Task Master:
All the Tasks are linked here so that you can find them in the context of
the lab narrative---which is useful
when completing your Report Form
for IPI
or just working through the Tasks
for RMI.
- Task 1: Planetary Configuration Definitions.
- Task 2: Planetary Configurartion Simulator Questions.
- Task 3: Angle Measurement with a Protractor
(IPI only).
- Task 4: Solar System Diagrams Made Using TheSky
(IPI only).
- Task 5: Measuring Elongations
(IPI only).
- Task 6: The Ptolemaic System Simulator.
- Task 7: The Ptolemaic System and Uniqueness.
- Task 8: Inferior Planet Oscillation and Ptolemy.
- Task 9: Copernicus Questions.
- Task 10: Copernicus' Form of the Universe.
- Task 11: Scientific Theories.
- Task 12: The Planetary Orbit Simulator.
- Task 13: The Planetary Orbit Simulator and a Logarithmic Plot.
- Task 14: The Doppler Effect Explicated a Little.
- Task 15: The Exoplanet Radial Velocity Simulator.
Optional at the discretion of the
instructor.
- Task 16: The Exoplanet Transit Simulator.
Optional at the discretion of the
instructor.
- Task 17: Exoplanet Mean Orbital Radius and Year of Discovery.
Optional at the discretion of the
instructor.
- Task 18: Exoplanet Mean Orbital Radius and Orbital Period.
Optional at the discretion of the
instructor.
- Task 19: Print Sky Map and Observable Planets.
- Task 20: Planet Observations
(IPI only).
End of Task
- Task 1: Planetary Configuration Definitions:
Complete the following short
definitions
in complete sentences in your own words.
Read the definition or explanation from some source,
think about what it means, and then formulate your own version.
Sub Tasks:
- Apparent retrograde motion is:
- A conjunction is:
- The ecliptic is:
- Elongation is:
- A greatest elongation is:
- Inferior
and superior conjunctions are:
- Inferior and superior planets are:
- An opposition is:
- A
planetary configuration
is:
- A quadrature is:
- A syzygy is:
End of Task
- Task 2: Planetary Configuration Simulator Questions:
Complete this task using the
planetary configuration simulator
shown in the applet figure below
(local link /
general link: naap_planetary_configurations.html).
in the group must do this
task for themselves.
Sub Tasks:
- Push all the buttons to see what they do.
Did you do this?
Y / N
- Can you see apparent retrograde motion
in the lower simulation panel?
Y / N
- Can you make the simulator show the elongation
angles?
Y / N
- Can you make the target planet an
inferior planet?
Y / N
- Can you make the target planet orbit at
exactly 1 AU if the observer is on Earth?
Y / N
End of Task
- Task 3: Angle Measurement with a Protractor
(IPI only):
EOF
End of Task
- Task 4: Solar System Diagrams Made Using TheSky
(IPI only):
Sub Tasks:
- Launch TheSky
(TheSky6,
TheSkyX as your instructor
directs).
-
For the TheSky6, go
Toolbar/File/AST105 which is probably
unnecessary
since AST105 should be the normal setting, but sometimes people leave
TheSky6 in funny modes.
-
Set the date to today's date & time:
2025 August 17, Sunday
4:05:52 am
Go Toolbar/Data/Time.
-
To view the Solar System appropriately,
go Toolbar/View/3D Solar System Model.
Then check out the
List of Tricks for TheSky:
Solar System Tricks (i.e., item 18)
which tells you how to do some of the things we have to do tonight.
- We a view of the Solar System
the north end of the ecliptic axis
pointing straight out of the screen:
i.e., we want
the ecliptic plane (i.e., the plane
of the Earth's orbit) perpendicular to the
line-of-sight with
eastward being
counterclockwise.
Usually, the 3D Solar System Model will just come up in this orientation.
If NOT, use the
Tricks (item 18)
to find out how to get it.
-
The direction of the red line is the vernal equinox which
is the zero point of the
right ascension (RA) in the
equatorial coordinate system.
-
Zoom in to see the
inner Solar System
out to Mars.
If some inner Solar System
planets are turned off,
you must turn them on using the
button menu with Display Explorer.
See
List of Tricks for TheSky:
Solar System Tricks (i.e., item 18.1).
- Go Toolbar/File/Print Preview.
Try to get the Mars
orbit as large as possible and still be all
visible in the Preview---you'll have to go back to
TheSky
to adjust the size.
The larger the Mars
orbit, the easier the measurements on the
printout will be.
