Welcome to the Alien Worlds syllabus. We hope that as you start this course you refer to the material here, which provides a general description of the course's content and rules. Please come back and check the syllabus if you have any questions regarding the course. Read on, knowledge seekers!

If you want a downloadable copy of the syllabus, it can be found here.

A BOUT A LIEN W ORLDS

We live in an amazing time of discovery! For the past two decades astronomers have begun identifying and studying planets around other stars. We call these alien worlds extrasolar planets or exoplanets. The subfield of astronomy that their discovery has spawned has become one of the most exciting topics in all of science. In just a short amount of time we have gone from knowing about the eight planets in our solar system to several thousand planets orbiting distant stars in our Galaxy. Our recent discovery and study of the myriad exoplanets has given us new perspective about our place in the Universe and shown us that our solar system is not unique. In fact, in the just the last couple of years, we have found for the first time in human history that planets around other stars not only exist, but are incredibly common.

This class, Alien Worlds, will introduce students to some of the fundamental scientific concepts and clever astronomical techniques that we use to both discover and characterize exoplanets. In addition to viewing short lectures, students in Alien Worlds will hear interviews from other astronomers, watch demonstrations of physical concepts, interact with computer simulations of planets orbiting other stars, and will complete assessment exercises. Throughout the course, students will have the opportunity to ask questions and interact with the Alien Worlds team and other students on our discussion boards. Students who complete this course will have a basic understanding of exoplanet science and a better perspective of their place in the Universe.

A BOUT THE T EAM

Andrew West, Professor – Andrew West is an Assistant Professor in the Department of Astronomy at Boston University. West’s major research interests center around using low-mass stars (the smallest, yet most numerous stars in the Milky Way) to understand the structure and evolution of the Milky Way galaxy, the environments that host exoplanets, and various processes on the stars themselves. Professor West has a strong commitment to his role as a scholar-teacher and has been the instructor for Alien Worlds at Boston University since 2011. He was recently awarded an NSF CAREER grant and a Cottrell Scholarship for his research and teaching endeavors, including his efforts to increase the diversity of Astronomy and other science fields.

Brandon Harrison, Course Coordinator – Brandon Harrison is a second year PhD candidate at the Boston University Astronomy Department. His research focuses on studying dark matter around galaxies by using computer simulations. Brandon has worked with Professor West in the past to teach this course to undergraduates and also has experience helping to teach higher level astronomy courses.

Liane Tarnecki, Undergraduate – Liane Tarnecki is a sophomore Astronomy and Physics student at Boston University. Her research focuses on modeling plasma instabilities in the ionosphere. Liane was introduced to astronomy research through Professor West's freshman seminar.

C OURSE O UTLINE

Students taking this course will learn from nine separate modules which will be released slowly over the course of seven weeks.

Below is a table giving relevant module information.

Module Content Introduction



Released:

Fri. Oct 31 at 1:00 PM (EDT) Covers basic terminology and concepts of astronomy, including but not limited to the units used in astronomy, some of the basic properties of planets in our Solar System, and our place in the Universe. You will learn about giant astronomical size and distance scales and learn how to scale these down to more comprehendible sizes. Planetary Motion



Released:

Fri. Nov 7 at 1:00 PM (EST) Students will learn about Kepler's laws, which describe how planets orbit their stars as well as the basics of gravity and how the gravitational force varies between different planets and planetary systems. Light



Released:

Fri. Nov 14 at 1:00 PM (EST) The nature of light is discussed, particularly how the light from a star tells us properties of that star. We will cover the basic principles of varieties of light and learn about the technique of spectroscopy, where atoms produce (or absorb) specific wavelengths (or colors) of light that we can observe across the vast distances of the Galaxy and the Universe. Transit Method



Released:

Fri. Nov 21 at 1:00 PM (EST) Describes the process by which we detect the existence of planets as they pass in front of their host stars. The dimming of light from this occultation indicates a planet exists (called the Transit Method) and gives us information about the size of the planet. Planet Properties



Released:

Mon. Nov 24 at 1:00 PM (EST) We examine the basic properties of planets both in and out of our Solar System, including how we can determine the bulk materials from which a world is made. Radial Velocity Method



Released:

Mon. Dec 1 at 1:00 PM (EST) As planets orbit their host stars they cause the central star to wobble as it attempts to balance on a cosmic seesaw. We can look for this wobble in stars as a way to detect exoplanets (called the Radial Velocity method). This method also gives us information about the mass of the orbiting exoplanet. Stars as Hosts of Exoplanets



