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2004 Venus Transit In Pictures

oneiros27 writes "For those astronomy fans out there -- pictures are starting to come in from the 2004 Venus Transit (where Venus passes in front of the sun). Times of the transit will vary by city, but make sure you use safe techniques for viewing the sun if you want to look for yourself." Anonymous Coward writes "Check out the transit of Venus webcast from Australia. It starts at 4.50 UTC on June 8." Update: 06/07 04:03 GMT by T : Linked webcast link updated to a URL projected to better handle the load, thanks to reader Tom Minchin.

74 of 214 comments (clear)

  1. Unfortunately... by Anonymous Coward · · Score: 3, Informative

    Golden State (California) wouldn't be able to see it.

    1. Re:Unfortunately... by NIK282000 · · Score: 5, Informative

      transists come in pairs with venus, there shoud be another one in a few years then it will be a long time till the next pair.

      --
      Dear aunt, let's set so double the killer delete select all
  2. Let the Bananarama jokes by foidulus · · Score: 2, Funny

    commence!

    1. Re:Let the Bananarama jokes by martinX · · Score: 4, Informative

      A band called Bananarama did a cover of a song called "Venus" in the eighties (1986). It was originally done by Shocking Blue* in 1970.

      Lyrics here.

      It is a bit of a stretch to go from from a story on a planetary event to a forgettable eighties band, but this is /.

      * That site also tells us that "Venus is the only song in the history of the Billboard charts to hit number one three times (first time on February 7, 1970, second time on June 20, 1981 by "Stars On 45"; third time on September 6, 1986 by Bananarama)." So there. Wow. And now I can't get the damn song out of my head... she's got it, yeah baby she's got it ...
      --
      When they came for the communists, I said "He's next door. Take him away. Goddam commies."
  3. OH DEAR GOD by Anonymous Coward · · Score: 5, Funny

    I'M BLIND!!!!

    I tried to look at Venus, and I burned out my eyes! Damn you Slashdot, damn you Sun! (The Sun, not Sun the Java people!)

    1. Re:OH DEAR GOD by pilot1 · · Score: 5, Funny

      He typed, of course.
      Any good geek can launch Firefox, navigate to Slashdot, find a story, and post a comment without looking at the screen.

    2. Re:OH DEAR GOD by Boglin · · Score: 4, Funny
      Any good geek can launch Firefox, navigate to Slashdot, find a story, and post a comment without looking at the screen.
      Except, being blind, he wouldn't be able to read the article before posting.... Wait a sec! Just how man blind people do we have here?
    3. Re:OH DEAR GOD by AsmCoder8088 · · Score: 2, Interesting

      You can actually look at the Venus-Sun transit through telescopes using a solar filter. I own an eight inch schmidt-cassegrain, and equipped with an appropriate eight inch filter, I would be able to see the transit much better than just regular gazers of the transit. Hypothetically, if you had a few grand lying around right now, you could buy a nice telescope and have a much better look at the transit.

    4. Re:OH DEAR GOD by theyre+watching+you · · Score: 3, Funny

      Just how man blind people do we have here?

      well, according to the uid's... about 780,000.

  4. Terraforming by Anonymous Coward · · Score: 4, Funny

    It would be interesting if someday human could live in Venus (w/ the little help from terraforming), and experience the transit directly from there.

    1. Re:Terraforming by Exiler · · Score: 5, Funny

      I think they'd call it "Night" or "DEAR GOD! THE GOOGLES! THEY DO NOTHING!"

      Lameness filter encountered. Post aborted!
      Reason: Don't use so many caps. It's like YELLING.

      --
      Banaaaana!
    2. Re:Terraforming by cynic10508 · · Score: 4, Funny

      Yeah, those Google people do seem to be stalling quite a bit on the IPO. But that's no reason to take the Lord's name in vain like that! Sheesh...

    3. Re:Terraforming by Anonymous Coward · · Score: 2, Informative

      > It would be interesting if someday human could live in Venus (w/ the little help from terraforming), and experience the transit directly from there.

