ASTR220 Collisions in Space

(Spring 2003; Reynolds)

Prof: Chris Reynolds

Phone: (301)405-2682

E-mail: chris@astro.umd.edu

Office: CSS 1243

Office hours: Tuesday 1.30-2.30pm, or by appointment

Textbook: Night Comes to the Cretaceous by James Powell

Course description

Astronomy 220 is an introductory course in astronomy for non-science majors. This course satisfies the CORE distributive studies requirement for a non-laboratory physical science course. Since this is a CORE course we will focus on active learning, emphasize critical thinking, and concentrate on written expression.

As the course title implies, we will examine the role of collisions in the formation and development of the universe. Collisions of comets and asteroids with the Earth have certainly captured Hollywood’s imagination and the headlines, and we will examine this often bizarrely misinformed topic in considerable detail. Collisions are more general than this, however, and we will study three main themes: collisions between objects in the Solar system; collisions of all kinds, including gravitational interactions, between stars; and collisions between galaxies. As you scan the syllabus you will readily see these three areas. With this approach you will see many of the objects that you would see in a general survey of astronomy, but we will be able to probe more deeply into specific areas as we go along.

Text book

For the first half of the course (prior to spring break), we will be using the following textbook:

Night Comes to the Cretaceous, JL Powell, c. 1998 Harcourt-Brace

For the second half, you may find it useful to consult any good introductory astronomy text.

Website

The course website is at the following URL:

http://www.astro.umd.edu/~chris/Teaching/ASTR220_Spring_2003/astr220_spring_2003.html

Copies of the course materials as well as links to other useful information will be posted on this website regularly.

Expectations

Attendance: This course is more than a lecture series, and in order to successfully complete this course I expect you to attend all classes. We meet on all Tuesdays and Thursdays that the University has scheduled for classes during the semester.

Absences and academic honor code: University regulations for excused absences and academic honesty apply strictly in this class. If you have any questions about these policies, please ask me or review them on p. 35 of the Spring schedule of classes. If you must be absent for a university-approved athletic event or religious observance, please contact me by the last add date, February 10, to make appropriate arrangements. If you will be absent for any other reason and wish to receive full credit for missed assignments, examinations, or participation, you must contact me before missing class to discuss missed material and to arrange bringing in a valid excuse. Violation of the academic honor code is an extremely serious matter that will be immediately referred to the Student Honor Council.

Preparation: I expect that you will come to class prepared to participate and learn. You will understand the lecture material more easily if you complete the reading assignments (given in the following class schedule) before coming to class. It is important that you participate in classroom discussion and ask questions. I encourage you to ask questions in class, by coming to office hours, or by sending me email.

Study habits: Study wisely and ask for help if you need it. Studying only on the night before exams is unwise: it is easier to keep up on a daily or weekly basis. When you have questions, please see me or the TA: we are here to teach!

Grading

Grades will be determined by a combination of homeworks, midterm and final exams, and quizzes and in-class activities. The scoring breakdown is:

Midterm 100 points

Final exam 140

Homeworks (4) 100

In-class quizzes (3) 30

Book review 10

Other in-class activities 20

Total 400

Examinations: Exams will consist of multiple choice and short-answer or short-calculation questions. Make-up exams are only possible for students with valid absences according to University policy who have informed me before the exam is given – my email and phone contacts are at the beginning of this document and are available through University information. It is your responsibility to contact me to arrange for a make-up exam within one week of the original exam date if full credit is to be granted. The final grades will be based on the scale given in the table below. The table gives the minimum letter grade that you will attain for a given number of points. Any curving will be done such as to give you a better letter grade.

Letter grade	Percentage	Points
A	90% and above	>359
B	80-89	320-359
C	70-79	280-319
D	60-69	240-279
F	< 60	< 240

Homework: Homework is due by the beginning of class on the lecture date indicated. Homework handed in after class has begun will be considered late and will have 20% of the credit deducted. Late homework will not be accepted after the beginning of the class following its due date.

Homework must be typed or neatly handwritten: it is your responsibility to communicate your answers and ideas clearly to us and to others. We must be able to read and understand your homework for you to receive full credit. Please show your calculations on all problems and justify your answers; a brief yes or no answer is generally not enough.

Formulate the answers using your own words only: copying from the book or elsewhere is plagiarism and is a violation of the academic honor code. Do not copy from your friends: this also falls in the category of academic dishonesty. If you need to quote material from other sources, you must properly attribute its origin. If you have any questions about this, please ask me.

Extra credit: There are two possibilities for extra credit. You may do either or both of the following assignments once each for a total of up to ten points of extra credit.

1. You can earn upto 5 points of extra credit by attending the public lecture “When Galaxies Collide” by Prof. Margaret Geller which is to be held at the National Academies of Sciences in downtown DC on 24^th April 2003 at 6.30pm. I will give you directions and information on how to obtain free tickets closer to the time.
2. Any time after the first midterm, you can earn up to 5 points of extra credit by watching one movie, video, or similar program related to the class. Before you settle on something, check with the instructor for approval. Collisions have been the topic of several recent television shows and movies, and you may want to pick from those. Examples of possible subjects are the movies Deep Impact or Armageddon. The assignment is to write a two page critical review of the approved subject, analyzing its astronomical aspects based on the material covered in ASTR220.

Students with documented disabilities: Students with documented disabilities who wish to discuss academic accommodation should contact me by the last add date, February 10.

PRELIMINARY SCHEDULE

Date	Topic of class	HWs/quizzes	Reading
1/28/2003	Introduction to the course
1/30/2003	Structure and formation of the solar system
2/4/2003	Effects of cratering in the solar system		Preface & Prologue
2/6/2003	The physics of crater formation
2/11/2003	The Earth's Moon		Chapters 1-3
2/13/2003	The Earth's surface	HW1 due
2/18/2003	The nature of impactors: Comets and asteroids		Chapters 4-7
2/20/2003	Two spectacular cases: Tunguska and SL9
2/25/2003	Mass extinction of the dinosaurs and the K-T boundary		Chapters 8-10
2/27/2003	The Alvarez theory: global effects of a massive impact	quiz 1 (in class)
3/4/2003	The K-T crater
3/6/2003	Other mass extinctions	HW2 due	Chapters 11-13
3/11/2003	Night comes to the Cretaceous: in class discussion of the book
3/13/2003	Future impacts	Book review due
3/18/2003	Discussion of video, assessment of risk, and pre-exam review
3/20/2003	MID-TERM EXAMINATION
3/25/2003	SPRING BREAK
3/27/2003	SPRING BREAK
4/1/2003	Introduction to stars
4/3/2003	Formation of stars and solar systems
4/8/2003	Stellar evolution
4/10/2003	Stellar death	quiz 2 (in class)
4/15/2003	Interacting stars
4/17/2003	Gamma-ray bursts	HW3 due
4/22/2003	Our galaxy
4/24/2003	The extragalactic zoo
4/29/2003	Colliding galaxies	quiz 3 (in class)
5/1/2003	Active galactic nuclei
5/6/2003	Does our galaxy contain a central black hole?
5/8/2003	Beyond black holes: time-warps and wormholes	HW4 due
5/13/2003	Discussion and review of class
5/16/2003	FINAL EXAMINATION (8.00-10.00am)