Ch. 21 Exploring Space 2010

Chapter 21: Exploring Space

I. Radiation from Space (pg 584)

A. Electromagnetic Waves1. Light from the past

a. Light seen from stars, may have left that star many years ago.

b. Light and other energy leaving a star are forms of radiation.

c. Radiation is energy that’s transmitted from one place to another by electromagnetic waves.

d. Because of this radiation, its called electromagnetic radiation.

I. Radiation from Space (pg 585)

B. Electromagnetic Radiation1. Sound waves, a type of mechanical

waves can’t travel through empty space. a. Then how do we hear the voices of

astronauts while they are in space? b. When they speak into a microphone, the

sound is converted into electromagnetic waves called radio waves.

c. They are then converted back into sound by electronic equipment and audio speakers.

I. Radiation from Space (pg 585)

B. Electromagnetic Radiation2. Types of electromagnetic radiation

a. Radio waves, visible light, gamma rays, X-rays, ultraviolet waves, infrared waves, and microwaves.

3. Measured in wavelength and frequency. a. Wavelength is the distance from the top of one wave

to the next. b. Frequency is the number of wavelengths that pass by

a certain point in one second. c. As wavelength increases; frequency decreases and

vice versa.

Wavelength

Frequency

I. Radiation from Space (pg 585)B. Electromagnetic Spectrum

I. Radiation from Space (pg 585)

C. Speed of Light1. Light is part electricity and part magnetism2. Speed of light is 3.8 X 108 m/s or 300,000 km/s3. All electromagnetic waves travel at the speed of

light. 4. Universe is so large it takes millions of years from

the light from some stars to reach the Earth. 5. Once electromagnetic radiation from stars and other

objects reach Earth, we can use it to learn about the source of the electromagnetic radiation.

I. Radiation from Space (pg 585)

I. Radiation from Space (pg 585)

C. Speed of Light5. One tool used for observing electromagnetic

radiation from distant sources is a TELESCOPE.

End Day One Lecture HOMEWORK: Monday January 4th, 2010Due: Wednesday January 6th, 2010Key Science Words--pg 609-- (a to n) Homework Quiz Friday January 8th, 2010

Water Found on Mars!

21.1 Radiation from Space

D. J. Electromagnetic Waves (Quick Review)1. Light from the Past

a) a. Stars are images of the pastb. Light from stars takes time to travel through

spacei. Our sun = 150 Million Km away = 8

minutes travel timeii. Alpha Centauri (our closest neighboring

star) = 40 Trillion Km away = 4.2 years travel time

c) Light travels at 300,000 km per sec/ 186,000,miles/sec.

d) Light travels 9.5 Trillion km in a year = 1 light year– 1 Light year measures both distance &

time

Electromagnetic spectrum: (Review)

• Radio waves: – Longest wavelength:105 to 10 -1 meters– Lowest frequency: 103 to 109 Hertz– Used for communication & information transfer

• Microwaves: – Wavelength: 10 -1 to 10 -3 meters & Frequency: 109 to 1011

Hertz– Used for communication, Info. Transfer & cooking

• Infrared:– Wavelength: 10 -3 to 10 -6 meters & Frequency: 1011 to 1014

Hertz– Used for heat production & Thermography– “Seen” by some insects & animals

• Visible Light:– Wavelength: 10 -7 meters & Frequency: 1015 Hertz– Colors seen by human eyes

• Ultraviolet:– Wavelength: 10 -7 to 10 -9 meters & Frequency: 1015

to 1017 Hertz– “Seen” by some insects– Cause of tanning, sunburn, skin cancer– Degrades rubber & plastic materials (fades cloth &

paper)

• X – Rays:– Wavelength: 10 -9 to 10 -11 meters & Frequency: 1017

to 1019 Hertz– Bone scans, Information transfer

• Gamma Rays:– High level radiation (Very Dangerous)– Shortest wavelength: 10 -11 to 10 -15 Meters– Highest frequency : 1019 to 1023 Hertz

