Science - Space Unit Flashcards
Name the 8 planets in order of distance
from the Sun
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
Define a planet
A body that orbits the Sun
What is the hottest planet and why
Venus. Because it’s atmosphere traps heat.
What is a geocentric model
A model where Earth is at the centre of everything and the other planets, moon and Sun all orbit around it.
What is a heliocentric model
The Sun is at the center of the Universe
The planets, including Earth, orbit the Sun
What is an ellipse?
A flattened circle or oval. Earth’s orbit around the sun is in the shape of an ellipse
How long is a day and year?
Day = 24 hours, Year = 365 days
State the shape of the earth’s rotation around the
sun.
An ellipses
Describe how we define a year.
One rotation around the sun.
Why do we experience day and night?
The earth rotates on it’s axis. When part of the
planet faces the sun it is day, opposite is night.
How much is the earth tilted?
23.5 degrees
Why do seasons occur
As the Earth orbits some parts of the Earth receive more sunlight each day than others due to it’s tilt.
In summer, the tilt causes the UK to be closer to the sun
Fill in the gaps
We have seasons because the _________________ orbits the
______________. It takes the Earth __________________ days (or
one year) to orbit the Sun because the Earth is ________________ on
its axis, at all times of the year one _______________________ is
always tilted either ________________________ or
_________________ from the Sun.
In the hemisphere that is tilted towards the Sun, it is
_________________ because the Sun’s rays hit that hemisphere more
strongly.
In the hemisphere that is tilted away from the Sun it is
___________________ because the Sun’s rays take longer to reach it
and so they lose some of their strength. That’s why it’s
__________________ in Winter!
We have seasons because the Earth orbits the
Sun. It takes the Earth 365 days (or
one year) to orbit the Sun because the Earth is Tilted on
its axis, at all times of the year one hemisphere is
always tilted either closer or
further from the Sun.
In the hemisphere that is tilted towards the Sun, it is
Summer because the Sun’s rays hit that hemisphere more
strongly.
In the hemisphere that is tilted away from the Sun it is
Winter because the Sun’s rays take longer to reach it
and so they lose some of their strength. That’s why it’s
Colder in Winter!
The Earth does not move closer or further away from the Sun, the distance
between the Earth and the Sun remains rather constant. With this in mind,
how can we still experience Summer and Winter?
As the Earth is tilted, only part of the Earth is now slightly closer to the sun, not the entire earth.
What affects your weight?
- Your Mass (How much of you there is)
- Gravity (How strong the planet you are on pulls you down)
- How far away your centre of mass is away from the centre of mass of the nearest planet.
What is a Centre of Mass?
The centre of mass is where gravity affects you from.
It is the middle of you.
Whats the difference between mass and weight?
Mass is how much of something there is. It is measured in kilograms.
Weight is a FORCE of gravity. It is how strongly gravity pulls an object towards Earth. It is measured in Newtons.
What is the equation for weight
Weight = Mass x Gravitational Field Strength
W = mg
What affects gravitational field strength?
The bigger the object you are next to, the larger the gravitational attraction is.
The closer it is to you the larger the gravitational field strength is.
What is gravity?
Gravity is the force which holds things in orbit.
The closer the planet is to the Sun. The larger the force of gravity it feels is.
How does the international space station have 89% of earth’s gravity?
It’s being pulled in a circle.
Gravity pulls it down but because the Earth’s round the Earth ‘falls away’ by the same amount.
The ISS is basically falling forever.
‘Constant freefall’
