The Solar system, Stars The Solar system, Stars and Galaxyand Galaxy

Chapters 24 & 25Chapters 24 & 25

The solar systemThe solar system

People originally thought the Earth was the People originally thought the Earth was the center of the solar system until Copernicus center of the solar system until Copernicus proved that the sun was the center and the earth proved that the sun was the center and the earth revolved around it.revolved around it.

The solar system is made of nine planets that all The solar system is made of nine planets that all orbit the sun. orbit the sun.

These planets are pulled to the sun b/c it has These planets are pulled to the sun b/c it has immense gravitational pull due to the fact that it immense gravitational pull due to the fact that it is 99.86% of the solar systems total mass. is 99.86% of the solar systems total mass.

Scientists believe that the solar system was Scientists believe that the solar system was formed when a cloud of gas and dust in space formed when a cloud of gas and dust in space was disturbed, maybe by the explosion of a was disturbed, maybe by the explosion of a nearby star (called a supernova). nearby star (called a supernova).

This explosion made waves in space which This explosion made waves in space which squeezed the cloud of gas and dust. Squeezing squeezed the cloud of gas and dust. Squeezing made the cloud start to collapse, as gravity made the cloud start to collapse, as gravity pulled the gas and dust together, forming a pulled the gas and dust together, forming a solar nebula,solar nebula, the cloud began to spin as it the cloud began to spin as it collapsed. .collapsed. .

As the disk got thinner and thinner, particles As the disk got thinner and thinner, particles began to stick together and form clumps. Some began to stick together and form clumps. Some clumps got bigger, as particles and small clumps clumps got bigger, as particles and small clumps stuck to them, eventually forming planets or stuck to them, eventually forming planets or moon. moon.

Planet MotionPlanet Motion The planets do The planets do

not revolve not revolve around the sun in around the sun in a circle, the orbit a circle, the orbit in eclipses.in eclipses.

Planets closest to Planets closest to the sun orbit the the sun orbit the sun faster than sun faster than those further those further away.away.

H.W. pg 695H.W. pg 695

ques. 1-4ques. 1-4

The inner planetsThe inner planetsThey are: Mercury, Venus, Earth , and They are: Mercury, Venus, Earth , and

Mars.Mars.Mercury- is the planet closest to our Sun, Mercury- is the planet closest to our Sun,

and it is the eighth largest of the nine and it is the eighth largest of the nine planets.planets.

Mercury is a small, rocky planet - much Mercury is a small, rocky planet - much like our Moon. It is covered with craters like our Moon. It is covered with craters and has changed very little from when it and has changed very little from when it was first formed. was first formed.

One of Mercury's largest features is called One of Mercury's largest features is called the the Caloris BasinCaloris Basin. It is about 1300 km . It is about 1300 km across.across.

The inner planetsThe inner planets

Venus- is the second planet from the Sun, Venus- is the second planet from the Sun, and the sixth largest of all the nine planets.and the sixth largest of all the nine planets.

Venus probably once had large amounts Venus probably once had large amounts of water like Earth, but it all boiled away. of water like Earth, but it all boiled away. The same thing would have happened to The same thing would have happened to the Earth had it been just a little closer to the Earth had it been just a little closer to the Sun. Because Venus is so similar to the Sun. Because Venus is so similar to our Earth, we sometimes call it Earth's our Earth, we sometimes call it Earth's "sister planet." "sister planet."

The inner planetsThe inner planets

Earth is the third planet from the Sun, and Earth is the third planet from the Sun, and the fifth largest of the nine planets. the fifth largest of the nine planets.

The Earth's surface is very The Earth's surface is very youngyoung. This . This means that the Earth's surface has means that the Earth's surface has changed a lot from when it was first changed a lot from when it was first formed. Erosion and tectonic processes formed. Erosion and tectonic processes (like earthquakes) destroy, recreate and (like earthquakes) destroy, recreate and reshape most of the Earth's surface. reshape most of the Earth's surface.

The inner planetsThe inner planets

Mars is the fourth planet from the Sun, and Mars is the fourth planet from the Sun, and the seventh largest of the nine planets.the seventh largest of the nine planets.

Olympus Mons - The largest mountain in Olympus Mons - The largest mountain in the Solar System! Olympus Mons rises a the Solar System! Olympus Mons rises a full 24 km (78,000 ft.) above the full 24 km (78,000 ft.) above the surrounding plain. surrounding plain.

