6 Space physics
6.1 Earth and the Solar System
6.1.1.The
Earth and
Solar
System
Oblate Spheroid
Adapted from https://media.geeksforgeeks.org/wp-content/uploads/20210522071513/UntitledDiagram8.jpg
6.1.1.1 Know that the
Earth is a planet that
rotates on its axis,
which is tilted, once in
about 24 hours, and
use this to explain
observations of the
apparent daily motion
of the Sun and the
periodic cycle of day
and night
https://medium.com/@reply19/the-phenomenon-of-days-and-nights-an-in-depth-
6.1.1.2 Know that the
Earth orbits the Sun
once in about 365
days and use this to
explain the periodic
nature of the seasons
https://avatars.mds.yandex.net/i?id=a8be9da1a7ac4b53640dff3639602a69a343c53b8d48e623-3537197-
6.1.1.2b
The
Latitude
Effect.
https://mrgeogwagg.wordpress.com/2015/07/02/lesson-5-uk-
6.1.1.3
Know that it takes
about one month
for the Moon to
orbit the Earth and
use this to explain
the periodic nature
of the Moon’s cycle
of phases
6.1.2 The Solar System
More Information about the
Solar System
https://www.youtube.com/watch?v=sCkhEu3lYNc
Formation of the Planets (3:28) Lincoln Learning Solutions
https://www.youtube.com/watch?v=AgwSdQzN4H4&t=40s
GCSE Physics - Astronomy: How the Universe is made of Galaxies, Solar Systems, Stars and Planets #85 (3:33)
https://www.youtube.com/watch?v=AMlXzHU-GIU
How fast are you moving through space right now? (2:03) Business Insider
6.1.2.1(abc)
Describe the Solar System
as containing:
(a) one star, the Sun
(b) the eight named
planets and know their
order from the Sun
(c) minor planets that
orbit the Sun, including
dwarf planets such as
Pluto and asteroids in
the asteroid belt
https://i.ytimg.com/vi/dCCRiL9vkaM/maxresdefault.jpg
6.1.2.1(abc)
Describe the Solar System
as containing:
(a) one star, the Sun
(b) the eight named
planets and know their
order from the Sun
(c) minor planets that
orbit the Sun, including
dwarf planets such as
Pluto and asteroids in
the asteroid belt
https://solarstory.net/img/articles/big/configuration-of-the-solar-system.jpg
My Very Educated Mother Just Served
Us Noodles.
My - Mercury
Very - Venus
Educated - Earth
Mother - Mars
Just - Jupiter
Served - Saturn
Us - Uranus
Noodles - Neptune
6.1.2.1abc [cont’d]
Describe the Solar System
as containing:
(a) one star, the Sun
Poom, what is the asteroid belt?
Namo, what are comets, and what is the shape of their orbits?
Tham: what is the Oort cloud, and how is it different from the Kuiper Belt?
(b) the eight named
planets and know their
order from the Sun
(c) minor planets that
orbit the Sun, including
dwarf planets such as
Pluto and asteroids in
the asteroid belt
Prem, what is Makemake?
Pang, what is Eris?
Minhji: what is the Kuiper Belt?
https://theplanets.org/solar-system/
Notice
the
astero
id
belt.
https://rhea.ryanmarciniak.com/2014/12/asteroid-belt-vs-kuiper-
Notice
the
Kuiper
Belt.
(“ky-
https://rhea.ryanmarciniak.com/2014/12/asteroid-belt-vs-kuiper-
Kuiper Belt
The Kuiper Belt is a large region in the cold, outer
reaches of our solar system beyond the orbit of
Neptune. It's sometimes called the "third zone" of the
solar system.
Astronomers think there are millions of small, icy
objects in this region – including hundreds of thousands
that are larger than 60 miles (100 kilometers) wide.
Some of the objects, including Pluto, are over 600 miles
(1,000 kilometers) wide. In addition to rock and water
ice, objects in the Kuiper Belt also contain a variety of
other frozen compounds like ammonia and methane.
