Eclipse Today

[mibn2cweus]

You are invited to post links, comments and questions on today's eclipse here.

http://www.space.com/19195-night-sky-planets-asteroids-webcasts.html

[murraymints]

Doubt anything is visible here.....

[lady-janine]

any time anything like this happens we can be sure of low grey cloud and rain. doubt if i will see anything through that lot byut thanks for letting us know..

[mibn2cweus]

It's a total miss for the UK.

Interactive map here - http://xjubier.free.fr/en/site_pages/solar_eclipses/HSE_2013_GoogleMapFull.html

[Jomlett]

http://www.bbc.co.uk/news/science-environment-24794141

[Peter Pedant]

erm what is a hybrid eclipse please

[jno]

total and annular both

[Old_Geezer]

I shall need to look up how that happens. Surely over the width of the Earth the relative sizes of moon and sun remain the same, I'm having difficulty picturing how, at max, it can be total one moment at one place and not total at another moment at another place.

[mibn2cweus]

As the Earth is roughly spherical greatest eclipse generally coincides with where the Moon's shadow crosses the local meridian. The ratio between Sun/Moon distance from the centre of the Earth can vary significantly throughout the duration of an eclipse so that in rare cases the eclipse begins/ends as an annular/total or vice versa, while in this particular hybrid eclipse I believe it was annular, at both ends . . . not that there's anything wrong with that!

[Hypognosis]

For a limited time only (the page changes by the day) try
http://spaceweather.com/

There's a photo taken from an aircraft with a neat story to it.

I struggled to understand :-

"The ratio between Sun/Moon distance from the centre of the Earth can vary significantly throughout the duration of an eclipse"

because I couldn't help but think this was talking about the orbital distance of the moon from earth and couldn't see that changing on such a short timescale.

However, by picturing an imaginary cone, representing the moon's shadow, being wiped across the surface of a globe, I think I get it. Annular at the sunrise and sunset extremities but the moon is bigger in the sky at the midpoint, because the shadow hits the surface one earth-radius closer to the moon than it does at the E and W horizons.

[mibn2cweus]

This one? - http://www.launchphotography.com/Total_Solar_Eclipse_2013.html

[mibn2cweus]

//I struggled to understand :-

"The ratio between Sun/Moon distance from the centre of the Earth can vary significantly throughout the duration of an eclipse"

because I couldn't help but think this was talking about the orbital distance of the moon from earth and couldn't see that changing on such a short timescale.//

The timescale I had in mind was the several hours from the onset of the eclipse (in this case the west Atlantic) until the eclipse ends (the east coast of Africa). In that time frame the relative distances between Earth, Moon, and Sun can change enough for an eclipse to begin as an annular and end as a total, or vise versa.

[mibn2cweus]

According to the "Five Millennium Catalog of Asymetric Hybrid Solar Eclipses" This was a 'Class 3' Hybrid eclipse beginning as an annular and ending as a total eclipse. Asymetric hybrid solar eclipses (Class 2 or 3) occur with a frequency (on average) of about once per century.
http://eclipse.gsfc.nasa.gov/SEcat5/SEhybrid5a.html

[Hypognosis]

Good spot, finding the original webpage those photos came from. Thanks.