ASTR-310 Astrobiology Quiz #1 Study Guide

Date: Friday September 30th

* You do not need a "lockdown" or exam browser nor webcams watching you take this quiz.

* The quiz will consist of only 15 multiple-choice questions. You will have 30 minutes to take the quiz, so you should not feel pressured for time (this is twice the amount of time students would have if we were meeting in person).

* This is an "open-book exam" - you may use your own notes, the class notes, the class lectures, the textbook, other textbooks, and a calculator. However you may not use old copies of quizzes or exams from this course, ask anyone for assistance from anyone other than the professor (me), nor search the internet for answers to the questions. Cheating will results in automatic failure of this exam, a letter dediuction in the course grade, and will be reported to the Center for Student Rights and Responsibilities for additional penalties. Be aware that there may be questions on the quiz designed to catch students who cheat by looking up the answers on the internet.
Please review the "Academic Honesty" and "Statement on Cheating and Plagiarism" sections of the syllabus document and also the page "Plagiarism Reminder" next to Homework #1 in Module 1, or ask if you have any questions.

* You may start at any time between 6am and 10pm (Pacific time), but once started, you must complete the exam within 30 minutes. To limit any potential cheating by some of our weaker and less honorable students, you can only see one question at a time and you will not be able to skip ahead or go back to an earlier question. (This is for security reasons, and I apologise for the inconvenience. But for just 15 questions, this won't be so bad.)


General quiz-taking tips:
- Do not wait until late in the evening to take the quiz. If you lose internet connection or anything like that, there is no way to allow a make-up quiz. Unless there is a valid reason with documentation (for example, a medical emergency) as to why you could not take the exam anytime between 6am and 10pm it is not possible to take a make-up exam.
- If possible, use a computer that has an ethernet cable connection, as these have better reliability than wifi.
- Close any other programs that might interfere with your internet connection. But of course, keep the ebook textbook readily available.
- Prepare a quiet area where you wont be distracted. Have some desk space available for your notes and textbook.
- If you are using a laptop, consider using a plug-in mouse to make it easier than a touch pad to click on the answers.
- You won't need a calculator for this exam.
- If you are worried about your internet connection being unreliable, take the exam while on campus.

* Quiz-preparation strategy:
Just because this is an open-book quiz, don't fool yourself into thinking you don't need to study much. Experience has shown that if you don't already have a good idea of what the correct answer is, having the notes and textbook available won't help as much as you might hope - it takes too long to hunt through the notes or chapters to find the answers. This is especially true with an online e-book. So with that in mind, here are some tips:
(i) Study for this quiz as if it is not open-book. This will help you learn the material better.
(ii) Do not rely too heavily on being able to access your notes or especially the textbook. It may take a long time to look up an answer if you can't limit the answer down to just two choices. So be judicious with your time. If you study and are prepared, you might not even need the textbook. Of course have them ready, but don't let them be a crutch and slow you down. Trust yourself.
(iii) This study guide is a guide to help you identify what you know and what you are not sure of, and thus focus on those things that need attention. It is a tool; the study guide is not designed to something you study, it is designed to check your level of preparation. Some students ask if all the questions on the quiz are listed here - the answer is definitely "no". That's no the way the study guide works. But if you understand all the concepts listed and can correctly answer all the questions, you'll likely do very well on the quiz.

* And lastly, please keep in mind that a team of SDSU experts has helped create this course and have advocated using small, frequent, low-stakes assessment strategies. Thus, this is a short, low-pressure quiz. It counts for only 5% of your grade. It is not an exam. You should have plenty of time to take the quiz, and you can begin the quiz anytime you want. And it is open-book. You should feel no need to cheat. It just isn't worth it. Please don't look up the answers on the internet, don't cheat off of old quizzes, and don't ask anyone for help. [If you have ever had to use lock-down browsers (like Respondus) or had the professor and TAs watching and recording you while you take an exam on Zoom, you know what a miserable experience that is. We are better than that.]

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This exam covers all material presented in Module 0 and Module 1 (Lectures 1 through 16), and the relevant sections of the textbook. If any webpages were assigned as required reading, that material will also be convered on the quiz. (Note: The webpages needed for the written Homework #1 assignment are not included - that material will not be on the quiz.) The topics discussed in the class lectures are the most important. The short on-line notes are helpful, but incomplete. We cover much more than just the on-line lecture notes, so be sure to study the lecture material, not just the abbreviated class notes. The textbook material is less important than the notes, but is more detailed in some areas and will really help you understand the topics.

