(Originally posted on our 2012 Field Blog — by Chris Thawley)
While we specialize in Ecology here in the Langkilde Lab, inquiring minds always want to know; in this case, I was super-excited to see the transit of Venus this past Tuesday. In case you had somehow disappeared from the internet, a quick recap is in order: while Venus’ orbit does lie between the Earth and the Sun, it rarely passes directly between them because the orbits are at slightly different angles. Venus passing between the Earth and the Sun (called a transit of Venus) happens only twice every 113 years or so, making it the rarest type of solar eclipse in some books. Our last transit of Venus occurred 8 years ago, and the next won’t happen until 2117, meaning this is the last time for most of us to see it in our lives, barring some serious medical advances. The transit of Venus is also historically important, as 18th century astronomers used measurements taken by multiple observers around the world to more accurately calculate the Earth’s distance from the Sun (in what may have been the world’s first crowdsourced science project).
The transit was visible here in Andalusia from about 5 pm onwards, making for an approximately 3 hour long viewing window prior to sunset. Unfortunately, thunderstorms rolled in in the afternoon (as is their wont), and the western sky was full of clouds. After gazing at the sullen, grey sky for about an hour and with no change in the forecast on the horizon, I disappointedly took a shower to wash away my bitter tears. Howeever, at about 6:30, the clouds broke majestically and rays of sunlight shone right through the wet hair in my face as I was getting out of the shower. I threw some shorts on and ran outside to prep my viewing setup.
As staring at the Sun is generally inadvisable (unless you’re happy to go blind), an alternate viewing method is required. I chose to project the Sun’s image (a technique I learned in Camp Susque’s astronomy class). By taking the spotting scope we use for identifying lizards and aiming it straight at the Sun, I projected an image of the Sun onto some white paper (datasheets) that I had on a clipboard. I wasn’t sure how well this would work, but Venus was clearly visible along with some sunspots. Very neat!
If you missed it (and want to see some visuals better than mine), check out NASA’s videos at http://venustransit.nasa.gov/2012/multimedia/transit_videos.php?id=transit
Well, that’s all for astronomy until the Perseids in August!