      While in priciple those are interesting ideas, I see two potential obstacles:
      1) Even with terraforming, Venus' proximity to the Sun would make average surface temperatures too warm for comfort. Maybe even too warm for life. Shielded surface habitats or underground structures might be the only options.

      2) If you're on the planet and it's making a transit of the Sun, you can't see it. Think about it, at any given moment the Earth is making a similar transit, and somebody (something?) watching us from a certain point in the outer solar system would have a similar effect.

    4. Re:Terraforming by sentientbeing · · Score: 2, Funny


      that reminds me. I know a lot of the solar system has already been explored one way or an other by man- but it came to my attention that nobody has actually landed on the Sun yet...?

      Now I know youre all going to say 'duh. thats stupid its way too hot'

      true. but only if you go in the daytime

      --

      ------
      beware he who would deny you access to information, for in his mind he dreams himself your master
  5. They Linked to Pictures? by FlipmodePlaya · · Score: 4, Funny

    NASA.gov is in for the Slashdotting of its life!

  6. If it hasn't started yet... by Anonymous Coward · · Score: 2, Interesting

    how are "pictures starting to come in"?

    1. Re:If it hasn't started yet... by sploo22 · · Score: 5, Informative

      If you look at the NASA website, it's just entered the sun's corona (from Earth's perspective). It hasn't actually gone past the disc yet, but it's still visible to the SOHO telescope.

      --
      Karma: Segmentation fault (tried to dereference a null post)
    2. Re:If it hasn't started yet... by barakn · · Score: 2, Informative
      it's just entered the sun's corona (from Earth's perspective)

      SOHO is in a halo orbit around the L1 Lagrange point, and so is not on the Sun-Earth line. As such, Earth's perespective is not the same as SOHOs.

      --
      "I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show
  7. Re:Sir? by Man+in+Spandex · · Score: 5, Insightful

    When an event such at this occurs once in a lifetime, for the scientific enthusiasts or hobbyist, this is more than just a round disc blocking another shiny round disc.

    We will learn more about this planet and how the corona varies compared to an eclipse.

  8. Cover for UFO by Hao+Wu · · Score: 4, Funny
    It's not Venus, it's SWAMP GAS.

    This is a big desert, you could really get hurt out here. Now go away.... remember that you saw nothing.

    --
    I suggest you read Slashdot
  9. Australia? by Jeremy+Erwin · · Score: 5, Informative

    The Australians will only be able to view a partial transit. According to my New Scientist, Eurasia and Africa will be able to view the entire transit, Eastern North America, South America and Western Africa will find that Venus will already be in transit at Sunrise, and Australia, Japan, Alaska and Indonesia will find the transit interrupted by sunset. New Zealand, the Western US and southern Chile will be unable to view the transit.

  10. I can see ... by acceber · · Score: 3, Informative
    ...the first contact tomorrow at 3:07 PM here in Sydney. The second contact at 3:26 PM and then the sun will set just before 5 PM.

    Perfect timing, as I will be able to see it straight after school, not to mention two hours of pure interesting and enlightening entertainment for free.

    Beats TV any day.

  11. eye safety by Sinful_Shirts · · Score: 2, Interesting

    When I was in middle school my teachers told me it was safe to look at partial eclipses with a welders mask on, but I have heard otherwise. Does anyone know about this?

    1. Re:eye safety by jdhutchins · · Score: 5, Informative

      Yes, it is safe, if you're using #14 or darker glass.

  12. Projecting by NIK282000 · · Score: 5, Funny

    It says that you can project an image of the sun with binoculars, Im hoping that a telescope will work as well, if not, watch the news for "Wild fire obliterates southern ontario, /.er in questioning"

    --
    Dear aunt, let's set so double the killer delete select all
    1. Re:Projecting by Theresa1 · · Score: 2, Informative

      To make things a bit clearer - you align the telescope so that the shadow it casts is as small as possible. That way it will be pointing directly at the sun. It's best to have the paper screen in shadow, so stick a bit of cardboard over the telescope to stop the sun shining directly on the screen (cut a hole in it to stick the telescope threough)
      Never look through a telescope at the sun

      --
      This is a manual signature virus. Copy to your signiture file and help me spread.
    2. Re:Projecting by Avian+visitor · · Score: 2, Informative

      Be carefull if you are using a reflector-type telescope - one with the mirror (for example Newton reflector). These kind of telescopes should never be pointed towards the sun - whether you are looking through the eyepiece or only projecting a picture of the sun to a screen.

