Space Intro

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Space

The universe contains around 100 billion galaxies Each galaxy can contain hundreds of billions of stars like our sun Planets can orbit stars and that is what makes our

solar system

The Hubble Telescope caught this image by looking at a single pixel of sky

Our Solar System

Our Solar System contains: • A Star: The Sun • Planets: Which go around the Sun • Satellites: Which go around planets • Smaller objects: Such as asteroids and comets The Solar System is often shown as being flat like this but it is really 3D

Order of the Planets

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

You can remember this using the sentence: My Very Excellent Mother Just Sent Us Nachos

Mnemonic

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune My Very Excellent Mother Just Sent Us Nachos Create your own mnemonic to remember the order of the planets M V E M J S U N

Add a diagram of the order of the planets to your mnemonic

Dwarf Planets

Until 2006 we used to say Pluto was a planet and that we had nine planets in the solar system This was done because we were discovering too many objects the size of Pluto We now call these Dwarf

Planets

Our Moon is bigger than Pluto but can’t be a planet because it orbits Earth not the sun

Asteroids

Our solar system has two main asteroid fields Asteroids are huge lumps of rock that aren’t big enough to be planets. They often contain metal ore

https://www.youtube.com/watch?v=DrbCAoiyUNw

Comets

Comets are collections of ice, dust and small rocky

particles

They tend to have very long highly elliptical orbits Halley’s comet is one of the most famous and is visible in the sky every 76 years

Heliocentric Model

We used to believe that the Earth was at the centre of the universe and everything orbited us Space exploration and use of telescopes means that we now understand that the Earth orbits the Sun Heliocentric is named after the Greek god Helios which means Sun

Night and Day

The Earth is constantly rotating on a tilted axis This causes night and day The Earth also orbits the

Sun

This causes seasons From space you can see a definite line between night and day as the

Earth rotates

The Earth is on a

tilted axis

Every 24 hours the Earth turns around this axis once

NIGHT DAY It is always day on the side of the Earth that faces the

Sun

The Sun appears to move across the sky but this is really the

Earth rotating

9am

The position of the sun also affects our

shadows

12 noon

E W

3pm

Time Zones

If it was 4:00 in London what time would it be in…

Place Casablanca Pretoria Antanarivo Philippines GMT +1 +2 +3 +8 Time 05:00 06:00 07:00 12:00

We belong to the GMT time zone which stands for Greenwich Meridian Time

Daylight Savings Time

Daylight savings time is when we move the clock forwards by one hour in spring take it back off in

autumn.

This is so that it is lighter during the evenings so lights don’t have to be used and people can shop.

Not every country uses daylight savings time. It is mostly used in America and Europe.

Daylight Savings Time

Task: Read the article and write a response back to Chris Hill explaining why he is wrong.

• • • Include: An explanation as to how he is mistaken.

What daylight savings time is.

Why it is used.

Seasons

Seasons are caused by the Earths tilted axis and its position in orbit around the Sun The seasons in the northern hemisphere are always the opposite of those in the southern

hemisphere

Everything above the equator is in the northern hemisphere everything below in the southern

hemisphere

Why do we get Seasons?

Seasons happen due to Earth being on a tilted axis When the northern hemisphere is pointed towards the Sun it is Summer in the UK When the southern hemisphere is pointed towards the Sun it is Winter Globes also rotate on a tilted axis to represent how the real planet does

Sunrise and Sunset

The tilted axis of the Earth makes the Sun appear lower in the sky during Winter

The Moon

The Moon is Earths

natural satellite

A satellite is something that orbits a larger body It is a natural satellite because it is not man made Scientists believe the moon was once part of Earth but was blasted off in a collision as the Earth formed

The Moon

The Moon is held in orbit around the Earth by

Earth’s Gravity

It does not produce its own light like stars do, it just reflects the suns rays This is why we can see it at

night

The moon can sometimes appear to be orange. This is caused by our atmosphere scattering the light it

reflects

Phases of the Moon

It takes the Moon 28 days to orbit the Earth Over these 28 days the Moon appears to change

shape

This is because only half of the Moon is facing the Sun and we can’t see the dark side This shows how the moon appeared over the course of a month

Eclipses

A solar eclipse happens when the Moon passes between the Sun and the Earth. This casts a shadow over the Earth A lunar eclipse happens when the Earth passes between the Sun and the Moon. This casts a shadow over the Moon.

