ECLIPSES Solar Eclipse Lunar Eclipse

Before we look at eclipses, let’s review where the Moon came from. The best theory is from an impact.

After the impact, much debris circled the Earth, as well as the new Moon (which you can see is still collecting more material from impacts).

The Moon ended up in an orbit that is not like rings around the Equator – it’s orbit changes angle.

Watch how its orbit changes – this is very important.

This is the side of the Moon we always see. What is happening with the Moon’s rotation and its orbit that causes us to see only this side?

That’s right! With a rotation time the same as its orbit time, this side would always face the Earth.

This is the “far side” we don’t ever see (but once probes and Apollo capsules orbited it, we finally got to see what was there). Why are there more craters on this side?

Solar Eclipse (Sun is “covered up”) Now that we know the positioning and behavior of the Moon compared to Earth, we can look at eclipses – and there are two types: Solar Eclipse (Sun is “covered up”) Lunar Eclipse (Moon is “covered up”) Solar Eclipse Lunar Eclipse

What is very interesting about solar eclipses is that the Moon is just the right size – and just the right distance, to almost perfectly cover the Sun! As the Moon moves away from Earth at a bit over 2.5cm (1 inch) per year, this “perfect” coverage will not happen in the future.

Here’s the Moon’s shadow passing over the Earth.                                                                             

Again, in color (at the top). Only satellites could give us this cool picture!

The Path of Totality is where the Sun is covered completely (in red). Other areas nearby will get partial coverage.

You have to be lucky to be in a solar eclipse’s Path of Totality. The next one for the U.S. (Oregon, so you’ll have to travel) isn’t until: 21 AUG 2017 between 11:00 – 11:30 a.m.. http://en.wikipedia.org/wiki/Solar_eclipse_of_August_21,_2017 https://www.youtube.com/watch?v=xBc8QHSsFgE

Solar Eclipses give us a wonderful chance to study the Sun – but DON’T look at them without proper protection. You will do permanent damage to your retinas!

You will do permanent damage to your retinas! Solar Eclipses give us a wonderful chance to study the Sun – but DON’T look at them without proper protection. You will do permanent damage to your retinas! get it…??

MOON PHASES

What’s happening in space (outer ring) Parallel rays from the Sun What we see (inner ring)

Since ½ of the Moon is always lit, “First Quarter” is not really correct (although that’s all we see). You may also see the phases named like this.

SOUTHERN HEMISPHERE PHASES and NAMES ARE REVERSED Watch carefully how light and shadow move from right to left – if you remember “ DOC ”, it’ll help you remember the proper order of the phases FOR THE NORTHERN HEMISPHERE. SOUTHERN HEMISPHERE PHASES and NAMES ARE REVERSED

Can you now name the phases? (click each time – start here and follow normal pattern – counter-clockwise) Can you now name the phases? New Moon Waxing Crescent Waning Crescent Third (Last) Quarter First Quarter Waxing Gibbous Waning Gibbous Full Moon

And finally – this is a very famous album cover, but there’s a small problem. No side of the Moon is always dark – but there is a “far side” we don’t get to see. Still… this is some really great music!!