2003 Transit of Mercury

angkor writes "It is happening today (all day in Asia)! NASA's SOHO page, Fred Espenak's 'Transit of Mercury' site, and live webcasts of the transit. You'll want to use the webcast, in spite of advice from our hometown paper, the Bangkok Post, which reported 'those interested in viewing it directly were advised to watch through black tinted glasses.'"

Comments

Already finished

[Angry Toad]

The transit is already over. Here is a direct link to the ESO site about it (with pictures). There's a Venus transit coming up next year, however, which is much rarer.

Re:Already finished

[KjetilK]

Yeah, I posted a note about this when the event started, but it is still pending.

Anyway, I was plugging our own webcast (from four cities in Norway, two of them had great weather), but that is all too late now...

Re:Already finished

[geekoid]

it might also be a novel idea if people who are interested in such phenomina would actually go to sites that specialize in these events and look at there calender.

I use the term loosly, but /. is a news site, and by definition, news has already happened.

Sunglasses

[FTL]

During one of the more recent solar eclipses in Canada, some teacher went out and bought 30 $1 sunglasses so that her class could watch the eclipse. Half of them ended up in hospital a few hours later.

It only takes a couple of stupid incidents like this to strike fear in parents and teachers everywhere. Now many schools close the blinds and go through what ammounts to a 'duck and cover' bomb drill whenever there's an eclipse.

Re:Sunglasses

[hubie]

Actually the teachers are correct. The sun is more dangerous during an eclipse because the sun is dark enough so as not to initiate our natural blink reflexes or aversion to bright lights; however, there is still significant blue to ultraviolet light being emitted from the corona. It is the exposure to this radiation that causes eye damage. A nice explanation can be found here.

Whether or not you are more likely to want to stare at an eclipse is irrelevant. It is the fact that you can comfortably stare at an eclipse long enough to cause retinal damage whereas you cannot easily do this otherwise with the sun.

Re:Sunglasses

[Nerant]

For those intending to use welder's glass for phototaking/viewing of such events, please get the proper grade of welder's glass, grade #14 and above is good enough.

Reference: -1-
-2-

Re:Sunglasses

[hubie]

It isn't just the UV that causes problems. It is the blue (and green) light as well (they don't necessarily burn tissue,they mess up the chemistry in the retinal cones).

To quote the aforementioned link:

Until 30 years ago, it was thought that the damage caused by the sun to eyes were the result of infrared (heat) injury to the retina alone. Then research on animals showed that ocular tissue rose in temperature by only a few degrees. We now believe that photochemical damage from visible blue light plays a major role in causing injury, especially when exposures are for more than a few seconds. If exposure is limited, some recovery of the nerve cells in the retina, is possible over a period of months.

Don't do it, kids!

[fobbman]

This is what your eyes will look like if you watch the event through dark tinted glasses.

Re:why not more often?

[sprouty76]

Yes, you answered your own question - it's because all of the planets orbits are at different inclinations, and therefore even when another planet is directly between earth and sun (or the sun is between the earth and planet) it isn't necesarily directly in between.

It's the same way that you don't get an eclipse during every full and new moon.

Don't forget the total lunar eclipse in a week!

[sanermind]

Don't forget about the total lunar eclipse coming in less than a week. [May 16]. Very romantic! Have fun.

Re:Rare Event?

[MartyC]

I would assume this is not the case. This means that this event only happens when the Earth and Mercury are approximately at the point of intersection of the two orbital planes at the correct time.

Correct. Mercury's orbit is inclined at 7 degrees to that of the earth. This makes the chances that mercury will cross the solar disk (roughly half a degree apparent diameter) at the exact moment rrequired for a transit pretty slim...

Open source software to simulate and make images

[alanh]

For those of you who are interested, Celestia is an Open Source application that can simulate the movements of the planets in 3d and generate some really cool pictures. It's available for Linux, Win32, and MacOSX.

One particularly good gallery is the Celestial Phenomina one by "Calculus." An example of a cool image is Saturn transit of the Sun as seen from Uranus in 2669.