Lab 4: The Moon

Credit/Permission: For text, © David Jeffery. For figures etc., as specified with the figure etc. / Only for reading and use by the instructors and students of the UNLV astronomy laboratory course.

Group Number/Name:

Name:

Partner Names:

Favorite Report: Y / N

Task Master:

Task 1: Preparing to Observe the Moon.
Task 2: Locating Moon Features.
Task 3: Lunar Phase and Illumination.
Task 4: Blank Moon Maps.
Task 5: Naked-Eye Observation of the Moon.
Task 6: Telescopic Observation of the Moon (IPI only).
Task 7: Cell Phone Image (IPI only).
Task 8: Labeling Moon Maps.
Task 9: Image Processing (IPI only). Optional at the discretion of the instructor. It is probably good to do this task if you want/need to do Lab 4 and the Moon is unobservable. Task 10: Inertial Frames and Non-Inertial Frames.
Task 11: Center of Mass Question.
Task 12: To-Scale Diagram of the Earth-Moon System (IPI only).
Task 13: The Lunar Month and the Sidereal Month.
Task 14: Calculating the Sidereal Lunar Month from Kepler's 3rd Law. Optional at the discretion of the instructor.
Task 15: Werewolf.
Task 16: Lunar Phase Simulator Questions.
Task 17: Lunar Phase Problem Examples---What You've Been Waiting For.
Task 18: Lunar Phase Problems.
Task 19: Axial Rotation Period and Lunar Day.
Task 20: Giant Impactor.
Task 21: Lunar Geology Tidbits.

