Exam 6: Formation of Planetary Systems: Our Solar System and Beyond

Which of the following methods has led to the most discoveries of massive planets orbiting near their parent stars?

Based on our theory of how our own solar system formed, we would expect that other solar systems would be quite common.

The terrestrial planets in our solar system are ________.

Which of the following has not been detected around other stars in the Galaxy?

In the searches so far, only about 1 in 10 stars show evidence for planets around them.

According to our present theory of solar system formation, which of the following lists the major ingredients of the solar nebula in order from the most abundant to the least abundant?

Predictions for Extra-solar Planets: What predictions does the solar nebula theory make regarding possible planetary systems surrounding other stars? Discuss at least two such predictions that have been strongly confirmed by observations. Explain how the detection of "hot Jupiter" extrasolar planets seemed to be a striking inconsistency with the solar nebula theory. Do you think astronomers were justified in modifying the solar nebula theory in the face of such evidence as opposed to discarding the theory altogether?

Impacts were extremely common in the young solar system but are less common today.

According to our present theory of solar system formation, how did Earth end up with enough water to make oceans?

What kind of material in the solar nebula could remain solid at temperatures as high as 1,500 K, such as existed in the inner regions of the nebula?

Which of the following statements about the recently-discovered object Eris is not true?

How do we know the mass of Neptune?

When we say that jovian planets contain significant amounts of hydrogen compounds, we mean all the following chemicals except ________.

You have observed the wobble in the velocity curves of two otherwise identical stars. Star A has a period of 6 months and Star B has a period of 1 year. What can you say about these stars?

What do we mean by the frost line when we discuss the formation of planets in the solar nebula?

You are observing the wobble of a star caused by the orbit of a planet around that star. Which property of this system listed below most significantly affects the period of that wobble?

Which planet search technique is currently best suited to finding Earth-like planets?

Which of the following is a consequence of the discovery of hot Jupiters for the nebular theory of solar system formation?

What percentage of the solar nebula's mass consisted of rocky material?

The Solar Nebula as a Scientific Theory: You are describing the solar nebula theory to a friend. You point out that it provides an explanation for the regular motion in our solar system, the division of the planets into terrestrial and jovian types, and an explanation for the origin and nature of comets and asteroids. Your friend agrees that this is all very nice, but that it seems that the solar nebula theory fails the basic criteria for a scientific theory, to make predictions about the natural world that can be observationally tested. In her opinion, all the solar nebula theory does is explain known facts, albeit in a compelling and economical way. How would you answer your friend and make the case that the solar nebula theory is indeed a scientific theory that has passed many observational tests? Can you think of any predictions that the solar nebula theory has made that were confirmed only within the last decade or so?