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
3pm
12 noon
sun also affects our
shadows
E
W
Time Zones
If it was 4:00 in London
what time would it be in…
Place
GMT
Time
Casablanca
+1
05:00
Pretoria
+2
06:00
Antanarivo
+3
07:00
Philippines
+8
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 gravity
• Distance: 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
Mass
300Kg
Weight
3000N
On earth you wouldn’t be able
to lift a safe because it would
weigh too much
Mass
300Kg
Weight
500N
On the moon the safe would
have the same mass but its
weight would be lower
Mass
300Kg
Weight
500N
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
W
M 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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