If the material for life were introduced from space after the Earth formed, a major carrier would have been:
A) the solar wind.
B) tektites from the Moon.
C) comet impacts.
D) encounters with other solar systems.
E) iron meteorites.
Question 2Under which circumstances can you be sure that the thermal pressure within a gas cloud is increasing?
A) The cloud's temperature and density are both increasing.
B) The cloud's temperature is increasing and its density is decreasing.
C) The cloud's temperature and density are both decreasing.
D) The cloud's temperature is decreasing and its density is increasing.
E) It is impossible to say.
Question 3Halley's comet is named after the English scientist Edmund Halley (1656-1742 ) because
A) he was first person to see it when it passed near Earth in 1682.
B) the discoverers named it for him in honor of his financial support.
C) he was the most famous astronomer alive in England during its appearance in 1758.
D) he calculated its orbit and predicted the year in which it would next be seen.
Question 4Planets do not move on a straight line. According to Newton's First Law of Motion, that means that there must be an outside ________ acting on them.
Fill in the blank(s) with correct word
Question 5Discuss the relationship between young stars and the interstellar medium.
What will be an ideal response?
Question 6You observe a spiral galaxy with a large central bulge and tightly wrapped arms. It would be classified an:
A) Sc.
B) Sb.
C) Sa.
D) SO.
E) E7.
Question 7Why does Mars appear red from Earth's surface?
What will be an ideal response?