      Because the mirror focuses the light, the lenses in the eyepiece can get very hot and can deform or even shatter.

      Better stay with binoculars. You can even use two pieces of paper. One black with a tiny hole and another one white to use as a screen.

    3. Re:Projecting by Idarubicin · · Score: 2, Informative
      Be carefull if you are using a reflector-type telescope - one with the mirror (for example Newton reflector). These kind of telescopes should never be pointed towards the sun - whether you are looking through the eyepiece or only projecting a picture of the sun to a screen.

      This is true of any telescope that doesn't have a miniscule aperture. If you have a large refracting telescope, you also run the risk of cooking the optics in your objective if you point it at the sun.

      To directly examine the sun using a telescope, obtain an appropriate solar filter of the type that goes on the front of the telescope before all of the other optics. These can be purchased for telescopes of any size--including reflecting 'scopes. Google for 'solar filter' and 'telescope' and you should turn up any number of suppliers. Do not buy a filter that sits at or near the eyepiece, and don't trust any filter sold by a company that distributes such devices. These filters have an unfortunate habit of heating up on exposure to concentrated sunlight. When they melt through the focused sunlight can rapidly blind an observer.

      The parent poster is quite right--for amateur observing of the transit, binoculars projecting onto paper are more than adequate, as is the use of a regular old pinhole. I was in southern Ontario for the annular solar eclipse back in 1994(?). Gaps between the leaves of trees made thousands of effective pinholes--you could see hundreds of little crescents on the ground under trees as totality approached; it was a very cool effect. My watch at the time had a relatively small, flat face and I was even able to use it as an effective low-quality pinhole to project an image of the eclipse on a wall.

      --
      ~Idarubicin
  13. Re:Question... by Phurd+Phlegm · · Score: 4, Informative
    Why do they call it Transit of Venus? Shouldn't they call it Eclipse of Venus or something like that?
    Well, if Venus were larger it would be an eclipse of the sun. But, as another poster already noted, it isn't. Good thing, too, since it would have to be around a half million miles in diameter and would probably have already hurled us and Mercury into the Sun or out into interstellar space.

    At least we'd all get an article on Slashdot....

  14. Re:Sir? by Anonymous Coward · · Score: 4, Informative


    actually dear poster its a twice in a lifetime experience..

    the next transit is due in 2012
    (+1 wiseass..)

  15. Re:Sir? by Anonymous Coward · · Score: 2, Informative

    When you say once in a lifetime, you mean twice in a lifetime? Venus will transit the Sun again in 2012, approx 8 years from now.

  16. Eureka! by EvanED · · Score: 5, Funny

    From the article on safe viewing:
    "More recently, solar observers have used floppy disks and compact disks (both CDs and CD-ROMs) as protective filters by covering the central openings and looking through the disk media."

    My Dear Watson, I have discovered another use for AOL CDs! Grab the one from under that cup over there; we're going to watch Venus!

  17. Canadian SCISAT-1 Spectra by GraWil · · Score: 5, Informative

    It seems there is a Canadian atmospheric research satellite that will also be making measurements of Venus. They are using a infrared Fourier transform spectrometer and cameras with the hope of improving models for extra-solar transits (think finding ET).

  18. Safety, Remember Safety by Talking+Toaster · · Score: 5, Insightful

    I'M BLIND!!!!

    For one thing, it doesn't start for another day and an hour or so.

    (I'll admit that I panicked and rushed outside and took quick looks at the sun, before I came back and read the article and realized we still have about 25 hours until it even starts.