There are more than 100,000 large objects in the Kuiper Belt (>100 km diameter).
https://science.nasa.gov/solar-
6.1.2.1(de)
288 planetary moons
(d) moons, that
orbit the planets
(e) smaller solar
system bodies,
including comets
and natural
satellites
https://i.pinimg.com/originals/f5/df/a9/f5dfa9f683fb3e55b2b52affa3ec8e58.jpg
6.1.2.2a Know that, in
comparison to each
other, …
(a) the four planets
nearest the Sun are
rocky and small and
(b) the four planets
furthest from the Sun
are gaseous and large, …
r ≈ 2,400km.
3,400km
r ≈ 6,000km
r ≈ 6,400km
r≈
6.1.2.2a Know that, in
comparison to each
other, …
(a) the four planets
nearest the Sun are
rocky and small and
(b) the four planets
furthest from the Sun
are gaseous and large, …
r ≈ 70,000km
r ≈ 58,000km
r ≈ 25,000 r ≈ 25,000
6.1.2.2b Explain this
Accretion Model
difference (in the terrestrial
and Jovian planets) by
referring to an accretion
model for Solar System
formation, to include:
(a) the model’s dependence
on gravity
(b) the presence of many
elements in interstellar clouds
of gas and dust
(c) the rotation of material in
the cloud and the formation of
an accretion disc
https://esahubble.org/images/o
6.1.2.3a
Know that the
strength of the
gravitational field
(a) at the surface
of a planet
depends on the
mass of the
planet
http://www.seasky.org/solar-system/planet-weight-
6.1.2.3b
Know that the strength
of the gravitational
field
(b) around a planet
decreases as the
distance from the
planet increases
https://www.iitianacademy.com/cie-as-a-level-physics-9702-topic-13-gravitational-fields-unit-13-3-
6.1.2.4
Calculate the time it
takes light to travel a
significant distance
such as between
objects in the Solar
System
Light travel time from sun to Earth ≈ 8 min.
6.1.2.4
Calculate the time it
takes light to travel a
significant distance
such as between
objects in the Solar
System
Light Travel Time from Earth to Planets
6.1.2.4
Calculate the time it
takes light to travel a
significant distance
such as between
objects in the Solar
System
“A radio signal takes
about 22.5 hours to
reach Voyager 1, which
is over 15 billion
miles (24 billion
kilometers) from Earth,
and another 22.5 hours
for a signal to come
back to Earth.”
https://www.jpl.nasa.gov/news/nasas-voyager-1-resumes-sending-engineering-
6.1.2.5 Know that the
Sun contains most of
the mass of the Solar
System and this
explains why the
planets orbit the Sun
https://space-facts.com/the-
6.1.2.5 Know that the
Sun contains most of
the mass of the Solar
System and this
explains why the
planets orbit the Sun
http://www.seasky.org/solar-system/planet-weight-
6.1.2.6
Know that the force
that keeps an object in
orbit around the Sun is
the gravitational
attraction of the Sun
https://homework.study.com/explanation/if-the-sun-attracts-the-earth-due-to-the-force-of-attraction-then-whydon-t-we-collide-with-the-sun.html
6.2 Stars and
the Universe
6.2.1 The sun as a star
Minhji, if Betelgeuse has 10,000 x the diameter of Earth, how much bigger is its volume?
d=
1,400,000 km
d=
12,000,000 km
d = 12,000,000,000 km
6.2.1.1a Know that the
Sun is a star of medium
size, consisting mostly
of hydrogen and
helium, …
https://knaughton.home.blog/2019/03/14/the-energy-
6.2.1.1b
Know that the Sun is a
star of medium size, …
and that it radiates
most of its energy in
the infrared, visible
and ultraviolet region s
of the electromagnetic
spectrum
https://www.infradream.com/tag/isik-
6.2.2 Stars
6.2.2.1 State that:
(a) galaxies are each
made up of many
billions of stars …
https://space-india.com/galaxies-the-cosmic-
Milky Way Galaxy
https://cosmosatyourdoorstep.com/wp-content/uploads/2023/02/andromeda-galaxy-
Art of the Black hole at
the center of our Galaxy
Scientists
have
been
studying the Milky Way for
centuries, and in the early
20th century, they began to
notice
something
strange
about the movement of stars
at
the
center
of
the
galaxy. These stars were
moving much faster than
expected,
and
scientists
couldn’t explain why.
