night sky

1. The Night Sky!
DO NOW:
When you look at the
stars in the night sky,
you do not see them as
they are today. Why is
that?
LO: What objects can we see in the night sky?
Describe the objects that
you can see in the night
sky.
Describe the structure of
the Universe.
Explain
the choice of particular
units for measuring
distance.
Keywords:
Artificial
satellites
Natural satellites
Planets
Stars
KS3 Activate Science

2. DO NOW!
When you look at the stars in the night
sky, you do not see them as they are
today. Why is that?
The light from them has taken
years to get here. You are
looking back in time!
When you look up at the night
sky what do you see?
Make a list of objects in your
book.

3. What is out there? Put your helmet’s visors down, adjust your space suits and
hold on. We are going on a journey!

4. Satellites
The nearest objects that you can see
without a telescope are artificial
satellites. They orbit the Earth.
You can see the International Space
Station (ISS) with the naked eye
(without using binoculars or a
telescope). The light reflected from
the ISS reaches us in a fraction of a
second.
Light reflected from the Moon
reaches us in just over a second.
The Moon orbits the Earth. It is the
Earth’s only natural satellite.
Q1. State one example of an artificial
satellite and one example of a natural
satellite.
Q2. Describe the difference between an
artificial satellite and a natural satellite.

5. What is wandering across the sky?
There are five planets that most
people can see with the naked
eye: Mercury, Venus, Mars,
Jupiter, and Saturn.
Like the Earth they orbit the Sun. Venus gets closest
to the Earth, about two light-minutes away. Light
from Saturn takes about 1.5 hours. The planets
form part of the Solar System.
Q1. State the names of the five planets
that most people can see with the naked
eye.
Q2. Name the planets in our Solar System
(in order starting closest to the sun).

6. Lights in the sky
Most of the dots of light that we see are
stars in our galaxy, the Milky Way.
A galaxy is a collection of stars held
together by gravity; there are billions of
stars in the Milky Way.
Our Solar System orbits a large black hole at
the centre of the Milky Way. Some of
these stars have their own solar systems.
Planets, called exoplanets, orbit around
them. Q1. What is the name of our galaxy?
Q2. Describe what a galaxy is.
Q3. Explain what is meant by an exoplanet.

7. Lights in the sky
Some of the dots of light in the night
sky are other galaxies.
The Milky Way is just one of billions of
galaxies that make up the Universe.
Put the following in order starting with the
smallest:
Star, galaxy, solar system, planet,
universe, moon.
Our nearest large galaxy
is Andromeda, which
you can see with the
naked eye.

8. QUICK QUIZ: The night sky
1. The nearest objects that you can see without a
telescope are ___________________.
2. The moon is Earth’s only __________________.
3. You can see the ____________________ with the
naked eye.
4. There are five _____________ that most people can
see with the naked eye.
5. The planets form part of the ____________________.
6. Most of the dots of light that we see are _________
in our _____________, the _____________.
7. The Milky Way is just one of billions of galaxies that
make up the ________________.
Milky Way
planets
international
space station
solar system
galaxy
natural satellite
artificial satellites
universe
stars

9. ANSWERS
1. The nearest objects that you can see without a
telescope are ___________________.
2. The moon is Earth’s only __________________.
3. You can see the ____________________ with the
naked eye.
4. There are five _____________ that most people can
see with the naked eye.
5. The planets form part of the ____________________.
6. Most of the dots of light that we see are _________
in our _____________, the _____________.
7. The Milky Way is just one of billions of galaxies that
make up the ________________.
stars
solar system
international
space station
natural satellite
galaxy
artificial satellites
universe
Milky Way
planets

10. A comet is one of the most spectacular sights
in the night sky.
They are huge snowballs that orbit the Sun.
Meteors are bits of dust or rock that burn up
as they move through the Earth’s atmosphere
and produce streaks of light.
Any meteor that makes it to the ground is
called a meteorite.
Lights in the sky
Q – Describe the difference
between a comet, meteor and
meteorite.

11. Fantastic Fact!
It would take a car travelling at
100 m.p.h. over 100 years to
reach the Sun.

12. How fast does light travel?
• It takes light about 8 minutes to reach the Earth
from the Sun, a distance of 150 million km.
• It takes 4 years for light from our next nearest
star to reach the Earth. Light from Andromeda
takes 2 million years to get to Earth.
• The speed of light is about 300 000 km/s.
Astronomers use ‘light time’ to measure distances
in space because the distances are so big.
• A light minute is the distance that light travels in
1 minute.
• A light year is how far it travels in a year.
• Light-time is a measure of distance, not time.
One light year is over 9 million, million kilometres.
Distances are so big in the Universe that
it takes days on a spacecraft to get to
the Moon, and years to get to the planets.

14. TASK: Arrange the following objects in the correct order as you would see them on your
journey from planet Earth to Andromeda.
Asteroid belt
outer edges of the Solar System
the Moon
Andromeda
the Milky Way galaxy
Mars
outer planets
6
5
1
7
3
2
4
CHALLENGE: Draw a flow
diagram with pictures to
illustrate the objects above.

16. PEER
CHECK
I set off on a journey from the Earth to our nearest galaxy - ________. It will take
me around 2 million ______ ______ before I reach my destination. As my space
shuttle ascended it went through the Earth’s atmosphere in a great display of
glowing lights. I reached the _______ __________ zone and started to float in
my cockpit. The spacecraft went father away making the Earth look much smaller.
I saw the bright light of our ________ _________ - the Moon. I speeded up,
crossing the orbit of our ________ _______ - the Mars. It took a great deal of
skill to safely manoeuvre my spacecraft through the area of giant, rocky pieces of
cosmic rubble, known as an _____ ______. As I accelerated I entered the region
of our ________ _______. I went zooming past Jupiter, Saturn and ________.
I took a glimpse of poor demoted dwarf planet - _______. Eventually, I was far
enough to reach the outer edges of our ______ _______, with our star
_________ in the centre. From that point on I accelerated rapidly, zooming out
of our galaxy - ________ _____. What a spectacular view it was to see all the
____ ______ stars spinning in a giant whirlpool of light. Soon I reached the outer
edges of our galaxy and went zooming away through the unknown towards
Andromeda.
Missing words: the Sun, natural satellite, Uranus, asteroid belt, the Milky Way, outer
planets, light years, Pluto, 400 billion, the Andromeda, inner planet, Solar System,
zero gravity,

17. 3 Asteroid belt collection of stars and planets
5 outer edges of the Solar System the nearest galaxy
1 the Moon Jupiter, Saturn, Uranus, Neptune
7 Andromeda the Earth’s natural satellite
6 the Milky Way galaxy the boundary of the Solar System
2 Mars the 4th planet from the Sun
4 outer planets area between Mars and Jupiter
PEER
CHECK

18. Andromeda galaxy
The Solar System
The asteroid belt
The Earth
The Milky Way
The Moon
An asteroid
Meteors (shower)
The artificial satellite
PEER
CHECK

19. SUMMARY QUESTIONS
1. Copy and complete the sentences below:
Our Sun is just one ___________ that has planets around it. Planets around
other stars are called ___________. It takes light __________ to get to us
from the Sun, but ___________ to get to us from our nearest star outside the
Solar System. (4 marks)
Q2. Suggest why astronomers use light years instead of kilometres to measure
distance. (3 marks)
Q3. Compare the time it takes light to reach us from the different objects that
you can see in the night sky. (6 marks)

20. What might happen on Fr 13th of April 2036?
What are we afraid of? What do
we call this object?
What are the chances of this
happening?
What might be the
consequences?
What can we do to prepare
ourselves?