Released:

Mon. Dec 8 at 1:00 PM (EST) Until this point in the course, we have always assumed that all stars are like the Sun. In reality, the Sun is a medium-sized star that is not even the most common type of star. We will introduce different classes of stars and the "H-R Diagram", which organizes stars into a convenient plot. This module also examines how different host stars affect the detection, characterization and properties of their orbiting planets. Star and Planet Formation



Released:

Fri. Dec 12 at 1:00 PM (EST) This module covers the basics of how stars and planets form, including how to create rocky, Earth-like planets, and gaseous, Jupiter-like planets. We discuss the evolution of planetary systems and how odd planets like "Hot Jupiters" might form. Life in the Universe



Released:

Fri. Dec 19 at 1:00 PM (EST) One of the overarching goals in our search for exoplanets is to find life elsewhere in the Galaxy. We discuss the conditions for worlds to be habitable, how we might estimate the number of alien civilizations with which we could communicate, and some of ways that we might communicate with them. Final Exam



Released:

Fri. Dec 19 at 1:00 PM (EST) A final exam testing every component of the course. This counts for 20% of your overall grade. End of Course



Date:

Mon. Jan 5 at 5:00 PM (EST) The course officially ends on this date. The content will still be available after the course closes, but those seeking a Verified Certificate must achieve an overall grade of 60% by this date.

A SSESSMENTS AND G RADING

At the end of each module we will have a short assessment which is meant to test your comprehension of the course material for that module. There will also be a final exam at the end of the course which tests on all the topics presented throughout the course. For those of you who are taking the course for a Verified Certificate, you must meet a minimum grade of 60% in the course. The grading breakdown is such that the final exam is worth 20% of your overall grade and the individual module assessments are worth the other 80% - each being weighted equally.

Each assessment will be open at the time of the module's release. The deadline for all assessment and final exam completion is the end of the course. In other words, you may choose to not complete Introduction assessment until the very end and it will still be open for you to do so. However, we recommend that you complete the assessments as you go.

D ISCUSSION F ORUM G UIDELINES

We hope that you find the discussion forums to be a useful component of this online course. The discussion forums are meant to be an area where the students can interact with each other, ask questions, or talk to the course staff. We greatly encourage you to use these forums to their full extent.

To aid in this goal, we ask that you do not post comments which are derogatory, defamatory, or in any way attack other students. Be courteous and show the same respect you hope to receive. We will have discussion forum moderators who will delete posts that are rude, inappropriate, or off-topic. We also ask that you do not post answers to assessment questions on these forums. You may discuss how to approach a problem or help other students who may have questions, but please to not directly provide answers. Commenters who repeatedly abuse this public forum will be removed from the course.

Additionally, there is a new feature in the discussion forums that allows you to select from two post types, which are Question and Discussion. When posting to the discussion board, please bear in mind that the Question type is meant for specific issues with the platform or with content, while the Discussion type is meant to share ideas and start conversation.

O FFICE H OURS

Throughout the course Professor West will hold office hours for students to personally ask him questions and interact with him. These office hours will be through Google Hangouts. Instructions for how to join will be sent out with reminders before each office hour. The office hour times are listed below.

Wednesday November 12 12:00PM - 1:00PM EST Tuesday November 25 9:00AM - 10:00AM EST Tuesday December 9 5:00PM - 6:00PM EST Wednesday December 17 1:00PM - 2:00PM EST

FAQ

Q: Should I email the professor or any persons involved with this course directly?

A: No. If you feel the need to contact the course staff involved in this course, please do so through the Discussion Forum.

Q: Do I need to buy any personal materials to take this course?

A: No. You do not need to purchase textbooks or any materials to aid you in completing the course. If you do wish to have supplementary material, we encourage you to look on the Wiki.

Q: I've never taken an edX course before and this is confusing. What do I do?

A: There will be a pre-course module that beginners can watch. It explains in detail how to use the edX platform. For further information, please visit the demo edX course.

Q: I found a mistake in the course. Where do I report it?

A: On the Wiki page is a specific section for "Errata & Suggested Corrections". You can go there, edit the page, and post information concerning any errors or issues you have found. We will try to fix them as soon as possible.

Q: When I enter an answer for an assessment question, it does not accept my answer. I feel that my answer is correct, what do I do?