E. Telescopes1. We use the electromagnetic spectrum to

observe space2. Optical telescopes:

a) Produce magnified images of objectsb) Visible light is collected by mirrors or lenses

& focused c) There are two main types of telescopes

i. Optical Telescopesii. Radio Telescopes

F.Refracting Telescope

1. Light from an object passes through a convex objective lens and is bent to from an image on the focal point.

2. The images is then magnified by the eyepiece. 3. Limited in size4. Worlds refracting mirror is Yerkes Refracting

Telescopea) Just over a meter in diameter (distance

across)

Diagram of a Refracting Telescope

Focal PointConvex Lens Eyepiece

G. Reflecting telescopes1. Light passes trough the telescope housing to

a concave mirror2. Mirror reflects light to a flat mirror3. Flat mirror redirects light to a focal point4. Light passes through the focal point, to the

eyepiece5. Eyepiece magnifies image 6. Largest in the world = 10 meters wide

Diagram of a Reflecting Telescope

H. Optical Telescope Uses:1. Most “home” use telescopes are optical2. Used to see moon features & close planets3. Scientific optical telescopes are housed in observatories

a. Observatories have dome shaped roofs that open b. Observatories built on mountains or deserts, far away

from citiesi. Prevents city light interference & pollution blurringii. Decreases “down time” due to poor weather

c. Not all optical telescopes are housed in observatories

I. Radio telescopes:1. Designed to pick up radio waves emitted from

stars2. Usable in any weather

a. Radio waves concentrated by dish shaped bodyb. Concentrated waves directed to focal pointc. Focal point fixed with a receiverd. Receiver transmits information to computers

i. Detects objects deep in spaceii. Maps the Universeiii. Searches for intelligent life out in space

3. Largest in the world = 300 m wide dish

Radio Telescopes

J. Hubble Telescope (Reflecting telescope)1. Launched in 1990 by the space shuttle Discovery.2. Since Hubble did not have to view space through the

Earth’s atmosphere, it should have produced very clear images.

3. However there was a mistake in the largest mirror used in the Hubble Telescope.

4. Images were not as clear as expected. 5. December 1993 first set of repairs were fixed by

astronauts. 6. Has been repaired numerous times since.

a. Hubble Telescope

End of Day #2 Lecture!!

1. Homework Vocabulary Quiz Friday!!!2. Blended Schools Chapter 21

a. Homework/StudyGuides Folderi. Lecture Day #1 Worksheet due Fridayii. You will have time to work on this in class Wednesday

3. Video: All about Telescopes

21.2 Light PollutionA. Light pollution & stargazing

1. Night time sky from the citya. Hazy, glowing sky with a few bright stars

2. Night time sky from far away from citiesa. Crisp, black sky with many stars of different

brightness

B. The difference = Light Pollution1. City lights & bright moon light cover the dimmer

stars

C. Large US cities are reducing light pollution1. Low pressure sodium lights replacing mercury

vapor lightsa. Reduces glare, improves over all visibility, cheaper

to run

2. “Hooding” large light sources

Pgs: 591 - 593

Night View from Space

2 Points of ViewD. Right to have security lighting

1. Crime & Safety is a unilateral concerna. Lighting is a main tactic for preventionb. Property owners use lights to protect people &

property E. Right to Dark Sky Observation

1. Natural phenomena should be viewablea. Meteor showers are everyone’s right to seeb. Security lighting too bright, and drowns out your

viewF. Who’s right’s are more important (Your’s or Their’s)?

21.3 Artificial Satellites & Space Probes

A. The first steps into space1. Telescopes view objects from a distance2. Scientists want to get closer

B. Satellites: 1. Space exploration began in 19571957 (Sputnik I)

a) USSR placed Sputnik I in a low level orbit (visible from Earth)i. Orbited Earth for 3 monthsii. Caused major panic in the US iii. Began the “Space Race”

2. Satellites are any object that revolve (orbit) around a larger objecta) Orbit: curved path of satellites around a star,

planet, etc.

