Lecture 04: Moon Phases and Eclipses

[RJN]

The lecture video is embedded below but also available here in MP4 format.
Additionally, slides used in the lecture are embedded below but also are available here in Powerpoint format.
Questions after the lecture? Please ask them in here.

Click to play embedded YouTube video.

Wikipedia entries:

• Lunar phase
  Diurnal motion
  Celestial pole
  Solar Eclipse
  Lunar Eclipse

[Bill Nort]

You talked a moment about an astronaut seeing an earth eclipse while on the moon.
I think someone would have to spend two weeks on the moon for that to happen. I don't know so I'm writing you to see if you think this is true.
The rocket energy to reach the moon is least when the moon is leading or trailing the earth in our orbit about the sun at first or third quarter.
At these lunar phases we don't have to fight the sun's gravitational pull. Make sense?

[Scottyboybc]

I learned a little bit today. I also planned to see the partial lunar eclipse later this year. thanks for this series of lectures!

[Guthers]

You talked a moment about an astronaut seeing an earth eclipse while on the moon.
I think someone would have to spend two weeks on the moon for that to happen. I don't know so I'm writing you to see if you think this is true.
The rocket energy to reach the moon is least when the moon is leading or trailing the earth in our orbit about the sun at first or third quarter.
At these lunar phases we don't have to fight the sun's gravitational pull. Make sense?

I think you might have to wait up to a month for the Earth to eclipse the Sun, even if the nodes were lined up properly.

You may be right about having an easier ride to the Moon at half phase, but of course you have to return to Earth, so you would lose out on any help from the Sun's gravity on the way back. I expect the best way overall might be to go at new Moon and return at full.