Slide 2 Bell Work 9-14-15 Do you think constellations would look
similar or different from Mars? WHY?! Slide 3 Scale Scale
Description 4 Through independent work beyond what was taught in
class, you could: investigate the location of seasonal
constellations in the local sky. predict location of constellations
at future times. determine the celestial equator, latitude and
position of the Pole Star for a given position on the Earth.
determine the distances of stars in a given constellation to each
other and to Earth. 3 You will be able to: describe and apply the
coordinate system used to locate objects in the sky. distinguish
the various methods of measuring astronomical distances and apply
each in appropriate situations. 2 You will be able to: determine
the meaning of symbols, key terms, and other astronomy specific
words and phrases as they are used in context to relevant topics
label diagrams with degree measurements describe how or why
different units of measurement are needed for distances in space 1
You will be able to label diagrams with degree measurements list
the different units of measurement needed to measure distances in
space Slide 4 Please take out your constellation lab from Fri. Open
your science journal to your constellation notes. Take the tape
from the lab boxes, and you can tape your lab atop your notes Slide
5 Astrolabe The astrolabe was invented in Greece either by
Hipparchus, a 2nd century B.C. astronomer, or Apollonius of Perga,
a 3rd century B.C. mathematician. For many centuries, it was used
by both astronomers and navigators, and especially by the 15th
century explorers who used it to determine latitude, longitude, and
time of day. Slide 6 Slide 7 Copy this in the top half of your
journals right page ObjectAngle of Altitude #1degrees #2degrees
#3degrees #4degrees Slide 8 Copy this on the top half of your
journals left page Sun MeasurementDateTimeAngle of Altitude
#1Monday 9-14degrees #2Monday 9-21degrees #3Monday 9-28degrees
#4Monday 10-5degrees Slide 9 Copy this on the bottom half of your
journals left page Moon MeasurementDateTimeAngle of Altitude
#1Monday 9-14degrees #2Monday 9-21degrees #3Monday 9-28degrees
#4Monday 10-5degrees Slide 10 To become familiar with how an
astrolabe works, practice measuring the altitude (angular height)
of trees or buildings. To make a proper measurement, look at the
top of the object through the straw. Have someone read the altitude
in degrees from the side of the astrolabe. The point where the
string crosses the scale is the proper measurement. Practice using
your astrolabe by measuring and recording another tree or building
of a different height. Now that you have an understanding of how an
astrolabe works, you can use it to measure the motion of the Sun.
Slide 11 Because it is harmful to look directly at the Sun, a new
method for measuring the Sun's altitude must be used. Hold the
astrolabe so that the straw points in the direction of the Sun. Do
not look through the straw. Aim the straw so that you see the
shadow of the straw on your hand. Move the straw slightly until a
small circle of light forms on your hand. The straw is now pointing
directly at the Sun. Ask someone to read the Sun's altitude (in
degrees) where the string crosses the scale. Take note of the time
of day the reading was made. One day a week, at the same time each
day, measure the altitude of the Sun with your astrolabe. Make
three consecutive measurements and record them in the chart
provided. Be sure to include the date. As the weeks progress, look
at your measurements of the Sun's altitude. Can you detect a
change? Is the altitude increasing or decreasing? Is there a
pattern of change? How can you explain these changes? Slide 12
Todays question: How can we measure distances and direction in the
sky? Some words I need to know: Zenith, Meridian, Altitude,
Azimuth, Nadir, Start on the bottom of the right side of your
journal. The Celestial Sphere Slide 13 Celestial Sphere definition:
The huge imaginary sphere on which all the objects in the sky were
once considered attached. (was also thought to be centered on
earth) Though its not actually the case, its convenient for
describing locations of objects in the sky. (paraphrase this)
Similar to an upside-down bowl covering the earth Celestial Sphere
Slide 14 Slide 15 1.3 The Obvious View The celestial sphere: Stars
seem to be on the inner surface of a sphere surrounding the Earth
They arent, but we can use two-dimensional spherical coordinates
(similar to latitude and longitude) to locate sky objects Slide 16
Based on the point of view of the observer It works if you are near
somebody Altitude measurement of height in the sky 0-90 Azimuth
measurement around the horizon 0-360 Horizontal Coordinate System
Slide 17 Slide 18 Slide 19 Slide 20 Altitude of Sun 606647 Azimuth
of Sun 134202246 time 11am1pm3pm Example - Sun Slide 21 Altitude
degrees - height Azimuth degrees - compass direction Remember:
Slide 22 1 Slide 23 2 Slide 24 3 Slide 25 4 Slide 26 Put in a
numeric answer What would the azimuth be for the flag? Slide 27
Also put in a numeric answer What about for Worm? Slide 28 This is
why it works great for people near each other, but not so much for
people far away from each other (opposite sides of the earth) What
would the azimuth and altitude be for the projector mounted on the
ceiling? Slide 29 similar to the longitude-latitude on the Earth's
surface. Fixed with respect to the stars (preferred by
astronomers). Equatorial coordinate system Slide 30 Slide 31 Slide
32 Slide 33 Slide 34 Slide 35 2011 Pearson Education, Inc. Slide 36
(1) Because the celestial sphere provides a natural means of
specifying the locations of stars on the sky. Celestial coordinates
are directly related to Earths orientation in space, but are
independent of Earths rotation. (2) Distance information is lost.
Slide 37 lines that run north-south on Earth are lines of longitude
and when projected onto the sky, they become lines of right
ascension. the stars were used to measure time in the past, so
right ascension (RA) is measured in terms of hours, minutes, and
seconds and increases in an easterly direction. lines that run
east-west on Earth parallel to the equator are lines of latitude
and when projected onto the sky, they become lines of declination.
Like the latitude lines on Earth, declination (dec) is measured in
degrees away from the celestial equator, positive degrees for
objects north of the celestial equator and negative degrees for
objects south of the celestial equator. Slide 38 Slide 39 Slide 40
Slide 41 Slide 42 Slide 43 Bottom of page 12 or 13: in 2-3
sentences, answer the question from the start of the activity using
information from your notes. summarize
