Ch 22 Exploring Space Radiation from Space Electromagnetic Radiation Stars give off different wavelengths of light that make up the spectrum. Stars give.

Ch 22Ch 22Exploring Exploring

SpaceSpace

Radiation from Space Radiation from Space

Electromagnetic RadiationElectromagnetic Radiation

• Stars give off different wavelengths of Stars give off different wavelengths of light that make up the spectrum.light that make up the spectrum.

• Light travels as a transverse wave.Light travels as a transverse wave.

Light is the fastest thing in the Universe, traveling at 299,792,458 meters per second.

Photons of light travel in waves just 380 to 750 nanometers (millionths of a millimeter) long.

• Transverse waves have crests and Transverse waves have crests and troughs.troughs.

• The distance from one crest to another The distance from one crest to another is called the wavelength.is called the wavelength.

• The frequency is the number of wave The frequency is the number of wave crests that pass a certain point over crests that pass a certain point over time.time.

crest wavelength

trough

Light rays always travel in straight lines.

• Radio waves (longest)Radio waves (longest)• MicrowavesMicrowaves• InfraredInfrared• Visible (R.O.Y.G.B.I.V.)Visible (R.O.Y.G.B.I.V.)• UltravioletUltraviolet• X-RaysX-Rays• Gamma Rays (shortest)Gamma Rays (shortest)

Light rays change direction as they pass from one material to another. This is called refraction

The longest light waves you can see are red, and the shortest are violet

• Speed of light ≈ 300,000 km/sSpeed of light ≈ 300,000 km/s

• All forms of light travel at the same All forms of light travel at the same speed.speed.

• A Light Year (ly) is the distance it A Light Year (ly) is the distance it takes light to travel in takes light to travel in one yearone year..

• About 9.46 trillion km/yearAbout 9.46 trillion km/year

According to Einstein's theory of special relativity objects gain mass as they speed up, and that speeding up requires energy. The more mass, the more energy is required. By the time an object reached the speed of light, Einstein calculated, its mass would be infinite, and so would the amount of energy required to increase its speed. To go beyond the infinite is impossible.

Optical TelescopesOptical Telescopes• Telescopes that use light to produce Telescopes that use light to produce

magnified images of objects.magnified images of objects.

Refracting TelescopesRefracting Telescopes RefractionRefraction is the bending of light is the bending of light

as it passes through different as it passes through different materials.materials.

A convex lens is used to bend the A convex lens is used to bend the light and is magnified.light and is magnified.

Galileo built the 1Galileo built the 1stst refractor. refractor.

Galileo had to leave the university because he ran out of money but his brilliant treatises on physical laws earned him a series of teaching posts at Italian universities

One day in 1608 a Dutch spectacle maker named Lippershey held a lens in each hand and peered through both at once, accidentally discovering that 2 lenses placed in line would magnify an image. He mounted a lens at each end of a tube and invented the telescope.

Refraction & Refracting TelescopesRefraction & Refracting Telescopes

Reflecting TelescopesReflecting Telescopes Telescopes that use concave Telescopes that use concave

mirrors to reflect the light from an mirrors to reflect the light from an object to a focal point.object to a focal point.

All things being equal, the telescope that is easiest to set up is the one that'll get used by amateur astronomers. 

Forget about magnification when buying a telescope. The size of the lens or mirror is WAYYYYY more important!

Hubble Space TelescopeHubble Space Telescope Launched in 1990Launched in 1990 Placed in high Earth orbit, free of Placed in high Earth orbit, free of

atmospheric distortion.atmospheric distortion.

You are not going to see anything remotely like what you see on the NASA websites or on calendars and posters through a telescope at home. Those images were taken by multi-million dollar spacecraft that were processed by a team of scientists whose job is to make pretty pictures. With the exception of the planets and the Orion Nebula, you're going to see a smudge of light through even the largest amateur telescopes.

Radio TelescopesRadio Telescopes Used to map the UniverseUsed to map the Universe Detects objectsDetects objects Search for signs of intelligent life Search for signs of intelligent life

on other planetson other planets

Early Space Missions Early Space Missions

Newton’s Laws of MotionNewton’s Laws of Motion Law of InertiaLaw of Inertia

An object in motion will stay in An object in motion will stay in motion, an object at rest will stay at motion, an object at rest will stay at rest.rest.

An outside force will change the An outside force will change the inertia.inertia.

To leave orbit, spacecraft must move faster than 11 km/s

Inertia

Law of Acceleration (Force)Law of Acceleration (Force) An accelerated mass creates An accelerated mass creates a a

force.force.

F = maF = ma

Newton (N) = kg Newton (N) = kg •• m/s m/s22

Law of Action/ReactionLaw of Action/Reaction For every action (force), there is an For every action (force), there is an

equal action in the opposite equal action in the opposite direction.direction.

Reaction

Action

RocketryRocketrySolid Fueled RocketsSolid Fueled Rockets

Solid fueled rockets were invented Solid fueled rockets were invented by the Chinese.by the Chinese.

