Studying SpaceStudying SpaceChapter 26 NotesChapter 26 Notes

StandardsStandards

2b Students know galaxies are made 2b Students know galaxies are made of billions of stars and comprise most of billions of stars and comprise most of the visible mass in the universe.of the visible mass in the universe.

2d. Students know that stars differ in 2d. Students know that stars differ in their life cycles, and visual, radio, and their life cycles, and visual, radio, and x-ray telescopes may be used to x-ray telescopes may be used to collect data that reveal those collect data that reveal those differences.differences.

The Value of AstronomyThe Value of Astronomy

Studying astronomy leads to the discovery Studying astronomy leads to the discovery of planets, stars, black holes, formation of of planets, stars, black holes, formation of our earthour earth

Benefits to humans may include finding Benefits to humans may include finding new sources of energynew sources of energy

May help protect us from disasters such May help protect us from disasters such as collisions between Earth and Asteroidsas collisions between Earth and Asteroids

Characteristics of the UniverseCharacteristics of the Universe

Universe began to form about 14-15 billion Universe began to form about 14-15 billion years ago with “The Big Bang” and years ago with “The Big Bang” and continues to expand.continues to expand.

The Universe is very large and objects are The Universe is very large and objects are far apart.far apart.

The nearest part of the universe to Earth is The nearest part of the universe to Earth is the our Solar System, the sun, the moon, the our Solar System, the sun, the moon, planets and asteroids.planets and asteroids.

Measuring Distances in the Measuring Distances in the UniverseUniverse

Since the Universe is so big we can not use our Since the Universe is so big we can not use our system of measurement to determine distancessystem of measurement to determine distances

To measure distances in the Solar System we To measure distances in the Solar System we use the distance between the Earth and the Sun. use the distance between the Earth and the Sun. This is an “Astronomical Unit” or AU = This is an “Astronomical Unit” or AU = 149,597,870.691km 149,597,870.691km

Speed of Light = 9.46 x 10 How far light travels Speed of Light = 9.46 x 10 How far light travels in a year. The closest star (besides the sun) is in a year. The closest star (besides the sun) is 4.22 light years away from Earth.4.22 light years away from Earth.

Observing SpaceObserving Space

Stars emit light which allows us to observe the Stars emit light which allows us to observe the night sky. (Planets do not emit light)night sky. (Planets do not emit light)

Humans can only see visible light. But some Humans can only see visible light. But some objects emit light through radiation, x-ray or objects emit light through radiation, x-ray or radio waves. The “Electromagnetic Spectrum” radio waves. The “Electromagnetic Spectrum” includes all form of light.includes all form of light.

Different forms of light travels at different Different forms of light travels at different speeds/wavelengths. Astronomers use special speeds/wavelengths. Astronomers use special instruments to detect electromagnetic radiation.instruments to detect electromagnetic radiation.

Electromagnetic SpectrumElectromagnetic Spectrum

TelescopesTelescopes

In 1569 GalileoIn 1569 Galileo

used two lenses toused two lenses to

make objectsmake objects

appear closer. appear closer.

Types of TelescopesTypes of Telescopes

Optical Telescopes collect only visible lightOptical Telescopes collect only visible lightReflecting telescopes used a curved mirror Reflecting telescopes used a curved mirror

to gather and focus light from distant to gather and focus light from distant objectsobjects

Refracting TelescopeRefracting Telescope

Bends light to gatherBends light to gather

imagesimages

Hubble Space TelescopeHubble Space Telescope

CollectsCollects

ElectroElectro

Magnetic radiationMagnetic radiation

From objectsFrom objects

In spaceIn space

Human Space ExplorationHuman Space Exploration

ApolloApollo

AstronautsAstronauts