Studying Space Chapter 26 Notes Standards 2b Students know galaxies are made of billions of stars and comprise most of the visible mass in the universe. 2d. Students know that stars differ in their life cycles, and visual, radio, and x-ray telescopes may be used to collect data that reveal those differences.

The Value of Astronomy Studying astronomy leads to the discovery of planets, stars, black holes, formation of our earth Studying astronomy leads to the discovery of planets, stars, black holes, formation of our earth Benefits to humans may include finding new sources of energy Benefits to humans may include finding new sources of energy May help protect us from disasters such as collisions between Earth and Asteroids May help protect us from disasters such as collisions between Earth and Asteroids

Characteristics of the Universe Universe began to form about billion years ago with “The Big Bang” and continues to expand. Universe began to form about billion years ago with “The Big Bang” and continues to expand. The Universe is very large and objects are far apart. The Universe is very large and objects are far apart. The nearest part of the universe to Earth is the our Solar System, the sun, the moon, planets and asteroids. The nearest part of the universe to Earth is the our Solar System, the sun, the moon, planets and asteroids.

Measuring Distances in the Universe Since the Universe is so big we can not use our system of measurement to determine distances Since the Universe is so big we can not use our system of measurement to determine distances To measure distances in the Solar System we use the distance between the Earth and the Sun. This is an “Astronomical Unit” or AU = 149,597, km To measure distances in the Solar System we use the distance between the Earth and the Sun. This is an “Astronomical Unit” or AU = 149,597, km Speed of Light = 9.46 x 10 How far light travels in a year. The closest star (besides the sun) is 4.22 light years away from Earth. Speed of Light = 9.46 x 10 How far light travels in a year. The closest star (besides the sun) is 4.22 light years away from Earth.

Observing Space Stars emit light which allows us to observe the night sky. (Planets do not emit light) Stars emit light which allows us to observe the night sky. (Planets do not emit light) Humans can only see visible light. But some objects emit light through radiation, x-ray or radio waves. The “Electromagnetic Spectrum” includes all form of light. Humans can only see visible light. But some objects emit light through radiation, x-ray or radio waves. The “Electromagnetic Spectrum” includes all form of light. Different forms of light travels at different speeds/wavelengths. Astronomers use special instruments to detect electromagnetic radiation. Different forms of light travels at different speeds/wavelengths. Astronomers use special instruments to detect electromagnetic radiation.

Electromagnetic Spectrum

Telescopes In 1569 Galileo In 1569 Galileo used two lenses to make objects appear closer.

Types of Telescopes Optical Telescopes collect only visible light Optical Telescopes collect only visible light Reflecting telescopes used a curved mirror to gather and focus light from distant objects Reflecting telescopes used a curved mirror to gather and focus light from distant objects

Refracting Telescope Bends light to gather Bends light to gatherimages

Hubble Space Telescope CollectsElectro Magnetic radiation From objects In space

Human Space Exploration Apollo ApolloAstronauts