Difficult to controlDifficult to control

Liquid Fueled RocketsLiquid Fueled Rockets Dr. Robert Goddard successfully Dr. Robert Goddard successfully

launched the first liquid fueled launched the first liquid fueled rocket in 1926.rocket in 1926.

Rocketry is based on Newton’s 3Rocketry is based on Newton’s 3rdrd Law of MotionLaw of Motion

Action Reaction

• Notable Rockets:Notable Rockets: German V-2 Rocket of WWIIGerman V-2 Rocket of WWII USA Saturn V Rocket for the USA Saturn V Rocket for the Apollo Apollo

Moon missions.Moon missions.

Only one Gemini capsule was given a name , the first capsule was called Molly Brown by Astronaut Gus Grissom.

Artificial SatellitesArtificial Satellites

• Satellites are objects that orbit around Satellites are objects that orbit around another large object.another large object.

• Sputnik ISputnik I was the 1 was the 1stst satellite to orbit satellite to orbit Earth (Russia, 1957)Earth (Russia, 1957)

• Hundreds of satellites orbit the Earth Hundreds of satellites orbit the Earth today (weather, GPS, communications, today (weather, GPS, communications, etc.)etc.)

• Satellites maintain their orbit as a result of Satellites maintain their orbit as a result of gravity & inertia counteracting each other.gravity & inertia counteracting each other.

• ““Falling around Earth”Falling around Earth”

InertiaInertia

GravityGravityResulting OrbitResulting Orbit

Space ProbesSpace Probes

• Satellites with instruments that travel Satellites with instruments that travel away from the Earth.away from the Earth.

• Some orbit distant objects while Some orbit distant objects while others land on surfaces.others land on surfaces.

Galileo studied Europa (one of 61 moons of Jupiter), Europa may have an ocean and heat under it’s ice. Maybe life!

• Notable Space Probes:Notable Space Probes: Mars:Mars:

• Vikings IVikings I & & IIII (1974) (1974)

• MarinerMariner Program Program

(Mercury, Venus also)(Mercury, Venus also)

• Mars PathfinderMars Pathfinder

w/ rover (1998)w/ rover (1998)

• SpiritSpirit & & OpportunityOpportunity

(2004)(2004)

Venus:Venus: • Venera Venera program program

(1960s-1970s)(1960s-1970s)• MagellanMagellan Program Program

Outer Planets & ObjectsOuter Planets & Objects• Voyagers I & IIVoyagers I & II • GalileoGalileo (Jupiter) (Jupiter)• Cassini-HuygensCassini-Huygens

(Saturn & Titan)(Saturn & Titan)• New HorizonsNew Horizons (Pluto) (Pluto)• StardustStardust probe (comet) probe (comet)• NEAR-ShoemakerNEAR-Shoemaker (asteroids) (asteroids)

Manned Space MissionsManned Space Missions

Space Shuttle ProgramSpace Shuttle Program

• A set of reusable, Earth orbiting A set of reusable, Earth orbiting spacecrafts by NASA.spacecrafts by NASA.

• First launch in 1981 (First launch in 1981 (ColumbiaColumbia))

• Other space shuttles include:Other space shuttles include: ChallengerChallenger DiscoveryDiscovery AtlantisAtlantis EndeavourEndeavour

Yuri Gagarin was the first person in space! Alan Shepard was the first American in space. Neil Armstrong was the first person on the moon. Who was second?

ChallengerChallenger Disaster Disaster Shuttle blew apart 73 seconds into Shuttle blew apart 73 seconds into its its

mission. (January 1986)mission. (January 1986)

ColumbiaColumbia Disaster Disaster Shuttle broke apart during re-entry to the Shuttle broke apart during re-entry to the

Earth’s atmosphere 16 minutes before Earth’s atmosphere 16 minutes before landing (February 2003)landing (February 2003)

• The shuttles will be decommissioned in The shuttles will be decommissioned in 2010 to prepare for missions to the moon.2010 to prepare for missions to the moon.

• (Endeavour(Endeavour was originally scheduled to be decommissioned in was originally scheduled to be decommissioned in 2010 after 18 years of service, but on July 1, 2010, NASA released 2010 after 18 years of service, but on July 1, 2010, NASA released a statement saying the shuttle a statement saying the shuttle EndeavourEndeavour mission was mission was rescheduled for February 27, 2011, instead of late November, rescheduled for February 27, 2011, instead of late November, 2010.)2010.)[[

Space StationsSpace Stations

U.S. U.S. SkylabSkylab (1973-1979) (1973-1979) U.S. only solo attempt at building a space U.S. only solo attempt at building a space

station.station. Study the effects Study the effects of of

living & working living & working in in space.space.

Crashed into the Crashed into the Indian Ocean in Indian Ocean in 1979 1979

MirMir (1986-2001) (1986-2001) Russia’s 7Russia’s 7thth space station space station Only supposed to last 5 years.Only supposed to last 5 years. De-orbited in 2001 into the Pacific Ocean De-orbited in 2001 into the Pacific Ocean

International Space StationInternational Space Station (ISS) (ISS) Construction began in space in 1998Construction began in space in 1998 16 countries involved16 countries involved Support 7 crew members for 3-6 months Support 7 crew members for 3-6 months

when finished.when finished.