Lesson 1: Observing the Night Sky

The apparent daily motion of the sun, moon, and stars from east to west is caused by?

The earths rotation

On March 21 the sun is directly above which location?

The equator

What is the optimum magnification for an eight inch telescope?

(8 x 15) = 120x

How long is Earth's rotation period?

24 hours, or one day

How many light years are in one parsec?

3.26 ly

How fast do radio waves travel?

300,000 km/s

How long is Earth's revolution period?

365 and 1/4 days or one year.

What is a CCD

A charge-coupled device

The distance from the earth to the sun is called?

Astronomical unit

What are the three practical units of measurement for describing the distance from Earth to Proxima Centauri (the nearest star after the sun)?

Astronomical units, light years, and parsecs.

Issac Newton made what important discovery involving concave mirrors?

They cause the light rays to converge to a focus point.

What is a photon?

Tiny packet or bundle of energy.

What term refers to how clear the sky is?

Transparency.

T/F: All electro magnetic waves travel at 300,000 km/sec in a vacuum.

True

T/F: Light changes direction when it changes mediums.

True

T/F: the amount of light collected by a telescope is proportional to the area of its aperture.

True

T/F: light leaving the earth would take a little more than one second to reach the moon, 400,000 km away.

True because light travels at 300,000 km/s

T/F: Reflecting telescopes often suffer from spherical aberration.

True.

Which electromagnetic waves has the most energy?

Ultraviolet

What is the best way to obtain astronomical data?

Use a telescope in space.

What causes electromagnetic radiation?

Vibrating electrons in an atom.

Why does Earth have four seasons?

Earth's axis is tilted 23.5 degrees from its plane of orbit around the sun.

T/F: the number of times you will orbit the Sun in your lifetime will be the same amount as the number of DAYS in your life.

False

T/F: The biggest telescope in use today are refracting telescopes.

False- Reflecting

T/F: the Hubble Space Telescope gives us much better images than Earth-based telescopes because it is much larger than Earth-based telescopes.

False- it's better because the light reaching it does not have to travel through Earths atmosphere.

Who was the first person to realize that mirrors could be used to construct a telescope?

Isaac Newton

Why can the Hubble Space Telescope (HST) produce better photographs of space than telescopes on earth?

Light does not get distorted by the atmosphere.

Polaris

Name of the North Star

Earth's axis point points directly to...

Polaris (North Star)

What is the correct order of the electromagnetic spectrum?

Radio, infrared, visible light, ultraviolet, X-rays, gamma.

What are the two types of telescopes?

Refracting and reflecting

Distance = ...?

Speed x time