Unit 5: SPACE EXPLORATION

Getting Home - Movie Clip from Apollo 13 at WingClips.com

1.1 Focus Question

What did our ancestors know about the sky?

(10000 years of looking at the stars in a few short slides!)

Frames of Reference• a set of axes of any kind that is used to

describe the positions or motions of things• Ex:

Stars as a Frame of Reference• To see how Mars moves, pick 2 bright stars and

record how close they are to Mars every night for a couple of weeks

• From this you can chart the motion of Mars and see how it moves in the sky

Tracking Cosmological Events• What is/are some cosmological event(s)?

• Two important ones were the summer & winter SOLSTICE

• Northern hemisphere– Summer solstice: around June 21– Winter solstice: around December 21

• How does this differ from the Southern Hemisphere?

What did our ancestors see?• From earth– Sun rises & sets– Moon has phases and travels across the sky– Planets shift against a background of stars– Even constellations appear to change position in

the sky throughout the year

Constellations• unchanging patterns that form objects in the

sky• have names and folk tales created by people

to explain them. Ex. Ursa Major (the Great Bear), Orion (the hunter) and the Big Dipper.

Models for Planetary MotionGEOCENTRIC MODEL / Earth Centered

– Earth at the centre– Concentric spheres surrounding it representing

moon, Sun, and planets of the time– 2000 years ago Aristotle

HELIOCENTRIC / Sun-centered Model• Started in 1530 with Copernicus (many other

scientists made contributions)• Sun at the center, everything revolved around it• Not spheres but ellipses

Homework• Pg.376 #2,6-9

1.2 Discovery Through Technology• Technological advances continue to help us

understand more of what is happening so far away

The Astronomer’s Tools• Pictures of some older tools on pg.378

(quadrant, astrolabe, cross staff)• With each new innovation, astronomers made

new discoveries and gained more knowledge• Big breakthrough TELESCOPE (16th century)

Measurement in Space• How would you measure the distance

between school and home?• How would you describe your height? – Need an appropriate unit of measurement for the

VAST SIZE of space

• Astronomical Units (AU)– Inside the solar system– 1 Au = distance from centre of Earth to centre of

Sun– See pg.379

• Light Years– Distance that light travels in one year (~9.5 trillion

kms)– Distance to star closest to Earth after the sun is 4

light years!!!

Looking into the Past• Because things are so far away and light can only travel

so fast what we see is “old”• When you see the moon you see it as it was a second

earlier bc the light had to travel to your eye– Light from the sun takes approx 8 min. to get to Earth– Light from Pluto 5 hrs– Some stars 25 000 years – Some images from Hubble 12 billion years

Homework• Pg.383 #1,8

1.3 The Distribution of Matter in Space

STARS!!

Stars at Different Times of the Year

SunSun

What is a STAR?• Hot, glowing ball of gas (hydrogen) that gives

off light• Stars vary in color depending on their surface

temperature

Life Cycle of a STAR• BIRTH– form in regions of space called nebulae (a lot of

gas and dust)– Gravity pulls together the gas and dust and they

react and if its reacts enough and gets hot enough it glows… a star is BORN

– Will become either a sun-like star or massive

• Death– Eventually a star runs out of fuel (hydrogen)– First it expands to a giant/supergiant– Next it starts collapsing into either a white dwarf or

supernova (star explosion)– Lastly it ends as either a

• Black dwarf cold, dark (not sure if they exist)• Neutron star anything left over from supernova• Black hole dense remains of star with so much gravity that

even light can’t escape

Galaxies• A grouping of millions or billions of stars, gas

and dust• Held together by gravity• The galaxy we live in is a spiral and is called

the Milky Way

Other bodies • What Is An Asteroid? – YouTube

• What Is A Comet? – YouTube

• What Is A Meteor? - YouTube

1.4 Our Solar Neighborhood• Planetary System – Consists of a number of

planets, moons, asteroids, and cosmic dust orbiting a star

• Earth’s planetary system is called the Solar System.

The Planets• each planet has its own unique features and characteristics

(p.394-396)• the solar system can be divided into two distinct planetary groups

– inner planets or terrestrial planets or Earth like• smaller, rockier in composition and closer to the sun• Mercury, Venus, Earth and Mars

– outer planets, or Jovian planets• large, gaseous and located great distances from the sun• Jupiter, Saturn, Uranus and Neptune

Inner/ Earth-Like / Terrestrial

Jovian / Gaseous Planets

The Sun• made up of mostly hydrogen• 1.4 million km in diameter (110x diameter of Earth • solar flares that flow from the sun• Solar wind the outflow of particles from the sun. • If the location in space “feels” the solar wind, then it is

considered to be in the solar system

Others• Asteroids• Comets• Meteroids/meteors/meteroites

1.5 Describing Position• Suppose you were talking on

the phone to your friend. From your windows you are looking at the night sky. Your friend finds an interesting stellar object and wants you to look at it. How can you be sure you are both looking at the same thing?

