One Week Left!

.....There is just one week left until the transit of Venus across the Sun.  I will very shortly have more specific information for a variety of places across the world, but if you wish to order special equipment for viewing the transit, you should probably do that as quickly as possible!

Safely Observing the Sun (Partial Eclipse Tomorrow)

.....On the afternoon of Sunday, May 20th (which would, I think, be Monday, May 21st in Japan), there will be an annular eclipse of the Sun.  I have not brought this up before because for most of the United States, the Sun will be very low in the sky, if not set.  The Western US might have a shot at it -- Denver will set the eclipse start with the Sun a whopping 15 degrees above the horizon -- and much of Japan will get to see the eclipse at its best.  In any event, I'll mention this here because it is good practice for looking at the Sun, practice that will come in handy at the Transit of Venus next month.

Timing on the Eclipse:
.....For the eastern US, the eclipse will start with the Sun set, or very close to the horizon.  .....From southeast Minnesota, the eclipse starts a mere eight degrees above the horizon at 7:36 PM, and progresses through sunset.

.....From Denver, Colorado, the eclipse starts at 6:41 Pm, and peaks at about 7:20 when the Sun is close (about 8 degrees above the horizon) to setting.  But hey!  It counts as an annular eclipse!  (If you recall all of the big fuss about the "SuperMoon" last month, when the full moon came about when the Moon was at the closest point in its orbit, now, this new moon, is when the Moon is about as far away as it gets, and therefore smaller against the sky, and therefore it cannot fully block out the Sun.

.....If you live in Japan, this will be an annular eclipse peaking around 8:30 in the morning.  You're set.

How To Look At The Sun:


....Most times, the information that you get is simply "Don't look directly at the Sun!" (or, the slightly longer "Don't look directly at the Sun, moron!".  If one does give advice, if the advice is imperfect, or misunderstood, then the people come to you for an explanation.  Well, I'm going to be precise and also tell you at the beginning that if you are going to blame the internet for bad things that happened to you, you are probably already in contact with half a dozen Nigerian Princes, and have enough problems.

Shiny

.....The danger in looking at the Sun is not in the "shiny", but in the type of shiny.  We can treat light as lots of little tiny particles of energy.  Each type of light has a different level of energy; particles ("photons") of red light have less energy per particle than particles of blue light.  The bluer the light, the more energy each particle/photon has, and light that is off the visible charts on the blue end (ultraviolet light, then X-rays, then gamma rays) has more and more energy per photon as you move off the blue end.  The types of light that a glowing object gives off depends on the temperature.  While a hot object gives off all types of light, the hotter the objects the more high-energy photons are part of that deal.  These higher energy photons are dangerous because any given atom or molecule in your body can only interact with *one* of these photons at a time, and the higher the energy of that one, singular, photon, then more likely that might smash up some part of cell doing really important things -- like in your eye, processing light.  A tremendous number of red photons is far less frightening than one UV photon.


.....The Sun is hot.  Really freaking hot.  Even with that, the dangerous (UV) light isn't coming from that part of the Sun.

Not shiny

.....Surrounding the Sun is an atmosphere of much thinner gases.  For reasons that still aren't completely understood, but probably have to do with the Sun's powerful magnetic field, the thin gas above the Sun is at a much, much higher temperature than the surface, so it is this thin gas giving off most of the UV light.  This part of the Sun does give off nearly as much light compared to the surface of the Sun, so the brightness of the Sun causes your eye's iris to shrink down, therefore being smarter than you apparently are -- but much less so during an eclipse.

not pictured: angels

.....Now on to how to not destroy your eyes just to see something cool.  (Although, to be fair, really, REALLY cool.)  You can find plenty of web broadcasts showing the eclipse, transit, whatever, but I'm going to assume that your are at least at little like me, since I'm the only person here while I'm writing this, and assume that part of the appeal is seeing the actual light coming from the Sun at the time that it is happening.  The first, and one of the safest ways of watching an eclipse/transit is by using a pinhole camera.  Take a pin, and punch a hole in a piece of cardboard/stiff paper, and then position another piece of paper beyond the hole.