In the textbook, we have covered the following:
Ch 1
Ch 2 Section 2.3 and 2.4 (just the parts about the scientific method)
Ch 3
Ch 4 Section 4.3.2 Life During Early Earth's History (about the Moon)
Ch 4 Section 4.4.4 Why Does Earth Have a Magnetic Field?
Ch 4 Section 4.6 Formation of the Moon
Ch 10 Sections 10.1, 10.2, 10.3, 10.4 about "Habitable Zones"
Ch 11 Section 11.1 about the different types of stars
Ch 11 Section 11.2 on the Doppler effect and finding exoplanets using the RV method; especially p 361-363 and 369-370

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Here is a list of some material that you will NOT be responsible for knowing
Skip most of the start of Chapter 2, specifically the sections on the ancient astronomy and planetary motion up through Newton's laws (page 16-27).
However, DO NOT skip the section about parallax on page 20 especially fig 2.6, and do not skip sections 2.3 & 2.4. You can skip fig 2.17 (pages 34-35) and the formula for gravity on page 37.
Skip all of the "Movie Madness" sections throughout the book
Skip anything about neutron stars, pulsars; gamma ray bursts.
Skip anything about radioactive decay (for Exam #1 only - you need to know this for later).

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The quiz will contain 15 multiple choice questions. Most multiple-choice questions will have 5 choices (a)-(e) or 6 choices (a)-(f), but some may have more. There is no penalty for guessing so do not leave any answers blank!

You will not need to know the values of any physical constants except the speed of light "c". (which you can look up in you notes if you need to).
* Please memorize the speed of light (in sensible units, not miles per hour!) or at least have the number handy. You will not need to know exactly how many meters are in a parsec or how many meters in an AU, or how many meters in a light year. But you do need to know that 1 Mpc = 106 pc, and things like that (basically the metric system). You definitely need to know the definition of an AU, light year, parsec, etc., though not the numerical value. You may be asked to do a few very simple math-related problems. You will be asked questions that test your understanding of certain laws, even if you are not asked to calculate anything using that law. For example, while you may not be asked "At what wavelength and part of the electromagnetic spectrum does the peak of blackbody radiation from Venus' surface occur (given that Venus' surface temperature is 750 K)?", you may be asked "What does Wien's law tell us?". You won't be asked, "How old is the Universe if Ho = 50 km/s per Mpc?", but you may be asked "How do you determine the age of the Universe from Hubble's constant?".

Many questions will ask "Which of the following is FALSE?". From a teaching and learning point of view, these are much better questions than "Which is true?". But be careful - read all the answers carefully and decide if each statement is true or false. Most will be true. Take your time.
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Some typical exam questions:

Which of the following is FALSE (NOT TRUE)?
A) The Doppler effect can be used to measure the radial velocity of a star.
B) We can measure the distance to galaxies using parallax.
C) Spectroscopy can tell us what a star is made of.
D) Spectroscopy can tell the temperature of a star.
E) Stars are made mostly of hydrogen.

Complete the analogy: A "kilogram" is to a "gram", as a "kilometer" is to a
A) "foot"
B) "meter"
C) "yard"
D) "centimeter"
E) "light-year"

Complete the analogy: A "Gigabyte" is to "byte", as "billion" is to
A) "one"
B) "ten"
C) "one tenth"
D) "million"
E) "billion"

Complete the analogy: A "mile" is to a "yard", as a "kilometer" is to a
A) inch
B) yard
C) meter
D) nanometer
E) Kelvin

Complete the analogy: "Kelvin" is to "Celsius", as a "light year" is to
A) year
B) parsec
C) kilogram
D) Fahrenheit
E) month
(hint: the answer is not choice A)

Suppose a spectral line from an object in space was shifted from 5007.0 to 5100.0 Angstroms. What can we tell about this object?
A) It is a star.
B) It is very cold.
C) It is blueshifted, hence coming towards us.
D) Its radial velocity is positive, meaning it is moving away from us.
E) It is a planet in a distant galaxy.
F) It is an exoplanet.

The most abundant element in the Universe is
A) carbon
C) oxygen
C) helium
D) hydrogen
E) iron
F) nitrogen
G) water

Suppose Star #1 is cooler than Star #2. We can say with a high degree of certainty that Star #1:
A) appears fainter in the sky than Star #2
B) is bluer than Star #2.
C) is redder than Star #2.
D) is more massive than Star #2.
E) choices A) and B).
F) choices A) and D).

A web site reports the discovery of "a 25 billion year-old O star."
What is wrong with the report?
A) O stars only last a relatively short time, about 10 million years.
B) The star would be so faint that we couldn't see it.
C) The star would be older than the Universe.
D) both choices A and C
E) choices A, B and C

Suppose a galaxy is 400 million parsecs from the Milky Way.
What is the recessional velocity of this galaxy?
(Assume Hubble's constant H0 = 75 km/s/Mpc.)
(Hint: 400 x 75 = 30,000)
A) 400,000,000 km/s
B) 1/10 the speed of light
C) 75 km/s
D) twice the speed of light

The Doppler effect can be used to:
A) measure the distance to a star using the star's parallax
B) determine what a star is made of.
C) measure the temperature of a star.
D) measure the radial velocity of a star