    For another thing, slashdot was kind enough to post a link to safety instructions in the headline.

    So, what are solar filters? How much do they cost and where can I get one if I want to drive across the country in a mad dash to catch it at sunrise in South Dakota or whatever?

    I've been wanting to check out that Wall Drugs that so many people have bumper stickers for for awhile anyway. Maybe they sell solar filters? But if I'm going to drive halfway across the country I want more then just a pinhole thingy.

    Who's up for a road trip?

    But if you forgot safety and go temporarily blind, at least you can turn your Chinatown apartment into one big computer and discover a way to predict the stock market.

    --
    Howdy Doodly Doo!
    Anybody want some Toast?
    1. Re:Safety, Remember Safety by Fizzl · · Score: 3, Informative

      In case you are in Finland (which I'm fairly sure the parent is not), you can get free safety equipment from Ursa to view the transit. Email them for further instructions.
      I think there is some Ursa personnel at Tähtitorninmäki ("The observatory hill"), handing out filters.

    2. Re:Safety, Remember Safety by jamoross · · Score: 2, Informative

      Okay, looks like the flatness of the mirror is
      more important than I thought at first. And I
      guess not everyone is likely to have optical
      grade mirrors lying around like I do.

      But the platter out of an old hard disk is very
      flat. If it has bright plated media, it'll work.

      Now where's that old 800MB Quantum drive gone...?

      - jam

    3. Re:Safety, Remember Safety by Theresa1 · · Score: 2, Interesting

      (Specifically, the edges of the mirror act as an aperture similar to the pinhole camera effect.)
      Or why not just make a pinhole camera! Just get two bits of card. Make a hole with a pin in one, point at the sun and project the image onto the other one. The bigger the hole, the brighter, but fuzzier the image. You can get fancy if you like, go into a darkens room, black out the window except for a pinhole and project the image onto the opposite wall. The image will be bigger because the distance is greater. You could also try sticking a lens behind the pinhole, but you don't have to bother.
      Have fun

      --
      This is a manual signature virus. Copy to your signiture file and help me spread.
  19. Crater Naming by Aardpig · · Score: 5, Interesting

    Back when the Magellan mission was mapping the surface of Venus, I had a planetary geology friend who was involved in assigning names to features. I managed to persuade him to name a crater after my girlfriend Marianne, as a birthday present to her. At the time I thought this gift was pretty cool; unlike star names, which are meaningless, this was an official designation, and furthermore Venus was the Planet O' Love.

    My mistake, however, was to forgetting that Venus is eternal, but love isn't. Every time I see Venus hanging in the evening sky, I realize I named that damn crater after the wrong woman. LOL!

    --
    Tubal-Cain smokes the white owl.
  20. Applaud NASA by Anonymous Coward · · Score: 2, Funny

    Their servers are keepin it up good. They were prepared for the huge amount of attention from the mars landings so they have some amazing infrastructure.

    Thank god they didn't link to one of the 150,000kb RAW TIFFs. Nightmare for your connection and theirs =)

  21. List of live viewing gatherings? by orthogonal · · Score: 4, Informative

    Ok, let's get a list of public viewings together.

    Here's a list of web casts.

    Anyone else have information on live viewings?

    Thanks.

  22. Poster must have a time machine... by Anonymous Coward · · Score: 2, Funny

    According to the post "- pictures are starting to come in". According to my calculations the transit doesn't start for 26 hours from now.

  23. Re:Sir? by InfiniteWisdom · · Score: 2, Funny

    I'm going to die in 2011, you insensitive clod!

  24. Re:Question... by Anonymous Coward · · Score: 2, Funny

    it would have to be around a half million miles in diameter.

    Nonsense. Have you seen the sun lately? It's about the size of a quarter, max.

  25. BBC Coverage by amembleton · · Score: 4, Informative

    The BBC and Open University have a nice section on this. Its worth looking at.
    You can calculate the distance of the earth from the sun.