Pgs. 594 - 599

How Satellites stay in orbitC. Orbital Motion is a combination of two forces

1. Inertial motion: force moving the object in a straight line

2. Gravity: force pulling the object back toward Eartha. The forces are at right angles to each other resulting

in a curved pathb. Too much Inertia = satellite spirals away from Earthc. Too little Inertia = satellite spirals back to Earth

(decaying orbit)

Watch as theRope is cut

D. Modern Satellites

1. Today thousands of artificial satellites orbit the Earth2. Have many different functions

1. Military: “Spy” satellites observe & record images & communications

2. Communications: Transmit & relay telephone, radio, and T.V. signals

3. Weather: Monitor storms, winds, temperatures, etc.4. Scientific: Collect data from space & Earth (wide

range of uses)

E. Space Probes:1. Not all objects in space become satellites2. Scientists use space probes to gather

information also3. Space Probe: Electronic equipment designed to

gather information and transmit it back to Eartha. Travel through (and out of) the Solar Systemb. Carry cameras, radio transmitters & receivers, sensors,

etc.

F. The Voyagers1. Voyager 1 and Voyager 2

a. Launched in 1977b. Voyager 1 designed to fly by Jupiter & Saturnc. Voyager 2 designed to fly past Jupiter & Saturn to Uranus

& Neptuned. Both have left our immediate solar system and are still

transmitting today

Jupiter by Voyager 1

Saturn by Voyager 2

Neptune by Voyager 2

G.Galileo1. Galileo was a two phase probe sent to Jupiter2. Launched in 1989 it reached Jupiter in 19953. It then released a smaller probe that parachuted

through Jupiter’s atmosphere until crushed by the intense gravity

4. The small probe sent back info. about atmospheric temperature, pressure, and composition

5. Galileo studied Jupiter’s moons, rings, & magnetic field

Galileo’s View as it Approaches Jupiter

• http://www2.jpl.nasa.gov/galileo/countdown/impact.html

H. The Race to the Moon1. Sputnik I was the beginning of the “Space

Race” between the US and Soviet Union2. In 1961, Russian Cosmonaut Yuri A. Gagarin

became the first human into space3. President John F. Kennedy calls for the US to be

the first to land on the moon4. The US had several programs to reach the goal5. Each program was designed to reach a step to

the moon

I. Project Mercury1. Goal: Orbit a craft around the Earth & return it

safelya. Gave valuable information about space travelb. United States program to reach the moon began with

Project Mercury.c. Consisted of 9 missions

d. May 5, 1961: Alan B. Shepard = First American in spacei. 15 minutes

d. 1962: John Glenn = First American to orbit Earthd. 4 hours, 55 minutes

J. Project Gemini1. Goal: Team of two will spend 10 days in space2. Consisted of 10 missions3. Learned skills needed for the trip to the moon4. One team docked with another ship while in

space5. During the ongoing Gemini project, several

probes were sent to the moona. Ranger: Proved reaching the moon was possibleb. Surveyor: Proved a lunar landing was possiblec. Orbiter: Took pictures of the moon’s surface

Project Apollo• Series of missions to reach, land on & explore the

moon• Apollo 11: first to reach the moon (July 20, 1969)

– Neil Armstrong: first person to walk on the moon• “One small step for man, One giant leap for

mankind”– Edwin “Buzz” Aldrin joined Armstrong exploring for

2 hours– Michael Collins remained in the Command Module

(orbiting moon)• 5 other Apollo Missions also landed on the moon

– All total more than 2000 samples of lunar rocks & soil was collected

• The program ended in 1972

The Apollo Rocket• The Apollo program use

multistage rockets – Only a small part of the rocket

returned to Earth– Only the Lunar module descended to

the moon– Service module and command

module remained in lunar orbit– The Command module returned to

Earth

Images of Apollo

Current Space Travel

• Currently many nations work together in space travel

• The International Space Station:– A cooperative effort between many countries to

build an extraterrestrial habitat used for research. Started in 1998 and the first person inhabited it on 2000. There have been people there ever since 2000.