.....The hole will cause an image of the Sun to appear on the other paper.  This is totally safe, and it will show the progress of an eclipse/transit very well, but details like sunspots will be hard to see.




 .....Shown below is an image of Sun as projected.

Can you see these on the left?

 .....Another thing that can be done is too use binoculars in much the same way.  You may need to use sunglasses due to the brightness of the image, but this is entirely safe to look at.










.....Speaking of sunglasses, do not simply toss on sunglasses and look at the Sun!!! (See: three exclamation points.  On the internet, this means that this is true.)  There do exist products that are safe for looking at the Sun, but they absolutely, positively have to be specifically made for looking at the Sun, and they have to stand behind this.  Simply using dark glass tricks your eye into opening the iris as widely as possible, but it does not protect you against ultraviolet light.  Pictured are some glasses that I found useful; I include them as an example without any particular endorsement.  they have worked well for me, although I get no money if they sell any.  (Although, hey guys, this space for rent!) 

.....I recommend using headwear to protect yourself from the Sun.  Choose something that typically does not get the bright sunlight of success to keep heat off of you.  I'm going with a Brewers cap here for that purpose.  Good luck!  Over the next three weeks, I'll have more and more about the transit.





(All photos not hyperlinked to public domain images are taken by the author, with the last image taken by Anne Marie Leckenby.

A Cool Link to a Past Transit of Venus

.....While I will soon post on how to look safely at the Sun (A tricky proposition, not to be undertaken flippantly), I ran across this excellent historical piece on the transit of 1769, and the scientific value we have gained from observing transits.

.....James Cook and the Transit of Venus

The Upcoming Transit of Venus

"Venus in the west was as bright as a street lamp, as bright as life, as bright as Miss Huntress' eyes, as bright as a bottle of Scotch"*

.....For months, now, Venus has been bright in the western sky.  As I write this, I am looking out of our living room window at Venus, shining brightly in the west.  (For the next couple of days, Venus will be near the star El Nath, in Taurus, the tip of the southern horn of the bull and very close to the Crab Nebula.)  Venus is now getting less and less prominent in the evening, getting closer and closer to the western horizon as Venus races to pass us on our orbit.  Most times, that would be that for seeing Venus, until Venus appears in the morning sky in late June.  This time, as Venus passes by us, it will be visible as a shadow across the Sun.

.....It would seem like this should happen more often; if you ask a small child to draw the solar system (I would do this all the time, so I assume that all kids do this), the final result of nearly circles in a flat page would be very close to how the solar system is - but not quite.  The flat sheet of paper is close, as the planets orbit in very close to the same plane.  the orbit of Venus, for example, is at an angle of 3.39 degrees to the plane of the Earth's orbit.  Now, if I said that I would fling a baseball not at the center of your face, but at an angle of 3.39 degrees above the center, you would probably not be very happy.**  However, at the distance of Venus at its closest, Venus makes a dot of only 0.008 degrees across against the sky, so the chance of this dot overlapping the half-degree dot of the Sun is very infrequent.  The last time, before 2004, was 1882.  The next time will be in December of 2117.

.....In the late afternoon of June 5th (next month!) we will get to see this.  The continental US will see Venus still transiting the Sun as it sets.  Japan would be an excellent place to view the transit from, with Wake Island being perhaps the best of all.  (Geez, this would have been a good time to go back to Guam.)  As this month progresses, I will have a number of posts on how to watch this, but I wanted to start now.

 .....Still, while I was trying to find a public domain image of Venus to use, I came across this image, where sunlight can be seen shining through Venus' atmosphere.  Cool.

.....My next post will be about how to view the transit safely.  One could buy special film glasses to view the eclipse, but be absolutely sure that the film is not just "dark", but is specifically made to protect against ultraviolet light.  My next post will talk about why this is a danger, but just for the love of anything you like actually looking at, never stare directly at the Sun unless you abso-fraggin'-lutely know what you're doing.

* Raymond Chandler ***, Trouble Is My Business

** Don't worry; this is just an example.  There is a fairly limited number of people that I would like to smash in face the face with baseball, so I use this for a purely illustrative purposes.  Still, if you're not sure, ask.

**duh