THE SOUTHWORTH PLANETARIUM
70 Falmouth Street      Portland, Maine 04103
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43.6667° N    70.2667° W  Founded January 1970
2022-2023: LXV
Sunrise: 6:15 a.m.
Sunset: 5:32 p.m.
Civil twilight begins: 5:46 a.m.
Civil twilight ends: 6:01 p.m.
Sun's host constellation: Aquarius
Moon phase: Waxing gibbous (87% illuminated)
Moonrise: 1:32 p.m.
Moonset: 5:21 a.m. (03/04/23)
Julian date: 2460007.29
"If the dinosaurs went extinct 65 million years ago, then why is Earth only
2021 years old?"
- 'Questions that people have actually posted.'

THE DAILY ASTRONOMER
Friday, March 3, 2023
Quiz # 15: The Jovians

And, yes, the quiz has returned, as well. Now that we've all been watching
Jupiter and Venus dancing in the east, what better time to offer a quiz
about Jovian, or 'Jupiter-like' planets?


[image: pluto-gas.jpg]
*1. True or false:   Jupiter is more massive than all the planets put
together?*

*2. Which of the gas giants has the greatest number of known moons?*
a.  Jupiter
b.  Saturn
c.  Uranus
d.  Neptune

*3.  Which of the gas giant planets contains a "Great Red Spot?"*
a.  Jupiter
b.  Saturn
c.  Uranus
d.  Neptune

*4.  Which gas giant planet is rotating "on its side?"*
a.  Jupiter
b.  Saturn
c.  Uranus
d.  Neptune

*5.  Which of the gas giant planets require more than 100 Earth years to
complete a revolution around the Sun?  (Could be more than one.)*
a.  Jupiter
b.  Saturn
c.  Uranus
d.  Neptune

*6.   Which of the gas giants did Voyager 2 encounter during its mission?*
*(Could be more than one)*
a. Jupiter
b. Saturn
c. Uranus
d. Neptune

*7.  When was Uranus discovered?*
a.  it has been known since antiquity
b.  1678
c.  1718
d.  1781

*8.  When was Neptune discovered?*
a.  it has been known since antiquity
b.  1781
c.  1846
d.  1930

*9.  Which of the following gas giant planets have rings?  (Could be more
than one)*
a. Jupiter
b. Saturn
c. Uranus
d. Neptune

*10.   Which of the gas giants planets are named after Greek mythological
figures?*
a. Jupiter
b. Saturn
c. Uranus
d. Neptune
e.  none of the above


ANSWERS

1.  False!
If you put all the planets together, you have to include Jupiter!

2.  b.  Saturn
Note that we wrote "known moons," as opposed to "moons," as we have no idea
how many moons revolve around these distant worlds.  We only know how many
have already been found.

Saturn has 82 moons!
Jupiter is a close second with 79 known moons
Uranus: 27
Neptune:  14

We've asked this question before and posted different answers.   If we post
this question next year, the answer might well change again.

3. a.  Jupiter
The "Great Red Spot" is a massive storm more than twice Earth's size.
 This monstrous maelstrom has been raging possibly for centuries.   While
it has been constantly observed since 1830,  Giovanni Cassini recorded a
spot in the mid 17th century: possibly the same storm we can see today.

4.  c.  Uranus
Uranus is nearly rotating on its side and keeps one pole toward the Sun.
 Uranus most likely sustained a devastating impact early in its life.
 Consequently, the planet was almost knocked over relative to the plane of
revolution.

5. d. Neptune

The farther a planet is from the Sun, the greater the duration of its
orbital period.   The three inner gas giant planets require less than a
century to complete an orbit around the Sun.

Jupiter  11.82 Earth years
Saturn  29.46  Earth years
Uranus  84.01 Earth years
Neptune  164.79 Earth years

6. a. Jupiter
b. Saturn
c. Uranus
d. Neptune

Yes, Voyager 2 encountered them all in the following years

Jupiter      1979
Saturn       1981
Uranus     1986
Neptune   1989

7.  d.  1781
William Herschel discovered Uranus even though he wasn't looking for a
planet.

8.    c.  1846
Two astronomers, Urbainn Leverrier (French) and John Couch Adams (British),
discovered Neptune by studying the perturbations in Uranus which they knew
had to have been induced by a hitherto unknown planet.

9.
a. Jupiter
b. Saturn
c. Uranus
d. Neptune
Saturn is not the only planet to have rings.   Granted, its ring system is
more extensive and far more magnificent than the rings of the other
worlds.     Voyager 2 imaged Jupiter's rings in 1979;    astronomers  James
Elliot, Jessica Mink and Edward Dunham discovered Uranus' ring in 1977.
Voyager 2 imaged Neptune's rings in 1989.

10.   e.  none of the above.
They are all named for Roman mythological figures



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