It wasn’t until the 1960s
and 1970s that scientists
began
to
develop
the
mathematical
models
that
could explain this strange
behavior, and it was then
that
they realized that
https://www.youcanseethemilkyway.com/blog/exploring
-the-massive-black-hole-at-the-center-of-milky-way
https://www.youcanseethemilkyway.com/blog/exploring-the-massive-black-hole-at-
6.2.2 Stars
6.2.2.1 State that …
(b) the Sun is a star
in the galaxy known
as the Milky Way
6.2.2 Stars
6.2.2.1 State that …
(c) other stars in the
Milky Way are much
further away from the
Earth than the Sun is
from the Earth
https://ktlaneastro.wordpress.com/2022/01/30/blog-1-the-mystery-
6.2.2 Stars
6.2.2.1 State that …
(d) astronomical
distances can be
measured in lightyears, where one
light-year is the
distance travelled in
(the vacuum of) space
by light in one year
https://ktlaneastro.wordpress.com/2022/01/30/blog-1-the-mystery-
https://i.ytimg.com/vi/a5Hk4VNl3I8/hqd
efault.jpg
The Milky Way is about 1,000,000,000,000,000,000
km across
Or about 100,000 light years across
Or about 30 kiloparsecs (kpc) across. (see the
The parsec is a human
definition.
We say that if an object in the
night sky
seems to shift in position
from June to December
by 1/3,600 degree,
it is 1.0 parsec away from us.
Helpful Video
https://www.youtube.com/watch?v=iwlMmJs1f5o
Stellar parallax and measuring distance (1:58)
Las Cumbres Observatory
6.2.3 The Universe
https://thesciencebehindit.org/wp-content/uploads/2019/09/1-Tarantula-
6.2.3.1 Know that the
Milky Way is one of
many billions of
galaxies making up
the Universe and that
the diameter of the
Milky Way is approx.
100 000 light-years
Our galaxy contains 100 to 400 billion stars,
and is about 100,000 light-years across.
https://kids.nationalgeographic.com/space/article/milky-way
6.2.3.2 Describe
redshift as an
increase in the
observed
wavelength of
electromagnetic
radiation
emitted from
receding stars and
galaxies
On the left is a ray of light from
the Sun, and on the right one
from a far off galaxy.
As you can see, all the lines
shift towards the red end of the
spectrum due to red shift.
https://simple.wikipedia.org/wiki/Red_shift
6.2.3.3. Know that
the light emitted from
distant galaxies
appears redshifted in
comparison with
light emitted on the
Earth
On the left is a ray of light from
the Sun, and on the right one
from a far off galaxy.
As you can see, all the lines
shift towards the red end of the
spectrum due to red shift.
https://simple.wikipedia.org/wiki/Red_shift
Spectral Red
Shift
6.2.3.1 Know that the
Milky Way is one of
many billions of
galaxies making up
the Universe and that
the diameter of the
Milky Way is approx.
100 000 light-years
Our galaxy contains 100 to 400 billion stars,
and is about 100,000 light-years across.
https://science.nasa.gov/universe/exoplanets/our-milky-way-galaxy-how-big-is-space/
https://kids.nationalgeographic.com/space/article/milky-way
https://cosmosatyourdoorstep.com/
wpcontent/uploads/2023/03/galaxy_di
stances.jpg?w=960
6.2.3.2
Describe redshift as an
increase in the observed
wavelength of electromagnetic radiation
emitted from receding
stars and galaxies
https://science.nasa.gov/universe/exoplanets/our-milky-way-galaxy-how-big-is-space/
https://kids.nationalgeographic.com/space/article/milky-way
6.2.3.3 Know that the
light emitted from
distant galaxies
appears redshifted in
comparison with light
emitted on the Earth
https://louisville.edu/planetarium/research/implementation/visualization-scripts/high-school/hs-module-1
6.2.3.4 Know that
redshift in the light
from distant galaxies
is evidence that the
universe is expanding
and that this supports
the Big Bang theory
https://www.astronomy.ohio-state.edu/ryden.1/ast162_8/Hubble1929.gif