End of Task

Task 1: Preparing to Observe the Moon:
Sub Tasks:
1. Read the Moon-map figure below (local link / general link: moon_map_side_near.html). Have you read it? Y / N
2. What is the most obvious lunar crater in the image map as reckoned by most people? CIRCLE the answer.
  1. Crater Aristarchus. ___
  2. Crater Copernicus. ___
  3. Crater Kepler. ___
  4. Crater Tycho. ___
  5. Crater Zwicky: Named for Fritz Zwicky (1898--1974). ___
End of Task
Task 2: Locating Moon Features:
Sub Tasks:
1. Without looking back at the Moon-map figure above (local link / general link: moon_map_side_near.html), mentally locate in the map in your mind:
  1. NSEW on the sky.
  2. Crater Copernicus.
  3. Crater Plato.
  4. Crater Tycho.
  5. Mare Imbrium.
  6. Mare Tranquillitatis.
  7. Oceanus Procellarum.
  Couldn't do it, eh? Look back at the Moon-map figure above (local link / general link: moon_map_side_near.html), and keeping trying until you can do it.
2. Have you succeeded at last? Y / N
End of Task
Task 3: Lunar Phase and Illumination:
Sub Tasks:
1. Read the figure below (local link / general link: moon_image_now.html). Have you read it? Y / N
2. What is the current lunar phase?
  Answer:
3. The fraction of the Moon illuminated by sunlight is called the (lunar fractional) illumination.
  There are 3 ways to find the illumination for today: (1) the super easy way---which you are NOT to use, (2) the easy way, (3) the hard way. Choose one way out of way (2) and (3), and calculate the illumination for today or the day you are doing this lab.
  1. Super easy way: Just click Date & Time: Lunar phase: Current and read off the illumination.
  2. Easy way: Just estimate it from the Image 2 plot in figure below (local link / general link: moon_image_now.html).
    Note that (today's date) - (last new moon date) = (day count for the plot).
    To find the last new moon date, see Date & Time: Lunar phase: Current or google "new moons this year".
    Answer:
  3. Hard way: Go to the USNO table linked in the figure below (local link / general link: moon_image_now.html) and find today's and tomorrow's calendar date
    Use the table to calculate the illumination for today (or day you are doing the lab) at 8 pm PST (9 pm PDT: recall the mnemonic spring ahead, fall back). You will have to do a linear interpolation to get the correct value. SHOW your calculation.
    Example calculation:
    Answer:
End of Task
Task 4: Blank Moon Maps:
Sub Tasks:
1. Before going to the roof to do observations, each person should print out one copy of the blank Moon map in the figure below (local link / general link: moon_map_blank.html).
2. RMI qualification: If you do NOT have a printer, you will have to sketch the blank Moon map for your use.
3. The blank Moon map is filled in OUTSIDE during observations: see below Task 5: Naked-Eye Observation of the Moon.
4. IPI only: Also print out one EXTRA COPY for the group as whole that is used for Task 6: Telescopic Observation of the Moon. This EXTRA COPY is the favorite-report-form copy and is appended to the favorite report form.
5. Has your group printed/sketched all the required blank Moon maps? Y / N
End of Task
Task 5: Naked-Eye Observation of the Moon:
Sub Tasks:
1. For IPI students: When the instructor says it's time for the observations, go to the roof to do the Moon observations.
  The observations may have to wait awhile depending on weather and which laboratory sections have observing time when.
2. For RMI students: You (in your group of one) can do the observations whenever you deem fit, but the Moon has be visible.
  So you may have to wait for the weather to be good, either on the night you choose first or on a later night.
3. If you have to wait, you should jump ahead to section The Earth-Moon System and carry on from there until you can observe.
4. This observation is naked-eye astronomy.
  Each group member observes the Moon with the naked eye and fills in their own blank Moon map following the instructions in the caption that goes with the blank Moon map (local link / general link: moon_map_blank.html).
  Keep looking for awhile and try to make out the features as best you can.
  For naked-eye observations, note that the Moon can be glaring when your eyes are dark adjusted (i.e., set to scotopic vision). So sunglasses might help.
  Have you done this? Y / N
5. For IPI students: Every group member should append their own naked-eye Moon map to their report unless the instructor only wants the favorite report form handed in---in which case append only the best naked-eye Moon map to the favorite report form. Label the naked-eye Moon map as the naked-eye Moon map.
  Have you done this? Y / N
End of Task
Task 6: Telescopic Observation of the Moon IPI only:
Sub Tasks:
1. This observation is with the telescope.
  For telescopic observations, the telescopes should have Moon filters on the eyepieces since otherwise the Moon will usually be too glaring to observe. The instructor should have put Moon filters before the lab period.
