Homework 12 – Astronomy

SCNC 101

Due: 12/07/05 (Wednesday)

On a separate sheet of paper, answer the following questions in complete sentences.

The Moon

(1)Is the far side of the Moon (the side that can never be seen from Earth) the same as the dark side of the Moon? Explain.

(2)(a) During what phase of the Moon can a lunar eclipse occur?

(b)During what phase of the Moon can a solar eclipse occur?

(c)Why doesn’t a solar eclipse occur every time the Moon is in this phase?

(3)Complete the following chart:

Phase / % of Disc Illuminated / Left or Right side illuminated / Time Moon appears overhead
New Moon
Full Moon
1st Quarter
3rd Quarter
Waxing Gibbous
Waning Gibbous
Waxing Crescent
Waning Crescent

Comets and Asteroids

(4)What are two differences and two similarities between comets and asteroids?

(5)Does a comet always have a tail? Explain.

(6)(a) Have large objects impacted the Earth in the past? Explain.

(b) How serious a threat is another large impact? Explain.

Inner Planets

(7)Explain why Mercury and the Moon have no atmosphere.

(8)What evidence supports the theory that Mercury and the Earth have molten cores?

(9)(a) At first glance, why would you expect Mercury to be the hottest planet?

(b)Explain what causes Venus to be hotter than Mercury?

(10)For Mercury, Venus, Earth, the Moon, and Mars, answer the following questions:

(a)Is there evidence that liquid water ever existed on the surface? Explain.

(b)Are the surfaces young or old? Explain using the concept of crater dating.

(11)What evidence supports the idea that hot-spot volcanism has occurred on Venus, Earth, and Mars?

Outer Planets

(12)What would happen if you tried to land a spacecraft on Jupiter?

(13)Explain why Jupiter has stripes.

(14)What is the Great Red Spot on Jupiter?

(15)Saturn’s rings are not giant hoops of rock. What are they made out of?

The Sun & Stars

(16)How do we know what the Sun is composed of?

(17)(a) What is differential rotation?

(b)Does the Earth experience differential rotation? Why or why not?

(c)What effect does differential rotation have on the Sun’s magnetic field?

(18)Explain why the Sun shines.

(19)(a) Which has a larger surface temperature, a red star or a blue star? Explain.

(b)Which has a longer lifespan, a main sequence red star or a blue star? Explain.

(c)Which has a larger diameter, a main sequence red star or a blue star? Explain.

(d)Which are more common, red stars or blue stars? Explain.