    If you're in the UK, the BBC have some programs covering this on Tuesday. There's live coverage at 9.50AM on BBC1 and another program on at 12PM on BBC1. Theres a full hour program on BBC2 at 11.20PM. All presented by Adam Hart-Davis.

    1. Re:BBC Coverage by phlako66 · · Score: 2, Interesting

      There's also a nice site in New Zealand (even though we won't be able to see the Transit this time round) about the T of V and Cook's 'voyage of discovery' that took place partially funded by the Royal Society sending him to Tahiti to record the transit. http://transitofvenus.auckland.ac.nz/

  26. Astonishing Scientific Breakthrough!!!! by sakusha · · Score: 3, Funny
    ..pictures are starting to come in from the 2004 Venus Transit..

    The photographic record of a Venus transit is nothing surprising. What astonishes me is that photographs are coming in from an event that is going to happen 2 days in the future.
    1. Re:Astonishing Scientific Breakthrough!!!! by barakn · · Score: 2, Informative

      The transit from SOHOs point of view will merely be a transit across the solar corona. Since Venus is already visible in the Lasco C3 image, the transit of the corona has essentially already started.

      --
      "I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show
    2. Re:Astonishing Scientific Breakthrough!!!! by barakn · · Score: 2, Informative

      I teach physics and astronomy at a university, and I know how to read the image. In case you weren't paying attention, SOHO won't see a transit across the solar disk. It will, however, see a transit across the solar corona, which extends well beyond 5 solar radii (why do you think Lasco C3 has such a wide field of view?). A transit occurs when an object crosses in front of a larger object, not limited to the disk of a star, planet, or moon. Did you hear about the transit of Titan across the Crab Nebula as seen in x-rays? The Crab has no well-defined edge, and yet we still speak of it being transited. The solar corona can be transited, and it is right now.

      --
      "I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show
  27. The U.S.A. will get a much better look in 2012 by Talking+Toaster · · Score: 5, Informative

    Here is the map of the transit for 2004.
    And here is the map of the transit for 2012.

    So while I won't get to see it this year unless I hop in my car and drive east for about 20 hours without rest, I will get to see it in 2012, unless I'm in Chille or Argentina, or something.

    The further north you are, the better your chances of seeing it.
    If you're in Antarctica you won't see it at all.

    --
    Howdy Doodly Doo!
    Anybody want some Toast?
  28. Confusing apparent size with real size by frizzbit · · Score: 5, Informative
    A transit is a more precise term and it refers to any event where two objects appear close enough in the sky that their disks overlap.

    The term eclipse is reserved for those events where the front object is large enough to significantly cover the back one.

    During the transit Venus will only cover about 1/900th of the solar disk and as such this is not usually referred to as an eclipse.

    What matters are the apparent sizes of the two bodies not their actual sizes, for example, the Moon is nowhere near half a million miles in diameter but when it transits the face of the Sun the event is called an eclipse. This is because, from the surface of the Earth, the apparent sizes of the Moon and the Sun are very similar and the moon is capable of blocking out a large fraction of the solar disk, sometimes even cover it completely.

    Imagine you travelled to Venus during the transit - the disk of the planet would get larger and larger until around 1 million kms (630 thousand miles) from the planet it would be large enough to totally eclipse the Sun.

  29. Voice Controlled Software by aussie_a · · Score: 2, Funny

    He would have posted the comment sooner but he had a cold.

  30. Re: Bananarama jokes? OK you asked for it ... by Ralconte · · Score: 2, Funny

    Hey, I heard the Monkeys got arrested ... it appears they got drunk and tried to peel Bananarama. *shudder* '80's humor, I'm embarassed that I actually wrote this down. Mod me way down, if you value our civilization.

  31. Re:Question... by martinX · · Score: 2, Funny

    No, you see Venus would have to be bigger to cause an eclipse. At least the size of the moon, maybe a little bigger.

    But since it's only the size of a Transit Van, it's passage across the face of the sun will only be The Transit of Venus.

