Venus Transit 2012
Open to the Public!
Some club members with telescopes and special solar filters will be getting together to view the Venus Transit on June 5, 2012. The public is invited to come and share this special event with us.
Location: Arvest Bank Parking Lot, 4225 SE Adams Road (just north of Walmart Supercenter)
When: Tuesday, June 5, 2012
Time: From 5:00 pm to sunset, which is a bit after 8:30 pm
Weather: Requires skies at least clear enough to view the sun. We will not set up if the skies are overcast.
A Rare Event. Venus transits are rare events, and this one will be the last in this century. Don’t miss it! Here are the event times for Bartlesville, OK:
Start Time: Ingress Sun, external, 5:05 pm, CDT
Start Time of Full Ingress: Ingress Sun, internal, 5:23 pm, CDT
Sunset Time: 8:39 pm
Venus starts across the sun from the outer edge on June 5 at 5:05 pm, local central daylight time in Bartlesville, OK. It will reach about half-way across the sun when the sun sets at 8:39 pm, CDT.
CAUTION. Potentially Hazardous. DO NOT LOOK directly at the sun without proper protection. Direct viewing without using the proper equipment can lead to permanent damage to the eyes, and you will not notice it until a few hours later. Simply darkening the sunlight is not sufficient. While the sun’s glare may be dimmed with such devices as sunglasses, invisible radiation may get through and still damage your eyes. Here are some items often tried that are NOT safe for directly viewing the sun: sunglasses (even if stacked), smoked glass, crossed polarizing filters, neutral-density camera filters, metalized candy wrappers, and compact discs.
DO USE the proper equipment for viewing this solar event. Specialized solar filters (simple ones that fit over the eyes can be obtained very inexpensively or for free) are the best choice. Welder’s filters (shades 13 or 14) may also be used. Welder’s filters with shades lower than 12 are not recommended. Other methods of viewing the Venus transit event include indirect projection methods (some are very simple to make yourself), and internet live webcasts, such as http://sunearthday.nasa.gov/2012/transit/webcast.php from Hawaii.
What is a Venus Transit, anyway? A Venus Transit is rare predictable event (this will be the last one in this century and our lifetime!) where Venus passes directly between the Earth and the Sun, becoming visible against (and hence obscuring a small portion of) the solar disk. Because of the relative distances between the Earth, Venus, and the Sun, it will appear as a small black dot against the bright disk of the sun. Because the orbits of the Earth and Venus are different, perfect alignments are rare. Unlike Venus, the moon is much closer to the Earth and the orbits intersect more frequently. When the moon passes directly between the Earth and the Sun, a much larger shadow is cast on the Earth and we have a solar eclipse.
Historical Importance. Since the invention of telescopes in 1610, there have been only 7 occasions to observe a Venus Transit. This one will be the 8th and the next one won’t be until December 11, 2117! There are many articles on the internet that talk about astronomers using this event to do research. For example, on December 4, 1639, the Venus Transit was used to measure the apparent diameter of Venus. In 1761 and later, Venus transits were used to estimate the distances between the Earth, Venus and the Sun. Relative distances of the planets in our solar system were known at that time, but actual distances were not. Because Venus is so bright, direct measurements are inherently inaccurate. Unfortunately, other quirks not known previously about Venus transits introduced complications, and ultimately after many years, other methods were used instead. While these parameters our now accurately measured by other means, this event does offer an opportunity to conduct meaningful research. Studies are planned to help calibrate our methods being applied in another active area of astronomy, exoplanet exploration. We are currently using these same events to identify and characterize planets in other solar systems, and using Venus and our Sun as a standard where more information is known, we can better understand our distant neighbors in our galaxy.
Online Resources. There are many resources available to learn more about Venus transits. Here are a couple of them on the internet.
Sky & Telescope:
https://skyandtelescope.org/astronomy-news/observing-news/2012-venus-transit-streports/