Space and Exploration P1

Grade 9

Frame of reference

A set of axes of any kind that is used to describe positions or motions of things

Celestial bodies

All objects seeing in the sky (e.g. sun, moon, stars, planets)

Constellations

Grouping of stars which form a pattern, which appear like objects

What did ancient people see?

They observed celestial bodies “moving” or “dancing” at night. They studied and many cultures created stories and legends about what they saw (mainly talking about European contributions but they are not the only one) 

What is the turtle constellation? 

Makinak

Makinak

• The turtle constellation

• The living calendar

• Made up of 5 stars

• Turtle shells have 13 pieces and there are thirteen months in Cree culture

  • Also aligns with the story of turtle island

What is geocentric view?

Aristotle proposed Earth must be the centre of the solar system, and all celestial bodies must orbit Earth. Earth was believed to be a perfect and divine sphere.

Retrograde motion

The apparent backwards motion of a planet in relation to the background stars- caused by Earth overtaking or being passed by another planet while in orbit.

Explain the diagram

Geocentric model, planets orbit earth- the little spirals are what Aristotle used to explain why the planets looked like they were travelling backwards. 

Explain the diagram

Heliocentric model, planets orbit the sun

What is heliocentric view?

• Copernicus proposed the sun was actually the centre of our solar system 

  • He struggled to support his hypothesis with evidence as scientific methods and technology were limited

  • Supported and refined by Galileo and Kepler

What is important for our observations?

Apparent daily motion was crucial for our observations and their explanations

Telescope

A device used to magnify objects at a great distance

Objective lens

The large lens at the end of the telescope

Ocular lens 

The eyepiece of a telescope 

When was the first telescope invented?

1608 in the Netherlands

What did Galileo do?

He made his own telescopes and began conducting experiments and observing the planets

• He concluded that the speed of light is finite

• Jupiter has many moons

  • He disapproved Aristotle’s ideas and supported Copernicus

Resolving power

The fineness of detail a telescope can produce of the object in view

How do you get better image quality in a telescope?

We can increase the resolving power by increasing the diameter of the objective lens (this is how we get more powerful telescopes) 

Focal length 

The distance from an optical system’s centre to it’s focal point- where light converges to form a sharp image 

Bigger focal length= 

thicker (bigger telescope)

Magnification= 

Focal length of objective lens/ Focal length of eyepiece (O/E)

What is the problem with increasing magnification?

Increasing the focal length without using a larger diameter just gives us bigger, low quality image

Label diagram

Label diagram

Label diagram

4. Combination telescope 

Refracting telescope features

Objective lens- Light is redirected/ bent towards the eye 

Pros- Higher resolving power 

Cons- More mass, size is limited (not practical and heavier)

Reflecting telescope features

Objective mirror- Light is reflected/”bounced” towards the eye

Pros- Less mass

Cons- Less resolving power

Combination telescope features

Has both mirrors and lenses

Pros- Super duper powerful resolving power

Cons- Expensive, difficult to maintain/use

Optical

Using/detecting visible light

Adaptive optics  

Techniques used to correct distortion from the atmosphere 

How is the size limited? 

The size of a telescope is limited by the mass of it’s components- and can affect resolving power 

Interferometry

When we connect two or more telescopes with computers- raises the resolving power (we can simulate an objective the size of distance between the two)

Spectroscope

A device that produces a focused spectrum and can measure the exact wavelength of energy absorbed and re-emitted by various chemical elements (converts it to kinetic energy then back to visual)

When was the spectroscope created?

It was created by a German scientist in 1859- based on Sir Isaac Newton, he figured out passing sunlight through a prism created a spectrum of colours 

How can we detect the chemical make up of a celestial body?

We can use the spectroscope 

Label diagram

Label Diagram

Label Diagram 

What does this diagram explain?

It shows what elements stars are made of based on their spectral lines (weaker lines show that there is less of a element in it- I didn’t show the weaker lines in the diagram) 

Electromagnetic radiation

Varying types of energy waves emitted by stars

Label the diagram

Radio telescopes

• Detect radio waves from celestial bodies

• Has lower resolution and quality because waves are long and low energy

  • Penetrates dust clouds where visible light can’t

• Able to detect bodies that are older, and they can detect through gas or atmosphere with low interference

Label the diagram

How far are Earth and Mars?

At their closest point Earth and Mars are 80 million km apart, they can be further though 

How far apart is the sun and Earth? 

150 million km 

How far apart is the sun and Mars? 

