Key
Phys 102 Astronomy
Name ____________________
ECLIPSES & TIDES
1) In the Field Guide (pp. 359 – 364 & pp. 481 – 494 , determine the next total eclipse of the moon after
2/21/08 and total eclipse of the sun visible from the continental US
Aug. 21, 2017
Next US total solar eclipse _____________
Dec. 21, 2010
Next US total lunar eclipse _____________
2) Go to the NASA Eclipse page at http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html and find the
Decade Solar Eclipse table for the next US total eclipse. Click on each of the five live links for that
eclipse (going across the page) to find out what’s there … note what you find
Link Name
Information
1
2017 Aug 21
Diagram of globe showing the eclipse’s path across the oceans & US
2
18:26:40
Small animation of the moon’s shadow crossing the planet, Earth
3
total
Google map of eclipse path!
4
145
Catalog of Saros series 145, eclipses from 1/4/1639 – 4/17/3009
5
02m 40s
Path of Moon’s shadow across Earth (latitude & longitude) by minute
For the link that gives you a Google Map, zoom in and determine the street nearest the greatest eclipse
and the nearest village or town.
Rt. 624: CeruleanNearest Street ________________
Hopkinsville Rd.
Cerulean, KY
Nearest Town ________________
3) Go to the NASA Eclipse page at http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html and find the Lunar
Eclipse table for the next US total eclipse after 2/21/08. Click on both live links and see what you find.
Use the chart for this eclipse to fill out the bottom table … figure out meanings from the diagram!
Link Name
Information
1
2010 Dec 21
Diagram of Earth’s shadow showing how Luna will move through it
2
125
Catalog of Saros series 125, eclipses from 7/17/1163 – 9/9/2443
Time
Event Explanation
UT
EST
P1
05:27:43
12:27:43 am
The moon’s first contact with the penumbra
U1
06:32:17
1:32:17 am
The moon’s first contact with the umbra
U2
07:40:21
5:40:21 am
The moon completely within umbra, totality begins
Greatest
Eclipse
08:16:56
3:16:56 am
The moon most deeply into the shadow
EclipsesTides Solution.doc
Eclipses
9/28/2007
4) Below is a tide table for Portland, Maine. Determine the date of the highest and lowest high tide.
What are the phases of the moon on those dates (if it’s two days, choose the earlier).
10/27
Highest High Tide Date: ________
12:09 pm
Time: ________
Just past full
Moon Phase: ________________
10/19
Lowest High Tide Date: ________
5:17 am
Time: ________
Just past 1 ¼
Moon Phase: ________________
st
Enter the coordinates of Portland, Maine (43° 38.5’ N, 70° 18.5’ W) into Starry Night, go there and find
the moon at the dates and times of the highest and lowest high tides in Portland. List its altitude &
azimuth
Highest High Tide Moon Position:
-63°.77
Altitude ________
309.7°
Azimuth: ________
Lowest High Tide Moon Position:
-20°.07
Altitude ________
337.1°
Azimuth: ________
Do these make sense given the theory of tides covered in class today? Explain how!
The moon at the highest high tide, or spring tide, is just past full and
on the opposite side of the Earth at the time of high tide so the moon’s &
sun’s tidal forces are opposite, increasing the tides.
The lowest high tide, or neap tide moon is just below the horizon, and
will be rising about 5 hours, or a quarter of a day later … so it’s pulling about
perpendicular to the sun.
So the positions of the moon fit pretty well with the theory given how
complicated the tides actually are!
Page 2
EclipsesTides Solution.doc
Eclipses
Chart showing times & path of total solar eclipse on 8/21/17
Page 3
9/28/2007
EclipsesTides Solution.doc
Eclipses
Map showing location of greatest eclipse on 8/21/17
Page 4
9/28/2007
EclipsesTides Solution.doc
Eclipses
Chart showing times & path of total lunar eclipse on 12/21/10
Page 5
9/28/2007