Lunar Eclipse

Originally posted by Nordlys
The eclipse glasses I had for the solar eclipse in 1999 had a warning that you should move carefully while wearing them. Really helpful, how else would I have noticed that I couldn't see anything else than the sun through them?

I have viewed (and photographed) the uneclipsed sun through a telescope. Pretty cool. But I fitted the telescope with a proper sun filter. 🙂

The Health and Safety Executive states that even telescope sun filters are unsafe. If they crack then you can be in a bit of trouble.

Originally posted by yo its me
Oh! I thought they happened more often. I saw the soloar eclipse and I rememebr that being not so frequent. Well I still have a chance to see it for myself then, that's good 🙂

Total solars are rather more frequent around the equator, for tolerably obvious reasons. They're rare up here in Europe or the USA.

Richard

Originally posted by Shallow Blue
Total solars are rather more frequent around the equator, for tolerably obvious reasons. They're rare up here in Europe or the USA.

Richard

What's obvious to you is not so easlily obvious to me!!

Merry Christmas Shallow Blue 🙂

Originally posted by yo its me
What's obvious to you is not so easlily obvious to me!!

Merry Christmas Shallow Blue 🙂

I agree it isn't obvious for someone who has never looked at astrophysics in any depth. A very brief lesson:

As I am sure you are aware, the Earth is tilted on his axis relative to its orbit around the sun (approx 23.5 degrees from its orbital plane). This is the cause of the seasons. Colder in the north when the north is tilted away from the sun, and hotter in the north when tilted towards the sun. For the south, the opposite is true. Anywhere where the the sun can potentially be directly overhead is the tropical zone. This means that the tropic of cancer will be 23.5 degrees north of the equator and tropic of capricorn to the south (boundaries of the tropical zone).

As for the moon going around the Earth, the orbital plane relative to the Earth's orbital plane (the inclination) is offset by 5.145 degrees.

Because of the relatively close proximity of these planes to the equator, it is statistically more likely that solar eclipses will be visible nearer the equator. Lunar eclipses are just a big shadow on the moon, so they will be visible where ever the moon is visible at the time (i.e. night time).

If the Earth wasn't tilted and the moon's inclination was in plane with the Earth's equator, you will get solar and lunar eclipses every month. Solar eclipses will then only ever be visible over the equator (and a very narrow width either side).

As it stands now though, because of these planes being offset. Most months the shadows of the moon over the Earth (solar eclipse) and the shadows of the Earth over the moon (lunar eclipse) miss each other.

Originally posted by lausey
I agree it isn't obvious for someone who has never looked at astrophysics in any depth. A very brief lesson:

As I am sure you are aware, the Earth is tilted on his axis relative to its orbit around the sun (approx 23.5 degrees from its orbital plane). This is the cause of the seasons. Colder in the north when the north is tilted away from the sun, and hott ...[text shortened]... (solar eclipse) and the shadows of the Earth over the moon (lunar eclipse) miss each other.

Thank you Lausey. It's nice to learn something new 🙂

Originally posted by Very Rusty
Send out PM's, see how the Vote goes. 😉

Nah. Might be construed as spam.

Originally posted by yo its me
Thank you Lausey. It's nice to learn something new 🙂

I am on a roll now. As I have a keen interest in astronomy, here are some more interesting facts about eclipses.

A total lunar eclipse often has a reddish glow because of the Earth's atmophere. The brightness of this glow depends on the atmospheric conditions. The Earth doesn't completely block out the sun's light because the atmosphere refracts (bends) the light, the same way light refracts in a glass of water. The orange glow is because most of the blue light in the visible region of the electromagnetic spectrum has been absorbed (due to Rayleigh scattering) and you are left with mostly the red end of the spectrum. Same principle as an orange sunset.

Most of the world when viewing a solar eclipse will only see a partial one, but even places where the moon goes in front of the sun dead centre, it still isn't necessarily a total eclipse. There are situations where you have an annular eclipse (that is spelt correctly and doesn't mean it happens yearly). This is when the moon is visibly smaller than the sun (the moon is considerably physically smaller than the sun, I am talking visibly from Earth) and you see a black disk of the moon with a "ring" of the sun around it. This is when the moon is furthest in its orbit (apogee) from the Earth and the Earth is closest in its orbit (perihelion) to the sun. For a total solar eclipse, the opposite has to occur (perigee and aphelion).

Originally posted by lausey
I am on a roll now. As I have a keen interest in astronomy, here are some more interesting facts about eclipses.

A total lunar eclipse often has a reddish glow because of the Earth's atmophere. The brightness of this glow depends on the atmospheric conditions. The Earth doesn't completely block out the sun's light because the atmosphere refracts (bends) th ...[text shortened]... to the sun. For a total solar eclipse, the opposite has to occur (perigee and aphelion).

Fascinating. I was thinking of taking an evening course (self interest) and this has brought to mind a question that has been haunting me for decades. This may just be the answer to that quest. "When the moon is in the seventh house and Jupiter aligns with Mars...."