- Go Toolbar/File/Print Preview/Print
to get a printout of the
Solar System diagram.
Get one printout per group to append to
the
favorite report form---unless your
instructor
asks for every group member do to a
Solar System diagram.
If you don't want to print after seeing the Preview, go
Toolbar/Close.
- Now zoom out to show
Jupiter
and Saturn,
click off
Mercury,
Venus,
and Mars, but NOT
Earth.
To click off a planet, go
Toolbar/View/Display Explorer/expand Solar System/expand Planets/click off planet.
- Get a printout of this Solar System diagram following the
same procedure as for the first one.
- We probably won't use
TheSky
again tonight,
but you can leave it open just in case.
But when you do close
TheSky,
do NOT save changes.
End of Task
-
Task 5: Measuring Elongations
(IPI only):
Sub Tasks:
- If the astronomical objects are NOT named
already, write in their names (i.e., label the Earth,
Sun
and all the shown planets)
on your Solar System diagrams.
- Draw lines from the
Earth to the Sun
and all the shown planets
and extend the lines well beyond the astronomical objects
so that you can measure the elongations
to the planets easily with
a protractor.
- Remember elongation is
measured
east/west
from the
Earth-Sun line
from 0° to 180°.
- Measure the
elongations
of the planets
and put the elongation values
on the diagrams showing to which angle they apply as best you can.
- You should attach the diagrams to the
favorite report form---or, if
every student printed diagrams as requested by the
instructor,
to every group member's report form.
- For today's date (see Date & Time),
complete the table below
(local link /
general link: Table: Elongations and Nearest Planetary Configurations).
By nearest
"planetary configuration",
we mean the
planetary configuration
nearest to today's
elongation just approximately.
You'll need to know that the
greatest elongations
for Mercury and
Venus are, respectively, 18--28°
and 45--47°
(see Wikipedia: Elongation).
There is a range of greatest elongations
since the orbits are NOT exact circles.
_______________________________________________________________________________________
Table: Elongations and Nearest Planetary Configurations:
For today, right now.
_______________________________________________________________________________________
Planet Elongations Nearest Planetary Configuration
(degrees,E/W) (e.g., opposition, quadrature, etc.)
_______________________________________________________________________________________
Mercury
Venus
Mars
Jupiter
Saturn
_______________________________________________________________________________________
End of Task
-
Task 6: The Ptolemaic System Simulator:
Complete this task using the
Ptolemaic System Simulator
shown in the applet
figure below
(local link /
general link: naap_ptolemaic_system_simulator.html.html)
after this task.
in the group must do the task for themselves.
Sub Tasks:
- Push all the buttons to see what they do.
Did you do this?
Y / N
- Can you see apparent retrograde motion
in the 2 simulation panels for a
superior planet? Y / N
- Can you make simulator show the motion of an
inferior planet?
Y / N
- Can you see apparent retrograde motion
in the 2 simulation panels for an
inferior planet?
Y / N
- Can you identify your
zodiac constellation
by using the
NAAP Applet: Seasons and the Zodiac Simulator?
Y / N
- Can you change the epicycle size and
the equant eccentricity,
and show the
Earth-Sun line
and the
epicycle center-planet
line?
Y / N
End of Task
-
Task 7: The Ptolemaic System and Uniqueness:
The Ptolemaic system
was NOT the uniquely good geocentric
epicycle system---many roughly equally good
geocentric epicycle systems were developed in the
centuries
after Ptolemy (c.100--c.170 CE).
After reading the caption with
Ptolemaic System Simulator
(which is given above), discuss
whether or NOT Ptolemy should
have been aware of the non-uniqueness problem of
geocentric
epicycle systems
and what might a modern scientist
conclude about the geocentric
epicycle theory
from the non-uniqueness problem.
Remember that the Ptolemaic system
was worked out in great detail by Ptolemy,
and so he spent a lot of time devising its particular
epicycle orbits.
Answer:
End of Task
-
Task 8: Inferior Planet Oscillation and Ptolemy:
Was the fact that
the inferior planets
exhibit an apparent oscillation around the Sun's position on the
sky (see the figure above
(local link /
general link: ptolemy_system.html)
and
the Ptolemaic System Simulator
in the applet figure below
(local link /
general link: naap_ptolemaic_system_simulator.html.html)
a clue to
good old Ptolemy? Discuss.
HINT: You might consider what happens in the
Tychonic system
and the Copernican system.