It has a thinner atmosphere tan earth and It has a thinner atmosphere tan earth and has temps that range from 35-125 C.has temps that range from 35-125 C.

H.W. pg 701 ques 1-4.H.W. pg 701 ques 1-4.

The Outer PlanetsThe Outer Planets Include Jupiter, Saturn, Uranus, Neptune, and Include Jupiter, Saturn, Uranus, Neptune, and

Pluto.Pluto. Jupiter is the fifth planet from the Sun and by far Jupiter is the fifth planet from the Sun and by far

the largest of all nine planets. Jupiter is more the largest of all nine planets. Jupiter is more than twice as massive as all the other planets than twice as massive as all the other planets combined - It's 318 times bigger than the Earth!combined - It's 318 times bigger than the Earth!

The swirls and bands we see when looking at The swirls and bands we see when looking at Jupiter are the tops of clouds high in its Jupiter are the tops of clouds high in its atmosphere.atmosphere.

The Great Red Spot is a high-pressure region The Great Red Spot is a high-pressure region whose cloud tops are much higher and colder whose cloud tops are much higher and colder than the surrounding areas. than the surrounding areas.

The Outer PlanetsThe Outer Planets

Saturn is the sixth planet from the Sun, Saturn is the sixth planet from the Sun, and the second largest of the nine planets.and the second largest of the nine planets.

Saturn's rings, unlike the rings of the Saturn's rings, unlike the rings of the other gas planets, are very bright. Though other gas planets, are very bright. Though they look "solid" or continuous from the they look "solid" or continuous from the Earth, the rings are actually composed of Earth, the rings are actually composed of many, many small particles circling Saturn many, many small particles circling Saturn at their own speeds. at their own speeds.

The Outer PlanetsThe Outer Planets

Uranus is the seventh planet from the Sun Uranus is the seventh planet from the Sun and the third largest of the nine planets. and the third largest of the nine planets.

Uranus' blue color is the result of a gas Uranus' blue color is the result of a gas called "methane" found in the planet's called "methane" found in the planet's upper atmosphere. Uranus may have upper atmosphere. Uranus may have colored bands like Jupiter's, but they are colored bands like Jupiter's, but they are hidden from view by the overlaying hidden from view by the overlaying methane layer.    methane layer.   

The Outer PlanetsThe Outer Planets

Neptune is the eighth planet from the Sun Neptune is the eighth planet from the Sun and the fourth largest of the nine planets.and the fourth largest of the nine planets.

Neptune has rapid winds trapped in Neptune has rapid winds trapped in "bands" of large storms. Neptune's winds "bands" of large storms. Neptune's winds are the fastest in the solar system, are the fastest in the solar system, reaching 2000 km/hour.reaching 2000 km/hour.

The Outer PlanetsThe Outer Planets

Pluto is the farthest planet from the Sun Pluto is the farthest planet from the Sun and by far the smallest of the nine planets.and by far the smallest of the nine planets.

To date, not much is known about the To date, not much is known about the planet, Pluto. planet, Pluto.

Pluto is so far away that even the Hubble Pluto is so far away that even the Hubble Space Telescope can make out only the Space Telescope can make out only the largest features on its surface. largest features on its surface.

Has a moon called CharonHas a moon called Charon

Other objects in the solar systemOther objects in the solar systemH.W. pg 720 ques. 1-15H.W. pg 720 ques. 1-15

Comets- are dust and rock particles mixed with Comets- are dust and rock particles mixed with frozen water, methane, and ammonia.frozen water, methane, and ammonia.

Halley’s Comet was discovered by Edmund Halley’s Comet was discovered by Edmund Halley and it is seen every 75-76 years.Halley and it is seen every 75-76 years.

Hale-Bopp comet- is the brightest comets man Hale-Bopp comet- is the brightest comets man has seen. It was able to be seen in space for 18 has seen. It was able to be seen in space for 18 months.months.

A meteoroid- pieces of broken comets, when it A meteoroid- pieces of broken comets, when it burns up and enters Earth’s atmosphere it is burns up and enters Earth’s atmosphere it is than called a meteor, if it hits earth than it’s a than called a meteor, if it hits earth than it’s a meteorite. meteorite.

Asteroids are pieces of rock similar to the ones Asteroids are pieces of rock similar to the ones that formed planets. They lie between orbits of that formed planets. They lie between orbits of planets.planets.