Solar System

Brought to you by:

Taha Mehmood

Agenda

• Solar System• Theories of Solar System• Classification of Solar System• Sun• Planets• Movement of Planets• Size of Planets

Solar System

• The term ‘solar system’ takes its name from the object at the centre of it all—the Sun, also known as Sol

• For thousands of years ancient astronomers saw points of light that appeared to move among the stars

• They called these, as ‘planets’-meaning ‘wanderers’

• Named them on the Roman gods• You might see an assortment of space junk and

satellites that also move in the night sky

Solar System contd

• It includes: the satellites of the planets; numerous comets, asteroids, and meteoroids; and the interplanetary medium

• The inner solar system contains the Sun, Mercury, Venus, Earth and Mars

• The planets of the outer solar system are Jupiter, Saturn, Uranus, and Neptune (Pluto is now classified as a dwarf planet)

• The planets orbit the Sun in or near the same plane, called the ecliptic

Inner Solar System

Outer Solar System

Composition Of The Solar System

• The Sun contains 99.85% of all the matter in the Solar System

• The planets, which condensed out of the same disk of material that formed the Sun, contain only 0.135% of the mass of the solar system

• Jupiter contains more than twice the matter of all the other planets combined

• Satellites of the planets, comets, asteroids, meteoroids, and the interplanetary medium constitute the remaining 0.015%.

• The following table is a list of the mass distribution within our Solar System.– Sun: 99.85%– Planets: 0.135%– Comets: 0.01%– Satellites: 0.00005%– Minor Planets: 0.0000002%– Meteoroids: 0.0000001%– Interplanetary Medium: 0.0000001%

Theories of Solar System

• Pythagoras a Greek scientist who lived in the sixth century BC suggested that the Earth was the centre of the universe

• Aristotle, Hipparchus and Ptolemy proposed more detailed models in which Earth was placed at the centre of the solar system

• This type of model is known as the geocentric (geo-earth).

Geocentric Model

• Another ancient Greek, Aristarchus questioned the geocentric model and proposed a model where the Earth and other planets revolved around the Sun

• This is known as a heliocentric model – Helio = Sun

• The geocentric model continued to be favoured until the end of the fifteenth century

• In the 1530s, Polish astronomer Nicolas Copernicus (1473–1543) agreed with Aristarchus

Heliocentric Model

Classification of Solar SystemThe eight bodies officially categorized as planets

are often further classified in several ways:• By composition:

– terrestrial or rocky planets: Mercury, Venus, Earth, and Mars:

– The terrestrial planets are composed primarily of rock and metal and have relatively high densities, slow rotation, solid surfaces, no rings and few satellites.

– Jovian or gas planets: Jupiter, Saturn, Uranus, and Neptune:

– The gas planets are composed primarily of hydrogen and helium and generally have low densities, rapid rotation, deep atmospheres, rings and lots of satellites.

• By position relative to Earth:– Inferior planets: Mercury and Venus.

• closer to the Sun than Earth.• The inferior planets show phases like the Moon's

when viewed from Earth.• Earth.

– Superior planets: Mars thru Neptune.• farther from the Sun than Earth.• The superior planets always appear full or nearly

so.

• By position relative to the Sun:– inner planets: Mercury, Venus, Earth and

Mars.– outer planets: Jupiter, Saturn, Uranus,

Neptune– The asteroid belt between Mars and Jupiter

forms the boundary between the inner solar system and the outer solar system.

• By size:– small planets: Mercury, Venus, Earth, Mars.– The small planets have diameters less than

13000 km. – giant planets: Jupiter, Saturn, Uranus and

Neptune.– The giant planets have diameters greater than

48000 km. – The giant planets are sometimes also referred

to as gas giants.

• By history:

– classical planets: Mercury, Venus, Mars, Jupiter, and Saturn.• Known since prehistorical times• Visible to the unaided eye

– modern planets: Uranus, Neptune.• Discovered in modern times• Visible only with optical aid

SunMankind will not remain on Earth forever, but in its quest for light and space will at first timidly penetrate beyond the confines of the atmosphere, and later will conquer for itself all the space near the Sun. - Konstantin E. Tsiolkovsky

• The Sun is the most prominent feature in our solar system

• It is the largest object and contains approximately 98% of the total solar system mass

• The Sun appears to have been active for 4.6 billion years and has enough fuel to go on for another five billion years or so

• The Sun's outer visible layer is called the photosphere and has a temperature of 6,000°C (11,000°F).

• The diameter is 109 times the diameter of Earth.

• Solar energy is created deep within the core of the Sun.

• Energy generated in the Sun's core takes a million years to reach its surface.

• The chromosphere is above the photosphere. Solar energy passes through this region on its way out from the center of the Sun.