2. Each group observes the Moon with the telescope and helps fill in the group blank Moon map following the instructions in the caption that goes with the blank Moon map (local link / general link: moon_map_blank.html).
  All group members should help draw this map---do NOT let one person hog the telescope.
  Keep looking for awhile and try to make out the features as best you can.
  Have you done this? Y / N
3. Each group should append the telescopic Moon map to the favorite report form and label it as the telescopic Moon map.
  Have you done this? Y / N
End of Task
Task 7: Cell Phone Image (IPI only):
Sub Tasks:
1. Everyone in the group tries to take a TELESCOPIC image of the Moon with their cell phone if they have one.
  Did anyone get an image? Everyone. / Some did. / None did.
  Do NOT worry about your answer. You get the mark for any answer.
2. As an option for NO marks, you may do a little fun observing if you like. For example, if Jupiter ♃, Saturn ♄, or the Pleiades (for a sky map, see pleiades.html) are in the night sky, they are worth a look.
  Did you have a look? Y / N
3. After completing this task you can return to the lab room to continue with the inside parts of this lab. You may have to wait until the instructor has gone downstairs to open the classroom.
End of Task
Task 8: Labeling Moon Maps:
From the information in the reference Moon maps (laid on the tables by the instructor), the Moon map shown in the figure above (local link / general link: moon_map_side_near.html), the detailed Moon map in figure below (local link / general link: moon_map_side_near_topographic.html) AND/OR the Moon globes (laid on the tables by the instructor), LABEL all the Moon features in the checklist below that you can reasonably identify on the telescopic HAND-DRAWN Moon map from Task 6: Telescopic Observation of the Moon.
On the checklist, check off the Moon features you identified and LABELED.
Checklist for Moon features:
1. NSEW on the sky which is inverted on the telescopic hand-drawn Moon map if there was a star diagonal on the telescope ______
2. Crater Aristarchus ______
3. Grimaldi Crater ______
4. Crater Kepler ______
5. Crater Langrenus ______
6. Crater Plato ______
7. Crater Tycho ______
8. lunar terminator ______
9. Mare Crisium ______
10. Mare Fecunditatis ______
11. Mare Frigoris ______
12. Mare Humorum ______
13. Mare Imbrium ______
14. Mare Nectaris ______
15. Mare Nubium ______
16. Mare Serenitatis ______
17. Mare Tranquillitatis ______
18. Mare Vaporum ______
19. Montes Apenninus ______
20. Montes Recti ______
21. Oceanus Procellarum ______
Have you done this? Y / N
End of Task
Task 9: Image Processing (IPI only):
Let's do a little processing on a canned CCD image of the Moon.
Sub Tasks:
1. We will just process one of the old images:
  1. moon_2013_02_21_waxing_gibbous.FIT for waxing gibbous moon nights.
  2. moon_2013_02_26_full.FIT for full moon nights.
  Choose the image that is closest in lunar phase to the lunar phase of today.
2. Download the image to the desktop with name its default name (i.e., moon_2013_02_21_waxing_gibbous or moon_2013_02_26_full) using Firefox and NOT Internet Explorer unless you have the magic that makes that work for you.
3. You now process it as described below in How to Process the CCD Image of the Moon.
  Nota bene: The ordinary windows image opener will NOT work since the image is a FITS file.
4. Print out one copy of the processed image and append it to the favorite report form which should also have the telescopic hand-drawn Moon map appended if observations were carried out.
5. Have you APPENDED the required images? Y / N
6. From the desktop, delete the image file (i.e., moon_2013_02_21_waxing_gibbous or moon_2013_02_26_full) and "Yourfile.jpg" if you saved it.
  Have you done this? Y / N
- Task 10: Inertial Frames and Non-Inertial Frames:
  Sub Tasks:
  1. To better understand inertial frames and non-inertial frames, watch all the videos in subsection Inertial Frames and Non-Inertial Frames Videos below (local link / general link: frame_videos.html) and read the captions.
    Have you watched and read? Y / N
  2. For the Solar System, the ________________ define a sufficiently exact inertial frame for the measurement of rotational/orbital motions.
    1. asteroids. ___
    2. Moon's surface. ___
    3. fixed stars. ___
    4. Earth's surface. ___
    5. Pluto's surface. ___
  End of Task
- Task 11: Center of Mass Question:
  Sub Tasks:
  1. Have your read subsection Basic Facts of the Earth-Moon System above (local link / general link: Basic Facts of the Earth-Moon System) Y / N
  2. The formula for the center of mass of objects along a line is given in the figure below (local link / general link: center_of_mass_1d.html) along with an example calculation and some other important information. Read it. Have you done so? Y / N
  3. As another example, say you had m_1 = 3 M_Mo at x_1 = 0 R_eq_⊕ and m_2 = 5 M_Mo at x_2 = 2 R_eq_⊕, where M_Mo is a Moon mass and R_eq_⊕ is an Earth equatorial radius. Applying the formula given in the aforeasaid figure below (local link / general link: center_of_mass_1d.html) gives