    --
    When they came for the communists, I said "He's next door. Take him away. Goddam commies."
  32. Re:Question... by mt+v2.7 · · Score: 2, Informative

    If you RTFA (I know, I'm new here) it says that venus will appear as 1/33 the width of the sun.

  33. Reply by Bombcar · · Score: 2, Funny

    Watson: "My dear Holmes, I've been using AOL CDs to watch Uranus for years!"

  34. Bah! by MachineShedFred · · Score: 2, Funny

    West coast gets hosed again!

    We never get to see end-of-the-world omens here on the left coast!

    --
    Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
  35. Re:Don't worry 'bout it by CyanDisaster · · Score: 4, Funny

    ...I'm tempted to make a Soviet Russia joke about them Slashdotting us...

    What, like how in Soviet Russia, Nasa slashdots you?

    Hope be with ye,
    Cyan

  36. Viewing Venus in Sydney by Sailor+Coruscant · · Score: 3, Informative

    There are a number of places in Sydney holding events for the transit. It seems that Sydney Observatory is booked out, though you can go along in the evening to watch various webcasts of the transit as it goes on in sunnier places.

    The event I'm involved with is the Macquarie University Observatory event, which is taking place on the vacant lot at the intersection of Culloden and Talavera Roads, North Ryde (out behind the uni, not at the observatory).

    For a gold coin donation you'll be able to look through a telescope at Venus, see the video display from one of our ccd cameras, observe the sun through a variety of projection methods and also with eclipse shades. So, it's good value, and all proceeds go to building a new observatory and planetarium (as opposed to the Feed the Starvind Astronomers Foundation, which I think is a more noble cause).

    We'll be there from 3pm, see here for more information.

  37. 8 years by G27+Radio · · Score: 2, Informative

    I was listening to Day to Day/Science Friday in the car the other day and I believe they said the next one is in 8 years.

  38. 1882 transit photographs by Anonymous Coward · · Score: 2, Informative

    The US Naval Observatory has 11 photographic plates from the last transit of venus in 1882. As well, there are photographs from the various expeditions it sent out to take measurements for the purpose of calculating the AU, the distance of earth from the sun. These can be found here. There's also more fun to be had.

  39. Transit at University of Maryland, College Park by TheSync · · Score: 2, Informative

    Web page for University of Maryland, College Park, venus transit

    "Witness the first Transit of Venus in 122 years
    Join the Department of Astronomy
    Tuesday, June 8
    from 5:30 - 7:30 AM
    5th Floor Balcony, Plant Sciences Building
    Park (free) on Level 3 in the Regent's Drive Parking Garage (entrance on Stadium Dr.).
    Walk across the bridge (near section 3-4) in the southwestern corner of the garage.
    Enter the building and take the elevator (you will be on the 2nd floor) to the 5th floor.
    Walk out onto the balcony.
    In case of cloudy weather, join us in the Computer and Space Science Building (on Stadium Drive), in the Computer Lab, Room 1220. We will view the transit using the computers."

  40. Re:Eureka! -- need 2 CD thicknesses, no lacquer by waterbear · · Score: 2, Informative

    ... solar observers have used floppy disks and compact disks (both CDs and CD-ROMs) as protective filters

    I have discovered another use for AOL CDs!


    Sorry to spoil your day, I just tried it and it's yet another thing that AOL disks are useless for :-)

    I just tried a glimpse with various CDs. I find that a single unlacquered CD thickness leaves too much brightness, but 2 CD thicknesses (silver/recorded sides towards the sun) might be ok. (Care now!! Don't blame me if it's too bright for you!)

    But another thing is, the CDs probably need to be unlacquered on the non-recorded side (or at least have a partly unlacquered patch to see through). The colored lacquers cause light-scatter and fuzziness of the object seen. (The latest AOL disk had a thick red layer on the non-recorded side, and this made a very fuzzy sight, which I think will be useless for finding a small dot only about 1/32 the diameter of the sun.)

