Earth and Space Law of Gravitation Masses attracts

Earth and Space Law of Gravitation- Masses attracts each other. Gravity increases when the object is bigger or closer.

Our Planet: The Earth • The Earth rotates at 1, 675 km/hour at the equator, but 900 km/hour in the UK • The Earth weighs 5. 9725 billion trillion tonnes • The Solar System and the Earth is 4. 6 billion years old • The universe is 13. 7 billion years old

Days • This is how long it takes for a planet to make one complete spin around it’s axis • The Earth takes 24 hours to spin around • When we are facing the Sun it is daytime • When facing away from the Sun it is night time • The Sun rises in the East (Japan is the land of the rising Sun) and sets in the West

The Path of the Sun • We are in the northern hemisphere so at midday the Sun is South of us • The Sun is high in the Sky in Summer and days are longer

Years • The Sun is the largest body in our Solar System, so everything orbits it • This is due to gravity • It takes the Earth 365¼ days to orbit the Sun • The quarter is for the leap years we have every four years

Lunar Eclipse • We can see the moon at night because it reflects the Sun’s light • During a lunar eclipse the Earth blocks the Sun’s light and the moon goes dark

The Moon • Tides are caused by the moon’s gravity

The Moon in the Penumbra

Solar Eclipse • A Solar Eclipse is when the moon blocks the Sun’s light from reaching a part of the Earth • The last solar eclipse in the UK was during the Summer of 1999

The 1999 Eclipse

The Moon’s Shadow from Space

The Solar System • There is one star in our solar system, the Sun • Nine planets orbit the Sun • Asteroids and space debris also orbit the Sun • Our solar system is one of many inside our galaxy (the Milky Way)

The Planets • This mnemonic will help you remember the planets • My Very Easy Method Just Speeds Up Naming Planets • This should be • Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto • In 2006 Pluto lost it’s planetary status • The shape of the orbits are ellipses

The Inner Planets • These are Mercury, Venus, Earth and Mars • They are all made of rock • Mercury has no moon • Venus if 400°C during the day, making it the hottest planet in the solar system • Mars has two moons, Deimos and Phobos

The Gas Giants • These are Neptune, Saturn, Jupiter and Uranus • Jupiter is 318 times bigger than the Earth, making it the biggest planet in our Solar System • Saturn has conspicuous rings • All these planets are extremely cold

Asteroids • These are smaller than planets • There is an Asteroid belt between Mars and Jupiter • Most of the asteroids have a 1 km diameter • The Kuiper belt of asteroids is located at the edge of our Solar System Asteroid 2004 is moving in the middle of the picture (a satellite flies by)

Terminology • There is asteroid belt between Mars and Jupiter • Comets are made of ice, rock and gases • Asteroids are minor planets made of rock • Meteoroids are small, solid objects that follow comets • Meteors enter the Earth’s atmosphere • Meteorites hit the Earth’s surface

Comets • These are small objects made of rock, dust and ice • Hale-Bopp (right) passed us in 1997 • It will pass us again in 2537 years • Halley’s comet could be seen in 1986 • We will see it again in 2062 (it has a 76 year orbit)

Meteorites • • These are shooting stars or falling stars They leave craters This is a meteor shower They are thought to have killed off the dinosaurs

The Milky Way

An Ellipse

The Lunar Cycle • • A satellite is an object that orbits a planet The moon is the Earth’s largest satellite It takes 28 days to orbit the Earth This leads to the phases of the moon Crescent First Quarter Gibbous

Seasons • The Earth is tilted at an angle of 23. 5° • This means we are tilted towards the Sun at times and away from the Sun at other times • We are in the Northern hemisphere, the seasons in the Southern hemisphere are opposite to ours

Seasons

The Seasons • • • There are four seasons: Summer- we are tilted towards the Sun Winter- we are tiled away Spring- comes before Summer Autumn- comes before winter

• What happens when the northern hemisphere is tilted away from the Sun: • In Australia? • It is Summer • To us in the U. K. ? • It is Winter

Equinox • This is when the Sun is directly above the Equator • It happens on two days each year • Vernal Equinox on 20 th or 21 st March • Autumnal Equinox on 22 nd or 23 rd September

Solstice • The Winter Solstice is on the 21 st or 22 nd December • It is the first day of winter • It is the shortest day (least sunlight) • The Summer Solstice is on the 21 st of June • It is the longest day • The opposite happens in the Southern hemisphere

The Seasons • Which season is the Northern hemisphere in at position 1? • Winter • Which position is it in at point 2? • Spring

Beyond the Solar System • At the edge of the solar system is the Oort cloud, which strecthes 2 light years into the cosmos • The nearest star is Proxima Centauri which is part of a 3 star cluster called Alpha Centauri • It is 4. 3 light years away and it would take 25, 000 years to get there

Weird facts • The Voyager spacecraft took 12 years to reach Pluto (although this was faster because the craft slingshot around some planets) • Most solar systems have 2 suns like the movie Pitch Black • Neptune is 5 times further from Jupiter than Jupiter is from us (it gets 3% sunlight) • Pluto is 1% the size of the Earth

Weird Facts (2) • The universe is 1, 000, 000, 000 miles across