• Missions to Mars:– Several countries are working towards a joint

mission– Possibilities of a Martian base are also being

considered

INTERNATIONAL SPACE STATION

21.4 The Space Shuttle & the Future• The Reusable Spacecraft

– NASA (National Aeronautics & Space Administration) realizes Multistage rockets are expensive & wasteful

– Designed the Space Shuttle: • A reusable craft capable of carrying

people, satellites, and experiments• Made up of 3 main parts

– Orbiter: Plane like ship– External fuel tank: Largest tank filled

with liquid Oxygen & Hydrogen– 2 solid rocket boosters: Produces

thrust required to launch

Pgs. 604 - 608

Night Launch

Shuttle Endeavor launch on March 10th, 2008 @ night

LANDING

PART OF THE ORBITER

Shuttle Launch• Upon Launch the solid rocket boosters fire

producing lift– At 45 km (27 miles), they are depleted & eject

(parachuting back to Earth)– Recovered & Reused

• Shuttle flies on fuel from the External Tank– Once it is empty it is ejected (crashing into the

Ocean)– External Tanks are not reused (scrapped &

recycled)

• Once in space the shuttle orbits the Earth– Experiments conducted, Satellites deployed, etc.– Upon completion of mission the Orbiter returns– Glides into a runway, landing like an Airplane

The Orbiter

Space Stations

• Space Ships only limited resources, & cannot stay in space for long periods of time

• Space stations are massive complexes that allow humans to stay in space for extended periods of time– Provides living quarters, work & exercise areas– Carries all equipment & support systems needed

• Sky Lab: US Space Station launched in 1973– Crews stationed for 84 day tours– Purpose: Perform experiments on effects of living

in space– Scrapped in 1979 (Placed in decaying orbit &

burned up) • Mir: Russian space station

– Cosmonauts stay for 438 days (current record)

Cooperation in Space• Countries realize that pooling resources =

less expense• 1995: US & Russia begin working together

on projects• Americans now travel in Russian rockets &

Russians travel in the Space Shuttle• The Atlantis was the first shuttle to dock

with Mir• The International Space Station

– Project began in 1997 (on going)– A dozen nations are cooperating to build the

station– Main components built on Earth & transported

into space– The components will be assembled in space

International Space Station• Three Phase Project

– Phase 1: Shuttle & Mir docking missions (Stockpiling of supplies)

– Phase 2: Assembly of main body (Bilateral Station Alpha)

– Phase 3: Crews will permanently inhabit & operate station

• NASA will keep astronauts on the station for several months at a time

• Producing materials to be used on Earth• Potentially begin building space ships for trips

to the Moon or Mars

Disasters of the Space Program• 1986 – Space Shuttle

Challenger exploded killing all 7 astronauts on board. Christa McAuliffe was to be the first teacher in space.

• The shuttle exploded because of a fuel leak that reached the engines

COLUMBIA• In 2003 upon re-entry into our atmosphere the Space Shuttle ColumbiaColumbia exploded, killing all 7 astronauts on board.

• When the Columbia lifted off so foam damaged the heat tiles. So when reentry happened the heat of the atmosphere caused the orbiter to explode.

APOLLO 13

• Apollo 13 was the third manned lunar-landing mission, part of Project Apollo under NASA in the United States. It launched on April 11, 1970. Two days after the launch, the Apollo spacecraft was crippled by an explosion, caused by a fault in the oxygen tank. The explosion damaged the Service Module, resulting in a loss of oxygen and electrical power. The crew used the Lunar Module as a “lifeboat”. They of course made it back to earth safely.

Apollo 13 as it looked upon landing in the ocean

Future Space Missions