Penumbral Lunar Eclipse Tonight

**thischarmingman** · 06/08/2009, 12:24 AM

n the early hours of Thursday morning, part of the Moon will pass through Earth's penumbra (the outer region of Earth's shadow). People on Earth will be able to see it as a slight darkening of the lower half of the Moon. This eclipse will be best observed between 1am and 2am, with the deepest part of the eclipse at 1:39am.

You'll really need a telescope though:

**First** · 06/08/2009, 3:10 PM

Originally Posted by thischarmingman

You'll really need a telescope though:

For those without a telescope TCM has provided cut out and keep. If you look carefully you will see Magicme putting out her pulling mattress

**Dodge** · 06/08/2009, 3:14 PM

When i read the title I thought it was one of those spambot thingies

**Mr A** · 06/08/2009, 3:18 PM

Worst.
Astronomical.
Phenomenon.
Ever.

**John83** · 06/08/2009, 3:43 PM

Originally Posted by Mr A

Worst.
Astronomical.
Phenomenon.
Ever.

You say that now, but what about the next extinction event bringing asteroid that hits the Earth? Where will you be then? And Bruce Willis? Where will he be? Huh?

The fact that the Earth casts a clear shadow which occasionally falls on the moon shows just how far away the sun is, and therefore how frigging huge it is (and if you think that's not a big deal, there was derision in Greece about 400BC when someone made the silly suggestion that the sun was at least as big as the lower third of Greece).

The fact that the moon enters it relatively rarely shows that it's a good distance away too.

With a full eclipse, you can see the curvature of the Earth projected on the moon, proving that we live on a spherical planet.

I think that makes lunar eclipses pretty cool.

The geometry in this is correct, but the distances involved make the shadow so much smaller that eclipses are rare. Anyway, it does make the notion of a penumbra clear.