Friday, March 18, 2011

Full Moon of 19 March 2011

Mark your calendar. On March 19th, a full Moon of rare size and beauty will rise in the east at sunset. It's a super "perigee moon"—the biggest in almost 20 years.

"The last full Moon so big and close to Earth occurred in March of 1993," says Geoff Chester of the US Naval Observatory in Washington DC. "I'd say it's worth a look."

Full Moons vary in size because of the oval shape of the Moon's orbit. It is an ellipse with one side (perigee) about 50,000 km closer to Earth than the other (apogee): diagram. Nearby perigee moons are about 14% bigger and 30% brighter than lesser moons that occur on the apogee side of the Moon's orbit.

Full report at:
Da Moon


hale-bopp said...

Thank you for not quoting a fear mongering article about this full Moon but rather one quoting my bud Geoff.

You probably will have a hard time telling the difference visually. There just aren't a lot of good things to compare the size of the full Moon to in the in the night sky. However, a simple photography project can reveal the difference.

Take out your digital camera and mount it on a tripod. Zoom in as far as you can and snap a picture of the full Moon (you might consider using the timer mode so you don't shake the camera when you push the button). Do the same thing next month using the same camera and zoom settings. Measure the diameter of the Moon in pixels in your photo editing program and you should be able to see the difference.

Sassa said...

When is sunset?

drewzepmeister said...

On the way to work this morning I saw the moon really close to the horizon. It kinda looked like a bigger than average harvest moon. It was sooo cool!

hale-bopp said...

I have heard several people call this a harvest Moon. The harvest Moon occurs in September. March is the Worm Moon.

The Moon illusion causes the Moon to appear larger near the horizon (even though it is really slightly larger when it is high in the sky since it is about 4000 miles, the radius of the Earth, closer to you at that time). There are several ways to deal with the Moon illusion.

First, hold the tip of your pinky just below the Moon when it rises and compare the size of the Moon the size of your pinky. Do the same thing later that night when the Moon is high in the sky.You will see the Moon is the same size (probably won't be able to tell it is larger without photographic equipment...the difference would be too small to see naked eye).

If you are impatient and don't want to wait several hours, there are a couple of ways to instantly destroy the Moon illusion. Get a used paper towel tube (or similar size tube) and look at the Moon through it. Eliminating the surrounding landscape from your field of view destroys the illusion. My favorite way is to bend over and look at the Moon between your legs (so you are looking at everything upside down) and the illusion goes away!

OrbsCorbs said...

I'm sorry, I can't help myself.

SER said...

Orbs...I do think you're loose'in it....LMAO

MinnesotaChick said...


Thanks for the giggle Orbs!

Why Not? said...

The girls and I were staring at the moon for awhile tonight.. like you said Hale it's hard to tell that it's much bigger, but man oh man is it bright.. beautiful

hale-bopp said...

It's pretty hazy here today. I might try to get a pic. The Moon could be a pretty deep orange when it rises if the dust doesn't clear by then.

kkdither said...

Just got back from the lakefront. There were cars lined up, lots of cameras on tripods. Very cool to see so many people out. The media has been doing a good job of promoting these events.

It was orange for a few seconds...hard to tell if it was really any larger. Once it finally made it all the way off the horizon, it ducked behind the clouds. Extremely short, but sweet. I tried to get a picture, but I'm pretty sure it failed.