ice giants".
SOLAR SYSTEM DEFINTION

4. Discovery and explorationDiscovery and exploration
many thousands of years, humanity, with a few notable exceptions, did notmany thousands of years, humanity, with a few notable exceptions, did not
recognize the existence of the Solar System. People believed the Earth to berecognize the existence of the Solar System. People believed the Earth to be
stationary at the center of the stationary at the center of the universeuniverse and categorically different from the and categorically different from the
divine or ethereal objects that moved through the sky. Although the divine or ethereal objects that moved through the sky. Although the GreekGreek
philosopher philosopher Aristarchus of SamosAristarchus of Samos had speculated on a heliocentric reordering had speculated on a heliocentric reordering
of the cosmos,of the cosmos,[1][1]
Nicolaus CopernicusNicolaus Copernicus was the first to develop a mathematically was the first to develop a mathematically
predictive predictive heliocentricheliocentric system. system.[2][2]
His 17th-century successors, His 17th-century successors, Galileo GalileiGalileo Galilei,,
Johannes KeplerJohannes Kepler and and Isaac NewtonIsaac Newton, developed an understanding of , developed an understanding of physicsphysics
that led to the gradual acceptance of the idea that the Earth moves around the that led to the gradual acceptance of the idea that the Earth moves around the
Sun and that the planets are governed by the same physical laws that governedSun and that the planets are governed by the same physical laws that governed
the Earth. In more recent times, improvements in the telescope and the use of the Earth. In more recent times, improvements in the telescope and the use of
unmanned spacecraftunmanned spacecraft have enabled the investigation of geological phenomena have enabled the investigation of geological phenomena
such as such as mountainsmountains and and craterscraters, and seasonal meteorological phenomena such, and seasonal meteorological phenomena such
as as cloudsclouds, , dust stormsdust storms and and ice capsice caps on the other planets. on the other planets.

5. STRUCTURESTRUCTURE

6. The principal component of the Solar System is the Sun,
a main sequence G2 star that contains 99.86 percent of
the system's known mass and dominates it
gravitationally.[3]
The Sun's four largest orbiting bodies,
the gas giants, account for 99 percent of the remaining
mass, with Jupiter and Saturn together comprising more
than 90 percent.[c]
Most large objects in orbit around the Sun lie near the
plane of Earth's orbit, known as the ecliptic. The planets
are very close to the ecliptic while comets and Kuiper belt
objects are frequently at significantly greater angles to it.
[4][5]
All the planets and most other objects orbit the Sun in
the same direction that the Sun is rotating (counter-
clockwise, as viewed from above the Sun's north pole).
For exceptions, seeretrograde motion.

7. SUNSUN
• The Sun is the Solar System's The Sun is the Solar System's starstar, and by far its chief component. Its, and by far its chief component. Its
large mass (332,900 Earth masses)large mass (332,900 Earth masses)[13][13]
produces temperatures and produces temperatures and
densities in its densities in its corecore great enough to sustain great enough to sustain nuclear fusionnuclear fusion,,[14][14]
which which
releases enormous amounts of releases enormous amounts of energyenergy, mostly , mostly radiatedradiated into into spacespace as as
electromagnetic radiationelectromagnetic radiation, peaking in the 400–700 nm band we call , peaking in the 400–700 nm band we call
visible lightvisible light..[15][15]
• The Sun is classified as a type G2 The Sun is classified as a type G2 yellow dwarfyellow dwarf, but this name is, but this name is
misleading as, compared to the majority of stars in misleading as, compared to the majority of stars in our galaxyour galaxy, the, the
Sun is rather large and bright.Sun is rather large and bright.[16][16]
Stars are classified by the Stars are classified by the
Hertzsprung–Russell diagramHertzsprung–Russell diagram, a graph that plots the brightness of, a graph that plots the brightness of
stars with their surfacestars with their surfacetemperaturestemperatures. Generally, hotter stars are. Generally, hotter stars are
brighter. Stars following this pattern are said to be on the brighter. Stars following this pattern are said to be on the
main sequencemain sequence, and the Sun lies right in the middle of it. However,, and the Sun lies right in the middle of it. However,
stars brighter and hotter than the Sun are rare, while substantiallystars brighter and hotter than the Sun are rare, while substantially
dimmer and cooler stars, known as dimmer and cooler stars, known as red dwarfsred dwarfs, are common, making, are common, making
up 85 percent of the stars in the galaxy.up 85 percent of the stars in the galaxy.[16][16][17][17]

8. Inner Solar SystemInner Solar System
The inner Solar System is theThe inner Solar System is the
traditional name for the regiontraditional name for the region
comprising the terrestrial planetscomprising the terrestrial planets
and asteroids.and asteroids.[31][31]
Composed mainlyComposed mainly
ofof silicatessilicates and metals, the objectsand metals, the objects
of the inner Solar System areof the inner Solar System are
relatively close to the Sun; therelatively close to the Sun; the
radius of this entire region isradius of this entire region is
shorter than the distance betweenshorter than the distance between
Jupiter and Saturn.Jupiter and Saturn.

