Pink Moon

Full Moon

Early in the morning on Wednesday, April 8, is the Full Moon (Supermoon!) for April, aka the "Pink Moon." No, the Moon does not exactly change colors like a chameleon, although that would be pretty cool. It appears big and pinkish due to its position in its elliptical orbit around Earth and the interaction of photons (teensy particles of light) with Earth's atmosphere.

Remember ROYGBIV from school daze? The visible light spectrum? Red, Orange, Yellow, Green, Blue, Indigo, Violet? Okay, okay, Pink isn't in the acronym, but neither is Iris or Aquamarine or a whole bunch of other colors in your Crayola box. Pink is a gradation of electromagnetic radiation at a slightly different frequency than ROY, G, or even BIV. It doesn't know that it's Pink. Somebody somewhere, maybe Mr. or Ms. Crayola, saw that frequency of light wave and pronounced it so. If you object, if you would rather call it "Mickey" or "Penelope" that's too bad, for alas, you are late to the crayon/photon party.

ROYGBIV

Visible light is just one form of electromagnetic radiation coming from the Sun, our star, which is basically a big ball of nuclear explosions converting Hydrogen to Helium and blasting wavelengths of energy every which way throughout the solar system in the process. Lucky for you, because without the Sun, you would never be able to watch all that Tiger stuff on TV.

Radio and TV waves are really, really long, like miles, whereas x-rays and gamma
 rays are super-short. Visible light waves are the only ones our eyes can see, hence the name. 

Okay, now that we are all experts in Physics, let's examine the central issue confronting us today. Whuffo is dat Moon pink, y'all? A picture is worth a thousand words. It also saves time, which I need to do because I have to go for a walk in the gorgeous UV light outside my window, pronto.

"But why does it appear to be bigger than usual, Mr. Wizard?" 

Well, the Moon's orbit is not a perfect circle. It is an ellipse, which means it looks like a slightly flattened circle. So sometimes the Moon is closer to Earth than at other times. When the Moon is the point of its orbit that is farthest from Earth, that position is called "apogee." When it is closest, it's called "perigee." Early in the morning on the 8th (depends on your time zone), the Moon will be at 90% perigee, in other words almost as close to Earth as it gets. And that's why this Full Moon will look bigger than it did last month.

Not to scale!!

We have taken to calling these perigee events "Supermoons" because we don't really have much else to do. You can only watch so much of that Tiger stuff on TV.

Anyway, go outside for a minute and look at it. It's purdy.

Peace, Love, and Apollo 13,

Jim