    -wb-

  41. Re:Question... by 26199 · · Score: 2, Informative

    It's not an eclipse because the sun isn't blocked out completely. Whereas transit is perfectly sensible, since venus appears to move across the sun...

  42. 1882 Venus Transit Quote by Titanium+Angel · · Score: 5, Interesting

    Just thought this might be an interesting thing to share with you:

    "There will be no other [transit of Venus] till the twenty-first century of our era has dawned upon the earth, and the June flowers are blooming in 2004. What will be the state of science when the next transit season arrives God only knows." - William Harkness, USNO, 1882

  43. Bob the Angry Flower by troon · · Score: 2, Funny

    Don't follow Bob's example...

    --
    Ydco co ,df C erb-y go. a Ekrpat t.fxrapev
  44. Yuppers by SnappingTurtle · · Score: 2, Interesting

    One time I was writing a web bot and it went berserk and started downloading images from NASA as fast as it could... 10,000 in half an hour. I emailed an apology to the web master. He emailed back and said they hadn't even noticed, that that my hits constituted an insignificant fraction of their daily traffic.

    --
    I've found that my posts don't format quite right w/o a sig.
  45. Re:Eureka! -- need 2 CD thicknesses, no lacquer by aallan · · Score: 2, Informative

    I just tried a glimpse with various CDs. I find that a single unlacquered CD thickness leaves too much brightness, but 2 CD thicknesses (silver/recorded sides towards the sun) might be ok. (Care now!! Don't blame me if it's too bright for you!)

    Congratulations, it's possible you've just done a great deal of damage to your eye. While CD's are (mostly) opaque to visible wavelengths, they're totally transparent to the infra-red. CD's, floppy disks and other media are not safe solar filters.

    Do not use make shift filters for direct solar viewing, unless you know the transmission coefficients of the material.

    Al.
    --
    The Daily ACK - Eclectic posts by yet another hacker
  46. Why do we care? by goober · · Score: 3, Informative

    A dot on the sun? Big deal? YES! The transit of Venus was a very important event in the history of astronomy and science. Previous transits were used by clever astronomers to calculate one of the most important measurements in all of science: the Earth-Sun distance, or 1 AU. By observing the transit of Venus from two distant locations on Earth and comparing the measurements you can determine the parallax angle. With those angles and one side of the triangle measured, simple geometry gives you the Earth-Sun distance. Once you have that number you can do all kinds of fun things; like figure out the distances to the rest of the planets, or by using the Earth orbit diameter to calculate stellar parallax and the distances to nearby stars, and on and on from there. The Venus transit is a *very* significant event.

  47. More Information by crashnbur · · Score: 3, Informative

    The Transit of Venus is a phenomena witnessed very seldomly -- in fact, next Tuesday's transit will be the first witnessable from Earth since 1882. (Google News points to hundreds of stories.) The transit of a planet occurs when it passes between another and the sun, thus only transits of Mercury and Venus are possible from Earth. It will begin at 05:13 Universal Time, which is 9:13pm July 7 on the US West Coast (more info), and it will last several hours. NASA has a map that shows when and where it will be viewable (more maps here), some safety tips for properly viewing the sun, and a Sun-Earth Day 2004 web site with lots more, including where to find webcasts. This Transit of Venus FAQ should answer many of your questions, including why transits of Venus follow a regular pattern of recurrence at intervals of 8, 121.5, 8, and 105.5 years. FYI, The event won't be visible in North American sky until the sun rises, and by then it will be almost over. If you miss this one, you'll have one more chance at it on June 6, 2012, when the transit will be most visible the Pacific.

    (I submitted this to Slashdot several days ago; I was rejected.)

  48. SciAm by Paulrothrock · · Score: 2, Informative

    If you want more info, your library should have the May 2004 issue of Scientific American, which has an excellent article about previous transits. It's amazing to see how a single event provides a reference point for the passage of time and progress of society. Imagine what it will be like when the first of the pair of Venus transits comes in 2117. Maybe we'll be watching it from Mars as well...