230 million km 

Stars

Stars are massive balls of gas which release energy from nuclear fusion

The sun is…

The sun is the only star in our solar system

Inner planets

AKA the terrestrial planets

Mercury- Smallest planet, closest to the sun, barely any atmosphere

Venus- Hottest planet, thick CO₂ atmosphere (traps heat)

Earth- In the Goldilocks zone, habitable

Mars- Most habitable planet after Earth, has ice (water) and is close to Earth

Outer planets 

AKA Jovian Planets 

Jupiter- Largest planet, has the “red spot” a giant atmospheric storm 

Saturn- Large planet, famous for it’s rings 

Uranus- Blue, turns on it’s right side 

Neptune- Blue, has many storms 

Galaxy

A system of stars, dust and gas held together by gravity

Which galaxy do we live in?

The Milky Way

Sun

• Is a star

• Largest celestial body in our solar system

• Source of energy

• Made of hydrogen

What is the difference between Earth’s atmosphere and other planets? 

Earth’s atmosphere is habitable, while the other option is Mars though it has a thin atmosphere- not ideal for temp regulation

What is the difference between Earth’s temperature and other planets?

Earth is in the Goldilocks zone (15℃- 20℃) while Mars has a variable temperature (-153℃-20℃) but also has seasons like Earth

What are the other possibilities other than planets to live on?

Moons, mainly Jupiter’s and Saturn’s.

Atmosphere- Titan

Temperature- Europa

The only reason we don’t consider those as much as Mars as they are too far away

What is the difference between the Inner and Outer Planets?

The inner planets are rocky, solid, have no rings, have 0-2 moons and are smaller. The outer planets are gaseous/liquid, have many moons and rings (in general).

How many moons does Saturn have? 

Saturn has 274 moons 

Asteroids and meteors

• Found mostly in the asteroid belt

• Made of rock, metal (meteoroids)

• Meteors have a tail of light

• Asteroids are bigger than meteors

• Meteorite → Meteoroid after it passes through the atmosphere, breaks apart

Comets

• Dirty ice-balls

• When they near the sun they heat up and leave a visible tail of shedded ice and gas

• Bigger than both asteroids and meteoroids

Jupiter spins on its axis ______ than Earth does, and it has an orbit that is ______ than Earth

Jupiter spins on its axis faster than Earth does, and it has an orbit that is larger than Earth

What part of the universe have the largest diameters?

Galaxies

Why is the image in a telescope enlarged?

The image is enlarged because light entering it is refracted and converged by the lenses (refracting telescope)

What does a spectral analysis do? 

It helps determine the chemical composition of a star 

Flame spectroscopes help with?

With determining the chemical composition of stars

Optical telescopes help us?

Observe far-away celestial bodies

When is using a telescope with an ocular lens of 25mm and an objective focal length of 1200mm, the magnification will be:

1200mm/25mm= 48 (Division not multiplication)

What do you need to do to increase the magnification of a telescope? 

You need to increase the diameter of the objective lens

The Doppler Effect

The apparent shift in the frequency of the wave caused by the relative motion of the source of the wave compared to the observer

What happens if the wavelength is shorter as a sound? 

It would seem to have a higher-pitched frequency 

What happens if a wavelength is shorter as visible light?

It would seem more blue in colour

How can you tell if stars are moving?

When a star is moving, it’s spectrum (recall emission and absorption) will shift depending whether the waves stretch (moving away) or compress (moving closer)

Why are most things red-shifted?

Because the universe is constantly expanding

Stationary

What we would normally expect to see from a spectrum in a lab- not in motion

Red-shifted 

All lines are the same but shifted towards the red/lower energy end of the spectrum

Blue-shifted 

All lines are the same but shifted towards the blue/higher energy end of the spectrum

Label the diagram

1. Stationary

2. Moving away (Red-shifted)

3. Moving towards (Blue-shifted)

Parallax

The apparent shift in position of an object based on the location of the observer

What can we use to estimate the distance of far away objects fro Earth?

Parallax

How far apart should you measure E and E’

Six months apart (Half of Earth’s orbit)- to get the biggest possible baseline with maximal apparent shift (minimal error).

Explain the diagram

When an object is closer the more it seems to switch. The diagram shows the shift of the thumb in comparison to the clock.

S= 

d/t

T=

d/s

D=

s x t

Label the diagram

Astronomical units

(AU), 150 000 000km- Earth’s distance from the sun 

Light year

63 241 AU- distance light travels in 1 year

What is triangulation

How you measure distance using parallax

Non-trigonometry

1. Create a baseline between the sides of the baseline and object

2. Measure the angles between the sides of the baseline and object

3. Draw a scaled diagram of the triangle you made

4. Calculate distance based on scale

Scale= Actual distance/Distance in diagram

Actual length= Measured distance x scale