1.5 Describing Position• Two questions need to be answers– How HIGH in the sky is it?– Which DIRECTION?

– Solved using two simple measurements

Azimuth• Compass direction

Altitude• 0o at horizon• 90o straight up

• With these two measurements, stargazers can pinpoint objects in space.

• Zenith refers to the highest point directly overhead.

Try some!• P. 405 1-7• BLM 5-3

2.1

Getting There : Technologies for Space

Transport

What “things” have humans sent up to space?

First Things First…• First step figure out a way to get off the

planet• Relies on physics for every action there is an

equal and opposite reaction– Eg: balloon (very simple rocket)

RocketsThere are three basic parts to a rocket

• Structural & Mechanical Elements– Everything from the rocket itself to engines, storage tanks and the

fins on the outside• Fuel (uses a chemical reaction)

– Any number of materials including liquid oxygen or hydrogen– The mixture is ignited in a combustion chamber causing the gases to

expand and leave as exhaust• Payload

– The materials needed for the flight including crew cabins, food, water, air and people

Exhaust Velocity• The speed at which the exhaust leaves the

rocket and determines the rocket’s flight distance and altitude.

Into the FUTURE…• Can only go so far into space with our current

technology• Two new devices for propelling spacecraft

between the planets– Ion drives– Solar sails

Gravitational Assist / SLINGSHOT• A method that allows the spacecraft to gain

extra speed by using the gravity of a planet to slingshot around it

More RocketryRockets have been used to launch• Weapons• Space Shuttles • Satellites

Space Shuttle Discovery (May 31, 2008)

To Do…• An average thunderstorm releases more energy

than an atomic bomb.

• Read pages 408-417• Questions 4, 6, 8, 9

• QuickLab p. 411 Stabilizing Rocket Flight

2.2 Surviving There

In Space (pg.416)• Shuttles

• Space Probes

• Space Stations

ChallengesOutside our atmosphere is an environment that is

hostile to human life in many ways…

More Challenges• Need water and oxygen but neither are readily available

Water• Devices exist that recycle almost 100% of the water in the ISS

Producing Oxygen• Electrolysis electricity splitting water molecules into their

component elements : In spacecraft, this process can supply most of the oxygen a crew needs

Technology• Has moved us forward so we can exist in space• The Space Suit (pg.421)– much more difficult environment than on Earth

• Challenges?

The ISS• A research facility assembled in space• In-orbit assembly began in 1998

• in a low Earth orbit and is a joint effort of over 16 countries (including CANADA!!)

Canada in Space• CSA oversees the training of Canadian

astronauts • Satellites - RADARSAT-1/2• ISS – Canadarm2 and Dextre mechanical arms.• Phoenix Mars Mission – Weather Station• Videoclip

Benefits vs. Costs of Space ResearchBENEFITS

• More environmental monitoring of Earth.

• New understanding of Earth, solar system, and the universe.

• Medical and technological benefits

COSTS

• Expensive! Money could be spent on research on Earth.

• Possible weaponization of Space

• Dangerous (Apollo 1, Challenger, Columbia)

Homework• Using ‘Living in Space’ (and pgs 418-422)• as your central idea, generate a mind map to link

the ideas and concepts necessary for survival. – How To Mind Map, The Steps - YouTube

p.425 1-8

2.3 Space Technology & Human Needs

• Two types of satellites– natural satellite is any planet, moon, or asteroid

that orbits another larger celestial body– artificial satellite is a device made by humans, like

a spacecraft, telescope, or communication satellites that orbits. They mainly get their power from solar panels.

Remote Sensing• What is it? the science of taking measurements of Earth or

other planets, from space• Why?

– show healthy vs. unhealthy vegetation.– Clear-cut and burned forests can be mapped.– Water pollution can be imaged– Erosion can be tracked– Weather can be tracked

Types of Orbits - GEOSYNCHRONOUS• An orbit that matches exactly to the rotation

of the Earth.• About 35,000 kms above the Earth.• Will remain above the same spot on the Earth

day and night.

Types of Orbits – LOW EARTH• Revolves around the Earth in about 90

minutes.• Under 2000 km from the Earth.• Most satellites are found in this orbit = lots of

space debris!

• Topic 2 Section Review page 433• Questions 2-5, 7, 8.

3.1 TELESCOPES – Seeing the visible• Simple telescope uses 2 lenses– Objective lens: the large one at the front of the

telescope.– Ocular lens: is the eyepiece through which you

view the magnified object

• To build a more powerful telescope you need to increase it’s resolving power. – fineness of detail – depends on the diameter of the objective lens

• types of telescopes– Refracting: uses lenses• Problem: glass lenses can’t get bigger than 1 m or they

warp bc they are too heavy

– Reflecting: uses mirrors• Can detect very faint light• Uses a glass-like material that is lighter

Interferometry• Multiple telescopes whose images are

combined (Keck Observatory in Hawaii)

The Hubble• Orbits 600 km above earth• Free from Earth’s atmosphere (which blurs images)• Has sent back some of the best detailed pictures of the universe seen so far.

the Eagle nebula. These eerie, dark pillar-like structures are columns of cool, interstellar hydrogen gas and dust that serve as incubators for new stars.