9. INNER
PLANETS
• The four inner or terrestrial
planets have dense, rocky
compositions, few or no moons,
and no ring systems. They are
composed largely ofrefractory
minerals, such as the silicates,
which form their crusts and
mantles, and metals such as
iron and nickel, which form
their cores. Three of the four
inner planets (Venus, Earth and
Mars) have atmospheres
substantial enough to generate
weather; all have impact craters
and tectonic surface features
such as rift valleys and
volcanoes. The term inner
planet should not be confused
with inferior planet, which
designates those planets that
are closer to the Sun than Earth
is (i.e. Mercury and Venus).
•

10. Mercury (0.4 AU from the Sun) is the closest planet to the
Sun and the smallest planet in the Solar System (0.055
Earth masses). Mercury has no natural satellites, and its
only known geological features besides impact craters
are lobed ridges or rupes, probably produced by a period
of contraction early in its history.[32]
Mercury's almost
negligible atmosphere consists of atoms blasted off its
surface by the solar wind.[33]
Its relatively large iron core
and thin mantle have not yet been adequately explained.
Hypotheses include that its outer layers were stripped off
by a giant impact, and that it was prevented from fully
accreting by the young Sun's energy.[34][35]
MercuryMercury

11. Venus
• Venus (0.7 AU from the Sun) is close in size to
Earth (0.815 Earth masses), and, like Earth, has a
thick silicate mantle around an iron core, a
substantial atmosphere and evidence of internal
geological activity. However, it is much drier than
Earth and its atmosphere is ninety times as dense.
Venus has no natural satellites. It is the hottest
planet, with surface temperatures over 400 °C,
most likely due to the amount of greenhouse gases
in the atmosphere.[36]
No definitive evidence of
current geological activity has been detected on
Venus, but it has no magnetic field that would
prevent depletion of its substantial atmosphere,
which suggests that its atmosphere is regularly
replenished by volcanic eruptions.[3

12. EarthEarth
• EarthEarth (1 AU from the Sun) is the largest and (1 AU from the Sun) is the largest and
densest of the inner planets, the only onedensest of the inner planets, the only one
known to have current geological activity, andknown to have current geological activity, and
is the only place in the is the only place in the universeuniverse where where lifelife is is
known to exist.known to exist.[38][38]
Its liquid Its liquid hydrospherehydrosphere is is
unique among the terrestrial planets, and it isunique among the terrestrial planets, and it is
also the only planet where also the only planet where plate tectonicsplate tectonics has has
been observed. Earth's atmosphere isbeen observed. Earth's atmosphere is
radically different from those of the otherradically different from those of the other
planets, having been altered by the presenceplanets, having been altered by the presence
of life to contain 21% free of life to contain 21% free oxygenoxygen..[39][39]
It has one It has one
natural satellite, the Moon, the only largenatural satellite, the Moon, the only large
satellite of a terrestrial planet in the Solarsatellite of a terrestrial planet in the Solar
System.System.

13. Outer Solar SystemOuter Solar System
The outer region of the Solar System isThe outer region of the Solar System is
home to the gas giants and their largehome to the gas giants and their large
moons. Many short period comets,moons. Many short period comets,
including the centaurs, also orbit in thisincluding the centaurs, also orbit in this
region. Due to their greater distanceregion. Due to their greater distance
from the Sun, the solid objects in thefrom the Sun, the solid objects in the
outer Solar System contain a higherouter Solar System contain a higher
proportion of volatiles such as water,proportion of volatiles such as water,
ammonia and methane, than the rockyammonia and methane, than the rocky
denizens of the inner Solar System, asdenizens of the inner Solar System, as
the colder temperatures allow thesethe colder temperatures allow these
compounds to remain solid.compounds to remain solid.

14. OUTER PLANETSOUTER PLANETS
The four outer planets, or gas giants (sometimes called
Jovian planets), collectively make up 99 percent of the
mass known to orbit the Sun.[c] Jupiter and Saturn
are each many tens of times the mass of the Earth
and consist overwhelmingly of hydrogen and helium;
Uranus and Neptune are far less massive (<20 Earth
masses) and possess more ices in their makeup. For
these reasons, some astronomers suggest they
belong in their own category, “ice giants.”[54] All four
gas giants have rings, although only Saturn's ring
system is easily observed from Earth. The term outer
planet should not be confused with superior planet,
which designates planets outside Earth's orbit and
thus includes both the outer planets and Mars.