    --
    I'm in the hole of the broadband donut.
  49. Re:Eureka! -- need 2 CD thicknesses, no lacquer by EvanED · · Score: 2, Informative

    Uh, can you provide a source for this? I'm more inclined to believe NASA than a random post on /., no offense...

    According to this, CDs and Floppy disks both make safe filters. Optically crummy filters, yeah. But safe. Maybe because the document is specifically taylored to eclipses where the amount of sunlight is less?

  50. Re:8 years (yup) by Thieron · · Score: 2, Informative

    Space.com has an article on it. The next time is in 2012. "The next transit is on June 6, 2012 and will be visible from northwestern North America, northern Asia, Japan, Korea, eastern China, Philippines, eastern Australia, and New Zealand, according to NASA. Portions of the 2012 event will be visible in parts of North America, Asia, the Middle East, Europe and Africa."

  51. So what ? this what by mge · · Score: 2

    from http://www.wa.gov.au/perthobs/Venus/venus.html

    Transits of Venus across the disk of the Sun are among the rarest of planetary alignments. During the interval from 2000 BCE to CE 4000, a total of 81 transits of Venus occur, that is, one every 74 years on average. However, they almost always occur in pairs (separated by 8 years) and so even a long-lived person may not get to witness a Venus transit in their lifetime. The next transit of Venus will occur in 2012. More than a century will elapse before the next pair of transits in 2117 and 2125, and the two previous transits occurred 1874 and 1882.

    It is only during early December and early June that transits of Venus are possible. This is the time when Venus's orbital nodes pass across the Sun. If Venus reaches inferior conjunction (Sun, Venus and Earth aligned) at this time, a transit will occur. Transits show a pattern of recurrence at intervals of 8, 121.5, 8 and 105.5 years. The planet Mercury can also transit the Sun, and it orbits the Sun more quickly than does Venus, so it undergoes transits much more frequently. There are about 13 or 14 transits of Mercury each century. However, the size of Venus is larger (about 3% the Sun's diameter) and is more easily observable, and its proximity to Earth makes the highly desirable effect of parallax more pronounced.

    Edmund Halley first realised that transits of Venus could be used to measure the Sun's distance, thereby establishing the absolute scale of the Solar System from Kepler's third law. This is also the first step in determining the size of the Universe. Halley realised that the careful timing of transits could be used to determine the distance of Earth from the Sun. The technique relied on observations made from widely separated sites across the Earth. The effect of parallax on the remote observers would allow them to derive the absolute distance scale of the Solar System. Venus transits were better suited to this goal than were those of Mercury because Venus is closer to Earth and consequently exhibits a larger parallax. Unfortunately, his method proved impractical since contact timings of the desired accuracy are impossible due to the effects of atmospheric seeing and diffraction. Nevertheless, the 1761 and 1769 expeditions to observe the transits of Venus gave astronomers their first sound value for the Sun's distance.

    Transits of Venus have a special connection for Australians because it was after observing the 1769 transit in Tahiti that Captain Cook arrived on the East Coast of Australia and claimed it for Britain, thus setting in train its colonisation by Europeans.

    In the 18th century, the Pacific Ocean was still virtually uncharted and there were rumours of a large southern continent called Terra Australis Nondum Cognita (the southern land not yet known). French, Dutch and English sailors, had hunted in vain for this mythical land. The British Admiralty wanted to organise a scientific expedition to observe the transit of Venus due in June 1769 and the expedition was also given the secret mission of finding the southern continent.

    After observing the transit in Tahiti, Cook sailed on to the North Island of New Zealand and then the South Island. He found that neither island was joined to a large southern continent. He continued towards Tasmania and then northward, arriving at Botany Bay in April 1770.

    Radar measurements currently provide very accurate distances to the Sun and planets, so transits are now of less scientific importance. However, these rare and remarkable events remind us of a technique important to the development of modern astronomy.

  52. Pictures of Venus transit from Casablanca, Morocco by scitek · · Score: 2, Interesting

    Taken around 5:40 AM GMT, Sunrise - http://www.actane.com/perso/jvincent