```
          x_cm = (m_1*x_1 + m_2*x_2)/(m_1 + m_2)
               = [(3 M_Mo)*0 + (5 M_Mo)*(2 R_eq_⊕]/(3 M_Mo + 5 M_Mo)
               = (10  R_eq_⊕)/8 = 1.25 R_eq_⊕
               = 1.25 R_eq_⊕ * 1
               = 1.25 R_eq_⊕ * [ (6378.1370 km) / (1 R_eq_⊕ )]
               ≅ 80,000 km  ,
     
```
    where you note that some units cancel out like algebraic symbols since there are algebraic symbols and we have used the factor of unity (i.e., conversion factor) to do a conversion of units since you can always multiply by 1.
    Have you understood this example. Y / N
  4. Evaluate the center-of-mass position of the Earth-Moon system using Earth equatorial radii R_eq_⊕ and Moon masses M_Mo as the units (see List: Earth-Moon-System Facts above; also at local link / general link: moon_facts.html) and the center of the Earth as the origin (i.e., zero-point).
    The calculation will give the center of mass position in Earth equatorial radii. Then convert the answer to kilometers. SHOW your calculation or at least its setup.
    Answer:
  End of Task
- Task 12: To-Scale Diagram of the Earth-Moon System (IPI only):
  Each member of the group draws a side-view diagram of the Earth-Moon system SIMILAR to the figure above (local link / general link: moon_orbit_view_side.html) on a sheet of blank paper, but following the Directions below.
  Or if your instructor so directs, draw only one diagram and append it to the favorite report form.
  Directions:
  1. EVERYTHING has to be to-scale: mean Earth-Moon distance (AKA mean orbital radius of the Moon), Earth diameter, Moon diameter, orbital inclination to the ecliptic plane.
  2. The Earth-Moon will have to be approximately along the diagonal of the sheet of paper in order to make everything fit on the sheet.
  3. Scale the Earth's diameter to 1 cm.
  4. Recall the mean center-to-center Earth-Moon distance is ∼ 60 Earth equatorial radii = 30 Earth diameters.
  5. Draw the profile of the Moon's orbit and the ecliptic plane with the correct orbital inclination between them.
  6. You will need a protractor to accurately draw the orbital inclination.
  7. There will be rulers and protractors if the instructor has remembered to set them out.
  8. The figure below (local link / general link: howto_protractor.html) shows how to use a protractor.
  9. LABEL the following features: Earth, Moon, Moon's orbit plane, ecliptic plane, the inclination of the Moon's orbital plane to the ecliptic plane, ecliptic axis (centered on the Earth), Earth's axis extended into the celestial axis, Earth's axial tilt, the plane of the equator/celestial equator.
  10. Mark on the distances and angles.
  11. Your figure should look like the figure above (local link / general link: moon_orbit_view_side.html), but to-scale.
  12. Append the diagram to your Report Form or, if the instructor so directs, to the favorite report form. Have you done so? Y / N
  End of Task
- Task 13: The Lunar Month and the Sidereal Month:
  Sub Tasks:
  1. The relationship of the lunar month and the sidereal month are explicated in the figure below (local link / general link: lunar_month_sidereal_period.html).
    Read the figure. Have you done so? Y / N
  2. The lunar month falls into the class of synodic periods and the sidereal month falls into the class of orbital periods.
    The sidereal month can be calculated from the easily directly observed lunar month (which is the Moon's synodic period) and the sidereal year. How this done is explicated in the second figure below (local link / general link: synodic_period.html).
    Read the figure. Have you done so? Y / N
  3. The appropriate formula for obtaining the mean lunar sidereal month 27.321661547 days (J2000) ≅ 27.32166 days (to 7 digits) ≅ 27.3 days (which we label t_1) from the lunar month = 29.530588853 days (J2000) (which we label t and which is actually a synodic period) and the sidereal year = 365.256363004 days (J2000) (which we label t_2) is given in the second figure below (local link / general link: synodic_period.html). This formula is
```
     t_1 = t_2*t/(t_2 + t) = t/(1 + t/t_2) , 
```
    Calculate the sidereal month and DISPLAY calculation and the answer. Does it agree with the accepted value given above to 3 or more digits?
    Answer:
  End of Task
- Task 14: Calculating the Sidereal Lunar Month from Kepler's 3rd Law:
  The Newtonian Kepler's 3rd law is
```
     P = 2*π*sqrt[a**3/(G(m_1+m_2))]  ,
     
```
  where P is orbital period, "a" is the semi-major axis (AKA mean orbital radius) of the relative orbit (i.e., of one body relative another and NOT relative to the mutual center of mass), G is the gravitational constant G = 6.67408(31)*10**(-11) (MKS units), and m_1 and m_2 are the masses of the two bodies in the two-body system (see also Wikipedia: Standard gravitational parameter: Two bodies orbiting each other and Goldstein et al. 2002, p. 102). If m_1 >> m_2, the formula reduces to the approximate formula
```
    P = 2*π*sqrt[a**3/(G*m_1)]  .
    
```