A: First, make sure that for numerical inputs, you do not include units or anything which is not a numerical value. Answers in scientific notation such as "1E-4" are allowed, but you cannot put "1E-4 meters". Check your spelling for text inputs. The answers are not case sensitive though. For short answer questions, make sure to answer each question that is asked. If you feel that you have followed these guidelines and that you are still being incorrectly marked wrong, please post this as an issue on the "Errata & Suggested Corrections" page of the wiki.

Q: This is all so cool! I want to learn more.

A: Well that wasn't really a question, but if you're interested in learning more information, you can go to the Supplementary Materials section, which gives all sorts of fun astronomy related things that will help you learn even more.

Q: Is the answer to this question no?

A: Now you're just being annoying.

T IME Z ONES

A note about time references: Time will be reported by course staff as Eastern Daylight Time, North America (EDT) or Eastern Standard Time, North America (EST). Any times listed by edX, such as due dates listed on the course site, will be reported in Coordinated Universal Time (UTC). The course staff will make every effort to make times and time zones as clear as possible. There are various time zone converters on the web such a this one.

We adhere to Daylight Savings which occurs on November 2nd. The clocks will be set back one hour and we will be on Eastern Standard Time (EST). Please make sure to take notice of this time change, especially if your region does not adhere to Daylight Savings. The time zone converter will take this time change into account.

H ONOR C ODE

The edX platform assumes a certain level of decorum and responsibility from those taking this course. Please review the edX Honor Code, which is reproduced below.

By enrolling in an edX course, I agree that I will: Complete all mid-terms and final exams with my own work and only my own work. I will not submit the work of any other person.

Maintain only one user account and not let anyone else use my username and/or password.

Not engage in any activity that would dishonestly improve my results, or improve or hurt the results of others.

Not post answers to problems that are being used to assess student performance. Unless otherwise indicated by the instructor of an edX course, learners on edX are encouraged to: Collaborate with others on the lecture videos, exercises, homework and labs.

Discuss with others general concepts and materials in each course.

Present ideas and written work to fellow edX learners or others for comment or criticism.

C REDITS AND A CKNOWLEDGEMENTS

As with any major effort, this course would not be possible without the large contributions from many sources. We would like to extend a special thanks to the various teams who have put in countless hours of work to help create this course. Specifically, we want to thank the following people and organizations who have contributed a large amount of effort towards helping this course become a reality. Romy Ruukel, Tim Brenner, Vanessa Ruano for administrating this process and being responsible for every aspect of making this course. Nancy Marrs, Chris Palmer, John Hawkes, Mark Helton, Patrick Hines, Dave Pryke, and Phil Zekos for filming and editing the videos that appear in this course. Hilary Orenberg, Katia Oleinik, Charlie Guerrero, Andrew Bauer for creating the visualizations that appear in this course. The Boston University Astronomy Department and specifically Quinn Sykes for allowing us to use their resources, time, and efforts. Sadia Hoq and Kolby Weisenburger who put in a huge amount of effort in creating this course. Andrew Abrahamson and Adam Brilla who let us to use their media room to create the tablet captures. Sean Casey and the Boston Public Library for allowing us to film and handle their rare books. Toby Smith from the University of Washington for the use of some of his Astronomy 105 course material. The many beta testers who worked to track down errors in the course. And last, but not least, all the people who agreed to be in our interviews.

Secondly, there are various copyrighted or third party images which has been used in this course under the gracious allowance of the proper authors or organizations. While these sources are credited in their respective locations, we would like to reiterate these credits here.

Light Module

Image: Color Chart of PKS 1510-08

Credit: Frankfurt Quasar Monitoring

Transit Method Module

Image: Fig. 2 - Transit Curve

Credit: Charbonneau et al. 2000, ApJ, 529, L45-48 © AAS. Reproduced with permission

Radial Velocity Method Module

Image: Fig. 4 - Radial Velocity Curve of 51 Peg

Credit: Adapted by permission from Macmillan Publishers Ltd: Nature (Mayor, M., Queloz, D. 1995, Nature, 378, 355), copyright 1995



Image: Fig. 3- Exoplanet Mass vs. Radius

Credit: Zeng, L., Sasselov, D. 2013, PASP, v. 125, no. 925, pp. 227

Stars as Hosts Module

Image: Fig. 8 - Planetary Occurence vs Stellar Temperature

Credit: Howard et al. 2012, ApJS, 201, 15



Image: Fig. 2 - The Habitable Zone

Credit: Seager 2013, Science, v. 340, no. 6132, pp. 577



Lastly, we would like to thank NSF and SETI for allowing us to use their images.

T ERMS OF S ERVICE

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