Which gases were *NOT* present soon after the big bang?
A) hydrogen
B) helium
C) carbon dioxide
D) oxygen
E) choices C and D

Which element is *NOT* created primarily by thermonuclear fusion in the cores of stars?
A) hydrogen
B) helium
C) carbon
D) oxygen
E) iron

Which of the following is ** FALSE ** ?
A) O stars are the brightest stars
B) M stars are the least massive stars
C) At the end of their lives, O-type stars will become a supernova
D) At the end of its life, the Sun will become a white dwarf
E) At the end of its life, the Sun will become a supernova

Which of the following is ** FALSE ** ?
A) there are a billion years in one gigayear (Gyr)
B) the total lifetime of the Sun is about 10 billion years
C) the age of the Solar System is about 13 billion years
D) the center of the Milky Way has a supermassive black hole
E) the habitable zone is a range of distances from a star where liquid water can be present on a planet's surface


More hints on what to know and focus on:
- What is "astrobiology"?
- What is the speed of light (c) in km/s? In m/s?
- What is a "light year"? Why is it a distance, not a time?
- How many nanometers in a kilometer? How many micrograms in a kilogram?
- What is temperature?
- What does "absolute zero degrees Kelvin" mean?
- What is an "AU"?
- What does it mean to say that by looking at the distant stars and galaxies are are looking back in time?
- Approximately what is age of the Solar System?
- What is the difference between a terrestrial and Jovian planet?
- Roughly what is the radius of the Solar System?
- Roughly how far away are the nearest stars?
- How long would it take for light to travel to the nearest star and back?
- How far away is the galactic center?
- In the opening sequence of the film Contact, why do we hear radio broadcasts from the past?
- What is an ion? What is a neutron? An isotope? What defines an element?
- What is an "organic molecule"?
- What is the atomic number of hydrogen?
- What is the difference between a "photon" and a "proton"?
- What is the electromagnetic spectrum?
- What is the "visible" or "optical" range of light in nanometers?
- What is spectroscopy?
- What does Wien's law tell us?
- If you see a blue star in the sky, is it likely to be hot or cold (astronomically speaking)?
- What is the Doppler effect?
- What is "cosmology"?
- What is the surface temperature of the Sun?
- What is its spectral type? - How old is the Sun? How long will it last?
- What is the ultimate fate of the Sun at the end of its life?
- If a star is moving away from us, is its velocity positive or negative?
- What is an emission line?
- What is Hubble's constant?
- What is big bang nucleosynthesis?
- Approximately what is age of the Universe?
- Why is the finite age of the universe important for astrobiology?
- What is the "cosmic microwave background"?
- What is a redshift?
- What are some of the pieces of evidence for the big bang theory?
- What does "panspermia" mean?
- What is "Occam's Razor"?
- Why can't we trust "subjective" evidence?
- What makes a hypothesis a valid scientific hypothesis?
- What is the difference between a hypothesis and a theory?
- What is "subjective evidence" and what are its limitations?
- What is "thermonuclear fusion"?
- What is the "habitable zone"?
- What is a "planetary nebula"?
- What is "stellar evolution"?
- If you see a blue star in the sky, is it likely to be young or old (astronomically speaking)?
- What does it mean to say "We are all made of `star stuff'?"
- What are supernovae? Why are they important for astrobiology?
- What is the diameter of the Milky Way?
- What is a nebula?
- What is a white dwarf?
- What is a cosmic ray?
- How long does it take for a star & planet system to form?
- How long does an M-star last?
- What things make the Milky Way more friendly for life now than 12 billion years ago?
- What is an exoplanet?
- How do we use the Doppler effect to find extrasolar planets?
- Why are cosmic rays important for biology?
- What is a protostellar disk?
- Why are protostellar disks flat?
- What is considered the best hypothesis for the origin of the Moon?

- What are the top five most abundant elements in the Universe?
- When speaking in a scientific context, why does the phrase "its only a theory" make no sense? Why is this an oxymoron?
- Why can't you see stars in the background sky in the Apollo photos (or any other photos of spacecraft or planets or similar things)?
- What is NASA's "Astrobiology Institute"?
- What is NASA's "Astrobiology Roadmap"?
- Do you understand the radial velocity / Doppler method shown in the NBC Learn video Science Behind the News: Extrasolar Planets?

Some deeper questions to ponder:

** Suppose a planet is discovered orbiting at a distance of 1 AU from its star. If that star is an O star, do you expect that it is possible to have life on that planet? What if it were an M star instead of an O star?

** Our eyes, and indeed they eyes of nearly all living things on Earth, are most sensitive to light in the visible part of the electromagnetic spectrum. This is because our eyes have evolved to match the light output of our star. Suppose we find alien life on a distant planet, far from the solar system. Further suppose that the eyes of the life on this planet are most sensitive to the near infrared part of the spectrum. Do you think the alien planet orbits a star that is hotter or cooler than our Sun? Why?



Good Luck!