  Students often find it very hard to calculate the orbital period using this formula. In fact, when they try to do so in ONE nonstop calculation on a calculator, the probability of going WRONG approaches 100 %---usually the order of operations is somehow mixed up.
  For example, when they try to calculate the sidereal month in DAYS given the relevant data in List: Earth-Moon-System Facts above (also at local link / general link: moon_facts.html): i.e., the gravitational constant, the Earth mass, and Moon mean orbital radius.
  Sub Tasks:
  1. Below we give three procedures for such a calculation. Read over ONE of the three procedures.
    Procedures:
    1. Do the calculation on a calculator one step at a time using the approximate Newtonian Kepler's 3rd law formula. First find x1 = a**3 = (384784*10**3 m)**3. Then find x2 = x1/G = x1/(6.67408*10**(-11) MKS), then x3 = x2/M_⊙ = x2/(5.9722*10**24 kg), then x4 = sqrt(x3), then x5=2*π*x4*( 1 day / 86400 s) ≅ 27.5 days.
    2. Do the calculation with a small computer code using some computer language: e.g., fortran. For example:
```
      print*
      print*,'Sidereal Month calculation using'
      print*,"the Newtonian Kepler's 3rd law in a Fortran program."
      pi=3.14159265358979323846264338327950288419716939937510e0_np
!              ! http://en.wikipedia.org/wiki/Pi#Approximate_value
      g=6.67408e-11_np    ! gravitational constant
      a=384784.e+3_np     ! Moon orbital radius in meters
      xm1=5.9722e24_np    ! Earth mass in kilograms
      xm2=7.342e22_np     ! Moon mass in kilograms
      x1=a**3 ; x2=x1/g ; x3=x2/(xm1+xm2) ; x4=sqrt(x3)
      x5=2.0_np*pi*x4*(1.0_np/86400.0_np)                       ! From multiple steps.
      x6=2.0_np*pi*sqrt(a**3/(g*(xm1+xm2)))*(1.0_np/86400.0_np) ! From one step.
!            Where we have used the exact Newtonian Kepler's 3rd law formula.
      x7=2.0_np*pi*sqrt(a**3/(g*xm1))*(1.0_np/86400.0_np)       ! From one step with the approximate
!                                                               !   Newtonian Kepler's 3rd law formula.
      print*,'x1,x2,x3,x4,x5,x6,x7'
      print*,x1,x2,x3,x4,x5,x6,x7
! 5.69706290776023039979E+0025 8.53610221597618008718E+0035 141194818992.52979988 375758.99056779705995
!         27.325964914076566062         27.325964914076566062         27.493419442226445430
      write(*,'(4e14.6,4x,3f10.6)') x1,x2,x3,x4,x5,x6,x7
!   0.569706E+26  0.853610E+36  0.141195E+12  0.375759E+06     27.325965 27.325965 27.493419
      xacc=27.321661547e0_np  ! The accepted sidereal month value (J2000).
      print*,'The calculated sidereal month in days is ',x6                ! 27.325964914076566062 days
      print*,'The calculated approximate sidereal month in days is ',x7    ! 27.493419442226445430 days
      print*,'The accepted value is ',xacc                                 ! 27.321661547 days
      print*,'The relative error in the exact calculation ',(x6-xacc)/xacc ! 1.59383965798743016043E-0004
      print*,'The relative error in the appr. calculation ',(x7-xacc)/xacc ! 6.36140352690538626232E-0003
        
```
      One can see that the exact formula is accurate to 4 digit places and ∼ 0.015 %, but the approximate formula is accurate to only 2 digit places and ∼ 0.63 %.
      Why is the exact formula NOT exactly correct? It is exact for an ideal gravitationally-bound 2-body system. The real Earth-Moon system is affected by astronomical perturbations: most importantly gravitational perturbations.
    3. Do calculation using approximate 2-digit arithmetic like so:
```
    P = 2*π*sqrt[a**3/(G*m_1)]  ! Using the approximate Newtonian Kepler's 3rd law.
      = 2*π*sqrt[(384784*10**3 m)**3/(6.67408(31)*10**(-11)*5.9722(6)*10**24 kg)] with all digits

      = 6.3*sqrt[(4*10**8)**3/(6.7*10**(-11)*6*10**24)]  rounding off to ∼ 2-digit values
      = 6.3*sqrt[6*10**25/(4*10**14)]
      = 6.3*sqrt(1.5*10**11) = 6.3*sqrt(15*10**10)
      = 6.3*4*10**5 = (25*10**5 s)*(1 day/(0.9*10**5 s))
      = 27 days
    
```
      which is correct to 2 digits.
  2. Have you read over ONE of the procedures above and understood it? Y / N
  End of Task
- Task 15: Werewolf:
  My children beware, the Werewolf transforms on the night of the:
  End of Task
- Task 16: Lunar Phase Simulator Questions:
  Sub Tasks:
  1. You complete this task using the NAAP applet: lunar phase simulator shown in the applet figure below (local link / general link: naap_lunar_phase.html). EVERYONE in the group must do the task for themselves.
  2. Push all the buttons. Do they all do something. Y / N
  3. What time of the solar day (using the time's special name, NOT a clock reading) is it when the humanoid is at the top/left/bottom/right? __________________________
  4. Why are the sun rays shown as parallel when we know that they actually diverge coming from the Sun?
    Answer:
  5. At first crescent, the Moon is (north / south / east / west) of the Sun on the sky. ___________
  End of Task
- Task 17: Lunar Phase Problem Examples---What You've Been Waiting For:
  In this task, we study lunar phase problems and study 3 examples of them.
  Sub Tasks:
  1. Read over the Moon Phase Calculator Diagram in the figure below (local link / general link: moon_phases_calculator.html).
    Have you done so and understood it? Y / N
  2. Now study the following 3 examples of lunar phase problems:
    1. The Moon is full and it is sunset. Where is the Moon on the sky?
      Phase and time are the knowns. Location on the sky is the unknown.
      A glance at the Moon Phase Calculator Diagram below (local link / general link: moon_phases_calculator.html) allows us to find the answer.
      The Moon must be on the eastern horizon. It is just rising. It is in opposition to the Sun as it must be when it is full.
      If the time were midnight, then the Moon would be transiting the meridian.
    2. The Moon is in the eastern sky at sunrise. What is its phase?
      Time and location on the sky are knowns. Phase is the unknown.
      A glance again at the Moon Phase Calculator Diagram below (local link / general link: moon_phases_calculator.html), shows us where eastern direction on Earth is at sunrise.
      Then, clearly, Moon must be a waning crescent.
    3. The Moon is half-full at 1st quarter moon and is transiting the meridian. What time of day is it?
      Location in sky and phase are knowns. Time of day is the unknown.
      We glance again at the Moon Phase Calculator Diagram below (local link / general link: moon_phases_calculator.html). It must be sunset.
      If the Moon was on the eastern horizon, it would be noon.
  End of Task
- Task 18: Lunar Phase Problems:
  Determine best answer for --- lunar phase / location in the sky / time of solar day --- for the following sub tasks.
  You will probably need Moon Phase Calculator Diagram shown in the figure above (local link / general link: moon_phases_calculator.html.html). But with a little practice, the answer usually just leaps into your mind.
  Sub Tasks:
  1. At what time does the full moon rise in the east? ___________________
  2. At what time does the new moon transit meridian? ____________________
  3. Where is the waxing gibbous moon in the sky at midnight? _______________________________
  4. At what time does the 1st quarter moon transit meridian? ____________________
  5. Which crescent moon is in the western sky at sunset? ____________________
  6. Where in the sky is the new moon at sunset? _______________________________
  7. At what time will all possible waning moon phases be BELOW the horizon? ____________________
  8. If it is midnight and the Moon is on the eastern horizon, what is the lunar phase? ____________________
  9. It is about 6:00 am and the Moon is transiting the meridian. What is the lunar phase? ____________________
  10. It is about 6:00 am and the Moon is a 1st quarter moon. Where is the Moon? ________________________________________
  End of Task
- Task 19: Axial Rotation Period and Lunar Day:
  Sub Tasks:
  1. Read over the subsection The Moon is Tidally Locked to the Earth above (local link / general link) including the 2 figures at local link / general link: tidal_locking_moon.html.html and local link / general link: moon_lunar_phases_animation.html.html.
    Have you done so? Y / N
  2. Now how long is the Moon's axial rotation period (relative to the approximate inertial frame of the fixed stars) and the lunar day (which is NOT the same thing as the axial rotation period)? HINT: This is easy if you think about it the right way.
    Answer:
  End of Task
- Task 20: Giant Impactor:
  Sub Tasks:
  1. Read the figure below (local link / general link: moon_formation.html) on the giant impact hypothesis? Have you read it? Y / N
  2. In the theory, the hypothetical giant impactor had a mass of order that of ____________ .
  3. In the theory, the Moon formed mainly from specifically the _____________ material from the Earth and the impactor.
  End of Task
- Task 21: Lunar Geology Tidbits:
  Sub Tasks:
  1. Read again the Moon-map figure above (local link / general link: moon_map_side_near.html). Have you read it? Y / N
  2. The lunar surface is divided in lunar highlands mostly older than 4 Gyr and ____________________________ mostly younger than 4 Gyr.
  3. After the maria, the most obvious lunar features are the _________________________ due to impact events.
  4. Read 2 figures below (local link / general link: moon_regolith_pete_conrad.html; local link / general link: space_weathering.html). Have you read them? Y / N
  5. Most airless worlds in the Solar System and, by undoubted hypothesis, throughout the observable universe have their surfaces pounded down to regolith by ___________________.
  End of Task

Lab 4: The Moon

Group Number/Name:

Name:

Partner Names:

Favorite Report: Y / N

illumination at 9 pm PDT = illumination at 8 pm PST

= 0.24 + (20/24)(0.34-0.24) = 0.24 + (7/8)0.10 ≅ 0.24 + 0.9 = 0.33 ,

Lab 4: The Moon

Group Number/Name:

Name:

Partner Names:

Favorite Report: Y / N

illumination at 9 pm PDT = illumination at 8 pm PST

= 0.24 + (20/24)*(0.34-0.24) = 0.24 + (7/8)*0.10 ≅ 0.24 + 0.9 = 0.33 ,

= 0.24 + (20/24)(0.34-0.24) = 0.24 + (7/8)0.10 ≅ 0.24 + 0.9 = 0.33 ,