More Telescope Info.• Today, large telescopes use charge-coupled

devices (CCD’s) instead of photo paper to record the images. These CCD’s are micro electric circuits that store the pictures.

Spitzer telescope• Video

Stump! • The Game: – One student is being asked questions by their

classmates– If they answer correctly they remain at the front of the

room, – If they are incorrect, the person asking MUST know

the answer to the question, if not the student remains at the front of the room.

3.2 Beyond the Visible• Many objects in space give off light other than the visible

spectrum

Radio Telescopes• Some objects in space emit radio waves (radio objects)• Used a radio dish to “listen” to the sky• Benefits not affected by weather, used day or night,

can “look” into empty space• Drawbacks not very detailed• Can be combined just like optical telescopes

(remember what that’s called?)

Variety of EMR• Microwave energy left over from formation

of universe• X-rays from black holes and pulsating stars• Bursts of gamma rays

Space Probes• Sometimes need to send equipment right to

the source– remote sensing on Mercury & Jupiter– Soil sampling on Mars– Nature of Saturn’s rings– See pg.444

3.3 Interpreting Space• Just by looking we can’t tell– How far away a star is– What it’s made of– Whether it is moving away or toward us

How far away?• Triangulation– Based on geometry of a triangle– Determine how far away an object is

• By measuring the angles between a baseline and the object (such as a tall tree or a water tower), you can determine the distance to that object.

Ex: Measuring how far it is across a river• On a flat area along the bank of the river, measure

off an accurate baseline and mark each end of the line so that you can identify it easily.

• Select an object to be your viewing object on the opposite bank.

• Standing at one end of the baseline, use a protractor to determine the angle between your sight line to the object and the spot on the baseline where you are standing.

• Stand at the other end of the baseline and again determine the angle from that spot to the object

• Make a scale drawing of a triangle using the length of the baseline and the two angles

• On your drawing, mark a perpendicular line from the baseline to the object.

• Measure this line and use the scale to convert it to actual length.

• This will give you the distance across the river

Hint:• The longer you make the baseline, the more

accurate your distance will be.

Try it!• A group of students went to a park to practice their triangulation skills. They

picked an object far away, set up a baseline, and measured the angle to their object at each end of the baseline, (see diagram). Their results are shown here.

Group

Baseline length (m) angle X angle Y

A 46 75º 78ºB 20 81º 77ºC 89 55º 71º

For each of the groups, use a scale diagram (on a separate piece of paper) to find the distance to the far object.

• Later the students measured the actual distances to the objects. Their results are recorded here.

• Compare your results with the measured results shown. How close were you?

• Which group might be expected to get the closest result to the actual measured distance? Which group might be expected to get the least close result? Explain your reasoning.

• Suppose that you were going to do this experiment. You pick a tree about 200 m away and set up a baseline 40 m long directly opposite the tree. What angles should you expect to be measuring?

Group measured distance (m)A 96B 51C 85

How far away cont.• Parallax– Apparent shift of a nearby object when the object

is viewed from different places– Demo– Astronomers look at the shift in position of a star

relative to background stars to determine angles for triangulation

Parallax – Contd.• The longest baseline we can use from Earth is

the diameter of Earth’s orbit• This means that measurements must be taken

six months apart to achieve the maximum baseline length

What is a star made of?• Uses the spectrum (ROY G BIV)• Send light through a spectroscope to break it

up into all the colors of the rainbow• Scientists noticed dark bands (spectral lines)

that were specific to each element• Video

Try it Together

Try it!• Read page 381 Think and Link. • Complete Analyze questions #1-6 • Complete Analyzing Spectral Patterns (on handout)

Analyzing Spectral Patterns1. List the chemical elements in:

a) Mystery Star 1

b) Mystery Star 2

c) Mystery Star 3

2. There is something strange about Mystery Star 4’s spectrum. What chemical is in Mystery Star 4?

What is odd about the spectrum?

Is it moving?• The Doppler Effect

What happens to the siren sound when an ambulance gets closer to you and then continues past you?

Go to page 382 and look at the truck diagram. Video clip

• For sound, the waves being compressed or stretched out changes pitch

• For light, it changes color (R at one end of the spectrum, V at the other)

• If a star is approaching you the star’s spectrum shifts toward the shorter wavelength end of the spectrum –the blue end.

• If a star is going away from you, the spectral lines will be red shifted- moving toward the longer-wavelength part (red end) of the spectrum.

• Turn to page 383 and look at it and read Figure 5.26. It is definitely interesting

4.0 Impact of Space Exploration on Society & Environment

• Risks & Dangers of Space Exploration– High risk– Space is not human friendly (radiation, re-entry,

floating debris)– Space junk space and Earth

• How, as a society, can we benefit from space exploration? (see pg.464-465)

Political, Ethical & Environmental IssuesPolitical Ethical Environmental

Space Exploration• To go where no one has before? Or not?• Activity: – Four corners debate:• To prepare read pages 464- 467