Full Sun - Half Moon?

[Captain Colostomy]

This astronomy stuff is all over my head....

Lemme guess...plate tectonics are beneath you?

(Boo, hiss...by the way).

[Chas]

This astronomy stuff is all over my head....

Lemme guess...plate tectonics are beneath you?

(Boo, hiss...by the way).

And when it comes to marine biology, I'm all at sea.

As for spelunking, I'm in the dark.

[Cyberman]

It appears that way because the moon is at a ~90 degree angle with respect to the earth-sun orientation.

Took a while to work this out in my head, but I got it. Thanks!

Just to make your head spin a bit more, the half-Moon phase that you saw is called 'last quarter'.

[Captain Colostomy]

Lemme guess...plate tectonics are beneath you?

(Boo, hiss...by the way).

And when it comes to marine biology, I'm all at sea.

As for spelunking, I'm in the dark.

*Shakes head*

Nerd humor...

[Cyberman]

Thermodynamics leaves me cold, I'm at sixes and sevens with mathematics and I just don't dig archaeology.

[pocaracas]

And you want to know something awesome?!

If the angle between the sun and moon is ~180º, you get a full moon!
If you get exactly 180º, you get a lunar eclipse!

If it's ~0º, you get a new moon.
If it's exactly 0º, you get a solar eclipse!

And that's why people study astronomy...

Well... Eclipses require things to be lined up along the plane of the earth's orbit, you can have a 0/180 degree alignment along the lunar orbital plan and not have things line up correctly. That's why, even though 0/180 alignments occur every lunar orbit, eclipses are less frequent.

Interesting eclipse factoid: Solar eclipses are more common than lunar eclipses. However, as the shadow path is much smaller in area for solar eclipses, a particular location will have a viewable lunar eclipse much, much more frequently (i.e. solar eclipses are viewable only from a typically narrow path on earth, whereas lunar eclipses can be viewed from any location where the moon is visible).

hehe, hence my distinction between ~180 and exactly 180.
~180 is when the two planes don't align... exactly 180 is when they align and you get an exact 180º, using the Earth as the center.

[Ben Davis]

Thermodynamics leaves me cold, I'm at sixes and sevens with mathematics and I just don't dig archaeology.

Psychology isn't all it's cracked up to be.

[Cyberman]

Well... Eclipses require things to be lined up along the plane of the earth's orbit, you can have a 0/180 degree alignment along the lunar orbital plan and not have things line up correctly. That's why, even though 0/180 alignments occur every lunar orbit, eclipses are less frequent.

hehe, hence my distinction between ~180 and exactly 180.
~180 is when the two planes don't align... exactly 180 is when they align and you get an exact 180º, using the Earth as the center.

Not quite, as CD correctly pointed out. Your model confuses the Earth-Moon plane with the Sol-Earth plane. We still get the whole 180 thing with the E-M plane even when the S-E one doesn't align with it. It's a bit like me, standing at our fourth-floor window, watching two cats in the street circling each other (or if it's a Friday night, two lasses in tube tops and belt skirts circling and hissing about someone called Gary). From here, I can see the two of them no matter where each of them are in their orbit of each other. If I went downstairs and got to their eye-level, they would eclipse each other every time they reached the 180 points relative to my eyeline.

Here's one to shit up the theists though: another word for one body (planet, moon etc) eclipsing another is 'occultation'.

[pocaracas]

I'm not using either plane.... I'm using the triangle formed by the sun, earth and moon.

[Cyberman]

I realise, but that triangle is only planar at certain very specific times. When it's not, no eclipse.