Solar eclipses are very rare however lunar eclipses happen most years

Eclipses

Solar Eclipse Lunar Eclipse

Stars

The nearest star to us is the sun We sometimes think of stars as being very tiny, especially when we look up at the night sky This is only because they are very far away z

Galaxies

A galaxy is a collection of hundreds of billions of stars orbiting around a

supermassive black hole

at the centre Our galaxy is called the Milky Way and contains around 300 billion stars just like the Sun Our Galaxy will one day collide with its closest neighbour Andromeda

Gravity

Gravity is an attractive force that affects anything with mass Even people attract other objects with gravity but our mass isn’t large enough for the force to be very strong Isaac Newton discovered gravity when an apple fell on his head

Mass

Mass is the amount of matter (or stuff) an object contains Mass is measured in grams (g) An objects mass is the same wherever it is An Elephant contains more matter than a mouse so has more

mass

Gravity pulls down to the centre of the earth no matter where you stand on it

GRAVITY

Mass and Gravity

The effects of gravity only become significant when objects get to the mass of a moon or planet The more mass an object has the stronger its gravity will be The sun has the most mass out of anything in our solar system so it has the most gravity

Mass and Gravity

Gravity and Mass are directly proportional This means as you increase one the other increases at the same rate If you double the mass of an object you double its

gravity https://www.youtube.com/watch?time_continue=4& v=uhS8K4gFu4s

Distance and Gravity

Gravity gets weaker the further away you get from an object Every time you double the distance from an object the effect weakens by four

times

You don’t have to be far from earth to appear weightless

F = Force of Gravity F F/4F/16

Gravity Summary

Gravity is changed by two things:

Mass: When we double the mass we double the effects of gravityDistance: When we double the distance

we divide the effects of gravity by four

Orbits

Orbiting is when an object travels around another due to gravity Objects will only orbit things with a higher gravitational force than themselves E.g. The Moon orbits the Earth and the Earth orbits the Sun Orbits are usually circular but not always They can also be elliptical

Planet Orbits

The further away a planet is from the sun the longer it takes for it to orbit it The time for a planet to orbit a star is called a year A year on Earth is longer than a year on Mercury The length of a year on Earth is 365 days On Neptune a year is 60048 days long

Planet Orbits

The further away from the Sun a planet is the slower it

travels

Weight

Weight is a force caused by gravity Weight is the gravitational force between objects Because weight is a force it is measured in Newtons (N) People usually use the word weight wrong and get it confused with mass

Weight, Mass and Gravity

Wherever you are in the universe your mass will be the same But depending on how strong the gravity is you can weigh different amounts Because gravity is weaker on the moon astronauts weigh very little

Weight 3000N Mass 300Kg

On earth you wouldn’t be able to lift a safe because it would weigh too much

Weight 500N Mass 300Kg

On the moon the safe would have the same mass but its weight would be lower

Weight 500N Mass 300Kg

Because it weighs less you would be able to pick up the safe

Gravity Calculations

Weight (N) = Mass (kg) x Gravitational Field Strength (N/kg) Earths gravitational field

strength is 10N/Kg If a man had a mass of 80kg then you could enter those numbers into the formula to calculate his weight

Weight = 10 x 80 = 800N

M W x G W: Weight M: Mass G: Gravitational Field Strength

Satellites

Artificial Satellites are man-made objects that are launched in to space and

orbit Earth

They are held in orbit by

Earth’s gravity and their own velocity

Over time their orbit will decay and they can fall back to Earth This shows all the satellites and space debris in low Earth orbit

Uses for Satellites

Satellites have many uses including: • • • • • • • Communications Global Positioning System Predicting Weather Scientific surveys of the Earth's surface Map making Spying TV Satellites use solar panels as a renewable way to power their systems

Space Telescopes

A telescope in space has no light pollution or interference from the

atmosphere

They are incredibly expensive though The Hubble Space Telescope was launched in

1994

When the Hubble was first launched it didn’t work It needed ‘spectacles’ due to a mistake

Space Probes

Space probes are used to explore our solar system and beyond Because they are unmanned they can be made quite small and they don’t need to carry food or oxygen This makes them a lot cheaper than manned space

flights

Voyager 1 was launched in 1977 and is very close to entering interstellar space Every year it travels the same distance as there is between the Earth and Sun

Manned Space Flights

The space race between America and Russia culminated in Neil Armstrong setting foot on the Moon in 1969 Humans have yet to travel further due to the time, money and resources it would take Laika the dog was the first living thing to orbit the Earth and also to die in orbit

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