• The corona is the outer part of the Sun's atmosphere

Planets

Mercury

When men are arrived at the goal, they should not turn back. - Plutarch

• Mercury was named by the Romans after the fleet-footed messenger of the gods because it seemed to move more quickly than any other planet.

• It is the closest planet to the Sun, and second smallest planet in the solar system.

• Its diameter is 40% smaller than Earth and 40% larger than the Moon.

• It is even smaller than Jupiter's moon Ganymede and Saturn's moon Titan.

• A small, rocky planet that looks like our moon.

• Covered with millions of craters.

• No moons

Venus

• Advance in science comes by laying brick upon brick, not by sudden erection of fairy palaces.- J. S. Huxley

• Venus, the jewel of the sky, was once known by ancient astronomers as the morning star and evening star.

• It is named after the Roman goddess of love and beauty

• Venus is veiled by thick swirling cloud cover.

• Astronomers refer Venus to as Earth's sister planet.

• Both are similar in size, mass, density and volume.

• Both formed about the same time

• The hottest planet.• Has the longest day.• Spins in the opposite direction

of the other planets.• The clouds and rain are filled

with sulfuric acid.• No moons.

Earth

• My view of our planet was a glimpse of divinity. -Edgar Mitchell, USA

• The only planet to have liquid water on the surface.

• Earth is the only planet in the solar system known to harbor life.

• It takes 365.256 days to travel around the Sun and 23.9345 hours for the Earth rotate a complete revolution.

• It has a diameter of 12,756 kilometers, only a few hundred kilometers larger than that of Venus.

• Surrounded by a thick atmosphere of gases.

• One moon.

Mars

• Commonly referred to as the Red Planet

• The surface is covered with iron; giving it a red color.

• Has the highest mountain in the solar system.

• It was given its name by the Romans in honor of their god of war.

• The atmosphere of Mars is quite different from that of Earth.

• It is composed primarily of carbon dioxide with small amounts of other gases

• The polar caps have layers of ice covering them.

• Two moons.– Phobos– Deimos

Jupiter

• The largest planet.• If Jupiter were hollow, more

than one thousand Earths could fit inside.

• It also contains more matter than all of the other planets combined.

• The shortest day.• Famous for its giant red spot

which is a large storm.• Jupiter possesses 28 known

satellites• One ring

– It is very faint – Totally invisible from the

Earth

Saturn

• It is the second largest in the solar system.

• Diameter of 119,300 kilometers.

• Its day is 10 hours, 39 minutes long.

• it takes 29.5 Earth years to revolve about the Sun.

• A large gas giant with beautiful rings.

• Saturn's ring system makes the planet one of the most beautiful objects in the solar system.

• Saturn has 30 named satellites and more continue to be discovered.

• It is extremely large but so light it could float in water.

Uranus

• Diameter of 51,800 kilometers.

• Orbits the Sun once every 84.01 Earth years.

• large gas giant tipped over on its side.

• A beautiful, featureless blue planet.

• Has a small hot rocky center and an ice surface.

• At least 11 rings.• At least 15 moons.

Neptune

• A large gas giant, the twin of Uranus.

• Diameter of 49,500 Km• Neptune orbits the Sun

every 165 years.• A day on Neptune is 16

hours and 6.7 minutes.• It has eight moons.• Long bright clouds,

similar to clouds on Earth, were seen high in Neptune's atmosphere

Pluto is a Planet..Sure..?

• Pluto loosed its status as a planet• Because:

– Pluto failed to dominate its orbit around the Sun in the same way as the other planets.

• The scientists agreed that for a celestial body to qualify as a planet:– it must be in orbit around the Sun – it must be large enough that it takes on a nearly round shape– it has cleared its orbit of other objects

• Pluto was automatically disqualified because its highly elliptical orbit overlaps with that of Neptune. It will now join a new category of dwarf planets.

Movement of Planet

• The four innermost planets are called terrestrial (meaning ‘Earth-like’) and orbit the Sun in almost circular orbits

• The larger outer planets—Jupiter, Saturn, Uranus and Neptune—are known as the gas giants (or Jovian planets), because their outer layers are composed of gases such as hydrogen and helium, and they move in elliptical or oval orbits

• All planets move in the same plane (a large imaginary flat surface) except for Pluto, whose orbit is tilted by about 17° compared to the other planets’ orbits.

The terrestrial planets

http://solarsystem.nasa.gov/multimedia/gallery/terr_sizes.jpg

The gas giants

Comparing tilt of axisMovement of Planet

How small Earth is?

Earth

Compare the size of the earth with other planets

Now compare it with Uranus & Neptune

This is the Earth

Now Earth against Sun

Against Sun, Earth is like a dot Think !! Where do you find yourself now?? This is

the Earth

Thanks for Attention..