THE SOUTHWORTH PLANETARIUM
207-780-4249   www.usm.maine.edu/planet
70 Falmouth Street   Portland, Maine 04103
43.6667° N                   70.2667° W 
Altitude:  10 feet below sea level
Founded January 1970
Julian Date:  2459265.18 
2020-2021:  XCIV


THE DAILY ASTRONOMER
Friday, February 19, 2021
Exploratorium XXVII:  Week 7 Quiz

We were somewhat eclipse-focused  this last week, save for Thursday when we prepared for the Perseverance Rover landing, which, we're happy to report, was successful.       (We're going to  devote Monday to answering eclipse questions.  Please send yours!)      This week's quiz is also focused primarily, but not solely, on eclipses.     


1. Electra and her brother ____________ killed their mother to avenge the death of their father _____________, who, years before,  had sacrificed his daughter _______________ in order to appease the goddess _______________.
a.  Eros; Hermes; Antigone; Athena
b. Theseus; Tyndareus; Medea; Hera
c. Orestes; Agamemnon; Iphigenia; Artemis
d. Bellerophon; Menelaus; Hermione; Aphrodite

2.  The moon's orbit is inclined by _________ degrees relative to the ecliptic.
a.  2.3
b. 5.1
c. 7.2
d.10.4 

3.  A partial lunar eclipse is one in which ___________________.
a. the moon doesn't enter the penumbra
b. the moon only partially enters the umbra
c. the moon remains fully immersed in the umbra for less than thirty minutes
d. none of the above

4.  Earth's shadow cone is approximately ________________ miles long.
a.  230,000 
b. 410,000
c. 675.000
d. 840,000

5.  The moon's orbit intersects Earth's at the ____________ node and the ______________ node.
a.  ascending; descending
b.  equinox; solstice
c.  alpha; omega
d.  90 degree; 180 degree

6.  The umbral magnitude of a lunar eclipse inidcates____________.
a. the percentage of the moon's face that enters the umbra
b. the percentage of the moon's angular diameter that enters the umbra
c. both a and b
d. neither a nor b 

7. The first eclipse in Saros 180 will occur on August 28, 2827.  Which of the following statements pertaining to this Saros cycle is/are true?
a.   the first eclipse will be a partial penumbral
b.  only the lower part of the moon's limb will pass through the penumbra during the first eclipse.
c.  the lunar eclipses in this Saros cycle will occur around the ascending node
d.  the second eclipse in this Saros cycle will occur in early September in the year 2845.  

8.   What happened to the men who ate the Lotus fruit?
a. they were turned into swine
b. they became invisible
c. they stopped caring about everything in their lives and wanted only to eat more fruit
d. they were turned into stone.

9. The amount of time separating successive full moons is called a _____________ month.
a. draconic
b. anomalistic
c. synodic
d. sidereal

10.  The last total lunar eclipse in the Saros 126 cycle occurred on ________________.
a. November 9, 2003
b.  October 28, 1985
c. October 18, 1967
d. October 7, 1949




ANSWERS
1. Electra and her brother ____________ killed their mother to avenge the death of their father _____________, who, years before,  had sacrificed his daughter _______________ in order to appease the goddess _______________.
c. Orestes; Agamemnon; Iphigenia; Artemis
Even those Orestes and Electra murdered their mother and her new husband to avenge their father's death, only Orestes was pursued by the Furies.

2.  The moon's orbit is inclined by _________ degrees relative to the ecliptic.
b. 5.1
We d0n't experience lunar and solar eclipses each month because the moon will generally be north or south of the ecliptic when the moon is full or new.

3.  A partial lunar eclipse is one in which ___________________.
b. the moon only partially enters the umbra
The November 19, 2021 lunar eclipse is technically a partial lunar eclipse because the moon doesn't entirely enter the umbra.  However, around the time of maximum eclipse, the eclipse will appear total because more than 93 percent of the moon will be inside the umbra.

4.  Earth's shadow cone is approximately ________________ miles long.
d. 840,000
As the moon's greatest distance from Earth rarely exceeds 260,000 miles, lunar eclipses will continue through the rest of Earth's history, until, of course, the Sun perishes.  Even though the moon is slowly receding from Earth, it will never venture far enough away to ever be beyond Earth's shadow cone.

5.  The moon's orbit intersects Earth's at the ____________ node and the ______________ node.
a.  ascending; descending  
The moon reaches the ascending node just prior to moving north of the ecliptic. The moon passses through the descending node just before it moves south of the ecliptic. 

6.  The umbral magnitude of a lunar eclipse inidcates____________.
b. the percentage of the moon's angular diameter that enters the umbra
The percentage of the moon's face that enters the umbra is known as its obscuration. 

7. The first eclipse in Saros 180 will occur on August 28, 2827.  Which of the following statements pertaining to this Saros cycle is/are true?
a.   the first eclipse will be a partial penumbral
b.  only the lower part of the moon's limb will pass through the penumbra during the first eclipse.
c.  the lunar eclipses in this Saros cycle will occur around the ascending node
d.  the second eclipse in this Saros cycle will occur in early September in the year 2845.  
All the statements are true.

Explanations
a =>  the first eclipse in every Saros cycle will be a partial penumbral eclipse

b =>  this Saros cycle occurs around the ascending node.  Consequently, the first eclipse will bring the moon along an arc that crosses the upper part of the penumbra.

c => The Saros Cycles denoted with even numbers occur around the ascending node.

d => Successive eclipses within any given Saros Cycle occur 18 years and 11 days apart.  The second Saroc 180 eclipse will happen on September 7, 2845.

8.   What happened to the men who ate the Lotus fruit?
c. they stopped caring about everything in their lives and wanted only to eat more fruit
Odysseus had to drag the men back to the ship in order to make them leave the island of the Lotus eaters.

9. The amount of time separating successive full moons is called a _____________ month.
c. synodic
A synodic month is approximately equal to 29.5 days

10.  The last total lunar eclipse in the Saros 126 cycle occurred on ________________.
a. November 9, 2003
Totality only lasted 21 minutes and 58 seconds because the moon spent only a brief amount of time within the umbra.  


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