FRS 126: Imagining Other Earths

David Spergel  113 Peyton Hall 8-3589

Student email exploder: FRS126_S2013@Princeton.EDU

MW 3:00-4:20 PM Blair Tower


Over the past two decades, astronomers have discovered more than 1000 planets around nearby stars. Most of these planets have been discovered in the past two years! In this seminar, we will explore how these planets are being discovered, the prospects for characterizing these planets, and explore the properties of these new worlds. The goal of the course is to introduce students to the new field of exoplanets and to use exoplanets as an opportunity to learn “back of the envelope” physics and astronomy.

Reading List:

o   James Kasting, How to Find a Habitable Planet (HP)

o   L. Weinstein and J.A. Adam, Guesstimation (G)

o   Neil F Comins, What if the Earth had Two Moons? (E2M)

o   Useful websites:








o   Class Participation 25%

o   Final Paper + Presentation 35%

o   First Paper + Presentation: 15%

o   Homeworks: 25%


o   First paper + presentation: prepare a ten minute presentation to the NAS decadal survey 2020 review advocating a new mission to characterize extrasolar planets; and write a five page supporting paper describing the mission and its scientific capabilities.

o   Final paper + presentation: Invent a planet and write a 10 page paper describing its properties and habitability.

o   Problem sets (first problem set available after first lecture)

o   Attendance



Schedule (subject to change):

How We Find Planets?

o   Feb 4: Introductions; Overview of Extrasolar Planets; Introduction to Estimation

o   Guest Lecturer: Jim Green (NASA HQ)

o   Reading: Guestimation (G) Chapter 1-3; How to Find a Habitable Planet (HP), Chapter 1

o   Homework 1 Available


o   Feb 6   Radial Velocity Searches for Planets

o   Reading: G: Chapter 6; HP: Chapter 11

o   Feb 11 Kepler Mission

o   Guest Lecturer: Lucianne Walkowicz (Kepler Science Team)

o   Reading:  HP Chapter 12

o   Homework 2 Available


o   Feb 13  Imaging Other Planets

o   Reading HP Chapter 13

o   Homework 1 Due

o   Feb 18 Visit to High Contrast Imaging Lab

Stars and Planetary Atmospheres


o   Feb 20 Stars I  and GR and Microlensing

o   Homework 2 due

o   Homework 3 available

o   Feb 25  Stars II

o   G Chap 8 +9

o   Feb 27 Planetary Atmospheres I:

o    Homework 3 due

o   Mar 4 Stellar and planetary spectra

o   What if the Earth Had Two Moons (E2M)? Chapter 6

o   Homework 4 available

o   Mar 6 Planetary Atmospheres  [David Spiegel- guest lecture]

o   HP Chapter 14 + 15

Student Presentations

o   There is a list of possible topics at

o   Mar 11 Student Presentations I

o   Mar 13 Student Presentations II


o   Mar 15 8 PM John Grotinzger, leader of the Curiosity Rover, University Public Lecture



Mar 18/20 Midterm Break


Rocky Planets

o   Mar 25 Tides and Moons:

o               E2M: Chapter 1+2

Mar 27 Formation History of the Earth and the Origin of Water

            Sample project: Comets

o   HP: Chap 2, 5

o   E2M: Chap 3

o   Homework 4 Due

o   Apr 3 Mars

o   HP Chap 6

o   Apr 8 Venus and Europa

o   HP Chap 7

Life: Earth and Beyond

o   Apr 10:  Origin of Life + Other Biologies

o   Apr 15 Evolution

o   Apr 17 Extremophiles

o   Apr 22 Evolution and Sex + Origin of Complexity

o   HP Chap 8 + 9


o   Apr 24: Our Galaxy + Habitable Zones

o   E2M Chap 6

o   Homework 3 Due

o   Apr 29: No Lecture

o   May 1: History of the Universe

o   E2M Chap 5

Final Presentations

o   May 6 Student Presentations I

o   May  8 Student Presentations II

o   May 9 Trip to Goddard Space Flight Center

o   May 10 Student Presentations III

o   May 14 Final Paper Due