Answer:
End of Task
-
Task 9: Copernicus Questions:
Sub Tasks:
- Approximately how long after Ptolemy was
the lifetime of
Copernicus? _______________
- What is the main difference between the
Ptolemaic system
and the heliocentric solar system?
Answer:
- Discuss why would people in the
16th century found the
heliocentric solar system
hard to accept.
Remember, they thought motion and rest were absolutely different states and
thought of the Heavens
as being unchanging and eternal unlike the
Earth.
Answer:
End of Task
- Task 10: Copernicus' Form of the Universe:
Sub Tasks:
- Read the figure below
(local link /
general link: copernican_system.html)
which is from Copernicus'
own book on heliocentric solar system.
Have you read it? Y / N
- Since heliocentrism gave the
relative radii for the
planets
(which now included the
Earth),
the structure of the Solar System
was revealed to Copernicus:
... the chief thing, that is the form of the universe and the clear
symmetry of its parts.
This quote suggests that Copernicus
thought that the deduced structure of the Solar System
(which he thought of as being the whole
universe or
whole cosmos)
was the main argument for heliocentrism.
Unfortunately, Copernicus never makes that
completely explicit it seems.
He certainly thought of it as a major argument.
Retrospectively, it clearly is the main argument.
Now Copernicus could NOT
measure absolute distances beyond the
Moon.
No one could until the 17th century
(see Wikipedia: Astronomical unit: History).
So how could Copernicus
get the correct order and correct relative orbital radii of
planets or as he put it
"form of the universe".
HINT: The short answer is expected.
Answer:
End of Task
- Task 11: Scientific Theories:
From the heliocentric solar system model,
Nicolaus Copernicus (1473--1543) was able to
predict the mean orbital radii
of the planets in their
orbits around the
Sun.
On the other hand,
from the (geocentric)
Ptolemaic system,
Ptolemy (c.100--c.170 CE)
was NOT able to predict the locations of the
planets in
space, NOT even their
order going outward from the Earth.
He was able to make such predictions with
extra hypothetical as detailed in his
Planetary Hypotheses---but let's
NOT consider those predictions and hypothetical
since they go beyond the basic
Ptolemaic system.
Discuss which scientific theory is better---the
heliocentric solar system model or
the Ptolemaic system---from
the point of view of modern science,
but without knowing which is right.
Answer:
End of Task
- Task 12: The Planetary Orbit Simulator:
Complete this task using the
planetary orbit simulator
in the applet figure below
(local link /
general link: naap_planetary_orbit_simulator.html)
after this task.
in the group must do the task for themselves.
Sub Tasks:
- First, read the subsection
Kepler's 3 Laws of Planetary Motion Illustrated
including 2 figures above
(local link /
general link: kepler_1st_2nd_law.html;
local link /
general link: kepler_2nd_law.html)
illustrating
Kepler's 3 laws of planetary motion.
Have you read it? Y / N
- Push all the buttons of
the planetary orbit simulator
to see what they do.
Did you do this?
Y / N
- Start the animation. Can you find the allowed range of eccentricity?
Y / N
- Can you make the simulator show the planets,
orbits,
and orbit names out to
Mars? Y / N
- With parameters set for
Mercury (remember to click OK) and
using the Kepler's 1st law tab,
can you show the empty focus,
the semi-major axis,
the semi-minor axis,
the geometric center,
and the radial lines? Y / N
- Using the Kepler's 2nd law tab,
can you see or hear equal areas being swept out in equal times qualitatively?
There's no real right answer---just make your best judgment.
If there's no speaker, you can't hear the ticking sound.
Y / N / Maybe
- Using the Kepler's 3rd law tab,
can you make all the planets
(including ex-planet Pluto) show up on the
logarithmic plot?
HINT: Push all the buttons.
Y / N
- Does the logarithmic plot show a line?
Y / N
- With parameters set for
Mercury (remember to click OK) and
and using the
Newtonian features tab, can you make the velocity
and acceleration
vectors appear?
Y / N
- What is the range of Mercury's
velocity? ___________________________
End of Task
- Task 13: The Planetary Orbit Simulator and a Logarithmic Plot:
Sub Tasks:
- Read the above subsections
Kepler's 3rd Law,
Power Laws and Logarithmic Plots,
and Logarithmic Plots in General
including their embedded figures.
Have you read them?
Y / N
- Go back to the
planetary orbit simulator
in the applet figure above
(local link /
general link: naap_planetary_orbit_simulator.html).
