Sect 8.1

6th Grade Science

Chapter 8 Exploring

Space

Notes Section 8.1

The Orion Nebula

• What is radiation?• Radiation is energy that is transmitted from one

place to another by electromagnetic waves. • What is the electromagnetic spectrum?• The electromagnetic spectrum ranges from

gamma rays with a wavelength of 1.0x10-11 m to radio waves with a wavelength of 1.0x106 m

Key Questions 1

The Tadpole Galaxy

• How fast do all electromagnetic waves travel?• All electromagnetic waves travel at 3.0x108 m/s.• How do refracting and reflecting telescopes work?• Refracting telescopes use convex lenses which

are curved outward. Reflecting telescopes uses a curved mirror to gather light onto a eyepiece lens.

Key Questions 2

The Sombrero Galaxy

•Light travels from the sun to the Earth in 9 minutes.

•Light can travel around the Earth more than 7 times in one second.

• Who first turned a telescope to the stars?• Galileo Galilei first turned a telescope to the

stars in the 1600’s.• Why is the Hubble located outside the Earth’s

atmosphere?• The Hubble is located outside Earth’s

atmosphere to avoid interference caused by Earth’s atmosphere.

Key Questions 3

Galileo Galilei (1564-1642) invented the microscope and the thermometer. He improved the telescope and made observation about the sun and the planets

A mountain of dust and gas rising in the Carina Nebula. The top of a three-light-year tall pillar of cool hydrogen is being worn away by the radiation of nearby stars

The Crab Nebula is a supernova remnant, all that remains of a tremendous stellar explosion. Observers in China and Japan recorded the supernova nearly 1,000 years ago, in 1054.

Supernova 1987A, has continued to fascinate astronomers with its spectacular light show.

The Helix Nebula, located 690 light-years away, is one of the closest planetary nebulas to Earth. One possible scenario for the Helix's complex structure is that the dying star has a companion star.

NGC 7009 has a bright central star at the center of a dark cavity bounded by a football-shaped rim of dense, blue and red gas.

Horse Head Nebula

About 1,500 galaxies are visible in this deep view of the universe, taken by allowing the Hubble Space Telescope to stare at the same tiny patch of sky for 10 consecutive days in 1995. The image covers an area of sky only about width of a dime viewed from 25 yards away.

• What are adaptive optics?• Adaptive optics is a telescope with a computer

that corrects the lenses for changes in the atmosphere.

• What are radio telescopes?• Radio telescopes are used to study radio waves

that pass freely through Earth’s atmosphere.

Key Questions 4

1. Identify one advantage of radio telescopes over optical telescopes.

2. If red light has a longer wavelength than blue light, which has the greater frequency

3. Explain the difference between sound waves and radio waves.4. Describe how adaptive optics in a telescope help solve problems

caused by atmospheric turbulence.5. It takes light from the closest star to earth (other than our sun)

about four years to reach earth. If intelligent life were on a planet circling that star, how long would it take for scientists on Earth to send them a radio transmission and for the scientists to receive their reply?

Questions Section 8.1