The Earth in Space`- The Earth in Space

The Solar System Our solar system consists of nine planets ( now eight) Earth is the third planet from the sun

Solar System Every planet travels on a path known as their ORBIT. An orbit is a elliptical shape (stretched out circle) Every planet takes a different amount of time to complete their orbit Earth takes 365 ¼ days to go around the sun once.

The Planets Earth like Planets Mercury Venus Mars Pluto Solid Small No or few moons Spin slowly Jupiter like Planets Jupiter Saturn Neptune Uranus Balls of gas Spin rapidly Many moons Surrounding rings

The Sun 93 million miles away from earth Made of hot gases Temperature – 27 million degrees Fahrenheit The sun gives off the light and warmth without it life would not exist.

The Sun and the Seasons The earth is tilted on an angle of 23 ½ degrees on its axis Due to this tilt we get the four seasons (diagram on page 31 in your book) As the earth orbits around the sun, the sun light hits the northern and southern hemispheres differently When the sun is hitting the hemisphere directly then you are receiving strong rays and the warmth of summer Slanted rays means that it is winter

Summer Solstice Summer Solstice – June 21st North Pole is tilted toward the sun and at noon at the Tropic of Cancer the sun is directly overhead. -In Northern hemisphere only - longest day of sunlight fewest hours of darkness -In Southern Hemisphere it is the beginning of winter

Winter Solstice Winter Solstice – December 22 North Pole is tilted away from the sun and the at noon the sun is overhead at the Tropic of Capricorn In Northern Hemisphere only This is the day with the shortest hours of daylight and longest hours of darkness. This day is the beginning of summer in the southern hemisphere

Spring & Fall Equinoxes Spring Equinox – Vernal Equinox – March 22 Fall Equinox – Autumnal Equinox - September 23 Midway between the two solstice The days and nights are of equal lenghts. On both of these days the moon shines directly over the equator

The Sun

The Earth Third planet from the sun Has only 1 moon compared to Jupiter who as the most of any planet, and Mercury and Venus which have no moons The earth is 75% water 25% land Consists of 7 continents Only planet thus far that has life on it

Composition of the Earth Core- inner core- solid Outer core- liquid- iron Mantle – middle layer between the crust and the core Crust – outermost layer, 25 miles thick beneath the continents Light and brittle layer

Earth’s Movement Like all other planets, earth spins on its axis – the imaginary line that runs through the earths center between the north and south poles. Earth takes 24 hours to spin fully around on its axis thus we have 24 hour days. As the earth turns on its axis it has part of the planet facing the sun where it is daytime an part turned from the sun where it is night time.

Earth’s Movement Con’t The earth revolves around the sun as it rotates on its axis. This revolution around the sun takes 365 ¼ days. The revolution around the sun is what we call 1 year. The extra ¼ of the year is added up and gives us a leap year. Leap year is always February 29th.

The Atmosphere The atmosphere is the gaseous envelope surrounding the earth. It consists mainly of nitrogen and oxygen Life on earth depends partly on the atmosphere There are 5 layers Troposphere – where all weather occurs (people, plants and animals live here) Stratosphere – goes into the sky and is the ozone layer Mesosphere – above the earths surface Thermosphere – gets higher the further you go because it gets closer to the sun Exosphere – furthest layer of the atmosphere together with the thermosphere make the upper atmosphere

The Atmospheres Purpose Contains 99% nitrogen and oxygen which is needed for life Holds in the suns heat in order to keep life (greenhouse) without the atmosphere earth would be too cold for many things to live Reflects some heat back into the atmosphere keeping the earth from becoming too warm Shields dangerous sun rays

The Planets

Mercury

Mercury Closest planet to the sun 1/3 the size of the earth (2nd smallest planet, now the smallest) It has no moons Length of year is 88 days 800 degrees in the daytime, -300 degrees in the night time

Venus

Venus 2nd planet from the sun Sixth largest (slightly smaller than earth) Sometimes known as earth’s sister planet because they are similar in size, density, and volume. Has a very slow rotation 243 earth days per venus days. Temperature 900 degrees Fahrenheit

Earth

Earth 365 ¼ days per year Only planet with life Varying temperatures

Mars

Mars The Red Planet Contains the largest mountain in the solar system 4th planet from the sun 7th largest planet ½ the size of the earth 1 day on Mars is 24 hours just like EARTH! 2 tiny moons

Jupiter

Jupiter 5th planet from the sun By far the largest planet more than twice the size of all the planets combined 4 very large moons Gas planet – 90% hydrogen, 10%helium

Saturn

Saturn 2nd largest planet in the solar system 6th planet from the sun Length of year is equal to 29.42 earth years Days are 10 h and 39.4 minutes long Gas planet Has a series of rings around it 33 moons

Saturn’s Rings Ring Name: D Distance*: 67000 km Width: 7,500 km Ring Name: B Distance*: 92000 km Width: 25,500 km Thickness: 0.1 km - 1 km Mass: 0.1 kg Albedo: 0.65 Ring Name: A Distance*: 122200 km Width: 14,600 km Thickness: 0.1 km - 1 km Mass: 0.1 kg Albedo: 0.60 Ring Name: F Distance*: 140210 km Width: 30 km - 500 km Ring Name: G Distance*: 165800 km Width: 8,000 km Thickness: 100 km - 1,000 km Mass: 100 kg Ring Name: E Distance*: 180000 km Width: 300,000 km Thickness: 1,000 km Mass: 1,000 kg

Uranus

Uranus 7th planet from the sun 3rd largest planet 27 moons Ring system surrounding it

Neptune

Neptune 8th planet from the sun 4th largest Composition – various ices and rock Bluish color comes from methane gas Crosses orbits with pluto at times making it the farthest planet from the sun for several months. 13 moons Has rings but they are not as bright and colorful as Saturn’s because they are made of rock and dust mostly

Pluto

Pluto 9th planet from the sun Smallest planet Pluto has just recently been taken off of the list of the planets and made into a dwarf planet due to its small size

ERIS