Using the Kepler's 3rd law tab,
can you make all the planets
(including ex-planet Pluto) show up on the
logarithmic plot?
Y / N
What is the slope of the
curve on the plot? _________________
End of Task
- Task 14: The Doppler Effect Explicated a Little:
In this lab, we do NOT want to expand much on the
Doppler effect/shift, but
a little explication is needed to understand it for our purposes.
Sub Tasks:
- Read the subsection above
The Doppler Effect
(local link /
general link:
The Doppler Effect).
Have you read it?
Y / N
- Watch all the
Doppler effect videos
below
(local link /
general link:
Doppler effect videos).
Have you watched them?
Y / N
End of Task
- Task 15: The Exoplanet Radial Velocity Simulator:
Complete this task using the
NAAP: Exoplanet Radial Velocity Simulator
shown in the figue below
(local link /
general link: naap_radial_velocity_simulator.html).
in the group must do the task for themselves.
Sub Tasks:
-
- First, read the subsection
The Discovery of Exoplanets by Doppler Spectroscopy above
(local link /
The Discovery of Exoplanets by Doppler Spectroscopy)
Have you read it? Y / N
- Push all the buttons of
the NAAP: Exoplanet Radial Velocity Simulator
to see what they do.
Did you do this?
Y / N
- Can you start the animation,
change the animation speed,
and show multiple views of the planetary system?
Y / N
- What happens to the radial velocity
as the inclination is increased from
0° to 90°?
Answer:
- Does the radial velocity curve change
with longitude of observation?
Y / N
- How does changing the stellar mass affect
the overall radial velocity?
Why does it have this effect?
Answer:
- How does changing the planet mass affect
the overall radial velocity?
Why does it have this effect?
Answer:
- How does changing the planet
mean orbital radius (AKA semi-major axis)
affect
the overall radial velocity?
Why does it have this effect?
Answer:
- How does changing the planet
eccentricity
affect
the overall radial velocity?
Why does it have this effect?
Answer:
- Can you show the simulated measurements?
Y / N
- Can you change the signal noise?
Y / N
- More signal noise should make the
observations worse?
Y / N
End of Task
- Task 16: The Exoplanet Transit Simulator:
In the
transit method for
the discovery of exoplanets,
one just observes the light curve of
a star.
Dips in the light curve of the right kind
show that planets are
transiting the
star and partially
eclipsing it.
Only stars with
inclination near 90°
will exhibit planet
transits.
EVERYONE in the group must do this task for themselves.
Sub Tasks:
- Push all the buttons on
NAAP: Exoplanet Transit Simulator
shown in the figure below
(local link /
general link: naap_exoplanet_transit_simulator.html)
this task to see what they do. Did you do this?
Y / N
- What happens as you change the planet mass?
Answer:
- What happens as you change the planet radius?
Answer:
- What happens as you change the
mean orbital radius (AKA semi-major axis)
with inclination NOT equal 90°?
Answer:
- What happens as you change the
mean orbital radius (AKA semi-major axis)
with inclination equal 90°?
Answer:
- What happens as you change the
stellar mass?
Answer:
- What happens as you change the
inclination?
Answer:
- Can you show the simulated measurements?
Y / N
- Can you change the signal noise?
Y / N
- More signal noise should make the
observations worse?
Y / N
End of Task
- Task 17: Exoplanet Mean Orbital Radius and Year of Discovery:
Sub Tasks:
- Click The Extrasolar Planets Encyclopaedia: Diagrams.
- Select x axis
semi-major axis (AKA mean orbital radius)
and log scale.
- Select y axis
year of discovery
and linear scale (i.e., non-log scale).
- What kind of plot is shown:
linear scale plot,
semi-log plot,
log-log plot?
______________________________
- What is the
semi-major axis (AKA mean orbital radius)
range for known exoplanets to
order of magnitude?
For example, 10**(-1) to 10**2 AU.
Answer: ______________________________
- Discounting the 1988 discovery (which was a tentative
and only confirmed later)
and 1992 discoveries
(which were pulsar planets
which orbit pulsars),
the first exoplanet discovered
was in ________________ .
- Do most discovered exoplanets
have mean orbital radii less than 1 AU?
Yes / No / Maybe
- As Time Goes By (1931),
this plot is likely to grow into a pointy-bottomed column (solid black at the center and speckly at the
edges). Yes / No / Maybe
End of Task
- Task 18: Exoplanet Mean Orbital Radius and Orbital Period:
Sub Tasks:
- Click The Extrasolar Planets Encyclopaedia: Diagrams.
- Select x axis
semi-major axis (AKA mean orbital radius)
and log scale.
- Select y axis
orbital period
and log scale.
- What kind of plot is shown:
linear scale plot,
semi-log plot,
log-log plot?
______________________________
- The fact that most points on
the The Extrasolar Planets Encyclopaedia: Diagrams
log-log plot lie nearly on a straight line agrees
approximately with
the dynamical Kepler's 3rd law
which has the formula
P=[2π/(GM)**(1/2)]*R**(3/2) ,
where P is orbital period,
M is the parent star
mass (assumed much larger than the
planet
mass),
gravitational constant G = 6.67430(15)*10**(-11) (MKS units),
and
R is the mean orbital radius
(AKA the semi-major axis).
On the log-log plot, one gets
the linear relationship between logarithmic period and logarithmic radius
log(P)=(3/2)*log(R) + constant .
What is the slope of the line
on a log-log plot of
the dynamical Kepler's 3rd law?
HINT:
Reread subsection
Power Laws and Logarithmic Plots
above
(local link /
general link: Power Laws and Logarithmic Plots).
______________________________
- The set of points on the
The Extrasolar Planets Encyclopaedia: Diagrams
log-log plot
is a band, NOT a line because 1) ________________________________ ,
2) ________________________________________ .
End of Task
-
Task 19: Print Sky Map and Observable Planets:
Sub Tasks:
- IPI only:
Print out the sky map figure below
(local link /
general link: sky_map_current_time_las_vegas.html)
following the
instructions in the figure and updating the time to your approximate observing time if necessary.
- IPI only:
Print out one sky map per group
or per group member as your instructor directs.
- IPI only:
Did you succeed in getting a printout of the
sky map? Y / N
- RMI only:
Go to
Sky Maps by Ordinal Date
for your observing day and
print out the white background sky map.
You will have update the
Universal Time (UT) to your
observing time.
For how to do this, see
General Task: Naked-Eye Observations.
- The
planets
on the sky map are identified by
the planet symbols---the
planet symbols
are elucidated in the figure below
(local link /
general link: sky_map_current_time_las_vegas.html)
- What planets can we possibly
see tonight (or your observing night) because
they are above the horizon
NOT counting Earth?
Answer:
- What planets can we see for sure tonight
(or your observing night)
because they are sufficiently high in the sky,
they are sufficiently bright,
and the weather permits?
Answer:
- RMI qualification:
Since you are an RMI student,
you can wait a few days at least for a night with good enough
weather for the observing
planets.
- Read over the planet
write-ups
in the subsection Observable Planets below
(local link /
general link: Observable Planets)
about the observable and possibly observable
planets.
Have you read them? Y / N
- RMI only:
Do
General Task: Naked-Eye Observations at link
General Task: Naked-Eye Observations
and in particular look for the
observable planets
that can be seen with the
naked eye.
End of Task
- Task 20: Planet Observations
(IPI only):
Sub Tasks:
- Read over
subsection Celestron C8 Telescope Review
above
(local link /
general link: Celestron C8 Telescope Review)
Have you read it? Y / N
- Print out as many
field of view (FOV) diagrams
(see below) as your
instructor
requires and append them to the
Report Form as your
instructor directs.
The circle on the diagram is the
FOV area.
- Take the diagrams outside with you with something solid to hold the diagrams on when you sketch on them.
- Now observe the planets
your instructor
chooses and draw diagrams of those he/she chooses with
whatever focal length
eyepieces he/she chooses.
- Before you use an eyepiece
smaller than the standard 40-mm eyepiece
you have to center the planet
in the FOV of
standard 40-mm eyepiece.
Then you switch to the smaller eyepiece.
- For the sketches of the FOV,
sketch the planet and accompanying detail: e.g.,
moons,
band structure,
planetary rings,
and stars in the
FOV on the
FOV diagram.
- Outside the circle of the FOV area,
mark down the
eyepiece focal length,
telescope magnification,
and the FOV diameter.
See Table: C8 Telescope Specifications for Available Eyepieces.
- Also outside the circle of the FOV area,
label the sky (i.e.,
celestial sphere) directions:
north,
south,
east,
west.
Remember the
C8 telescopes
does a point inversion
and the star diagonal
does an plane reflection
through the line perpendicular to its symmetry plane.
So you can approximately figure out
north,
south,
east,
and
west.
- Take a cell phone image of the
observed planet for fun.
There are no marks whether you do this or NOT.
End of Task
