Tuesday, May 29, 2012

Watching Venus Fly Across the Sun

Photo Courtesy: Jan Herold
One of the best things about citizen science movement blogging is discovering the wide diversity of projects available to users.  Many have been created and each year more are added to the growing list of projects to join.  But today we talk about a special project.  A once-in-a-lifetime project.  A project tracking the upcoming Transit of Venus across the sun.

A similar event occurred eight years ago before the citizen science community was ready to participate.  The next one is scheduled for June 5-6, 2012, and there won't be another until 2117.  So this is literally our last-chance to get involved!

During a Transit the Sun, Earth, and Venus line up perfectly.  As Venus passes between Earth and the Sun, you can actually see it as a black dot traveling across the face of the Sun.  Kind of like an Eclipse but much smaller and with a planet.  Although fun to watch for the sheer  neatness factor, it has played a very important role historically in our understanding of the sky.  By positioning observers across the globe and precisely recording the time the Transit started and stopped, astronomers could calculate the distance between the Earth and the Sun.  It just took a little understanding of geometry (the principle of Parallax) and accurate data.

Obviously we already know the distance to the Sun and don't need a Venusian transit to calculate it.  However, there are still very important research being performed during this upcoming event.  Some scientists will be analyzing light passing through Venus' atmosphere to get a better idea of what the air is made of.  This helps not just for Venus, but as a "calibration run" for observing far-distant exoplanets as they cross in front of their own parent stars.  This helps us learn the limits of exoplanet observations and can provide clues for getting more information during future exoplanet transits.

So what are you waiting for?  June 5 is almost here!

Getting Started is Easy:
  • Learn more about the upcoming Transit of Venus and the history of transits at TransitofVenus.org, a web site published by Astronomers without Borders.
  • Download the VenusTransit mobile app for iPhone or Android.
  • Open the application and click on "Visibility".  It will find your current location and tell you when the Transit can be seen in your area.

  • Now you need to get ready for the event.  First, pick up some eclipse shades, welder's goggles, or other heavy-duty eye protection.  Staring at the sun literally causes blindness so you want to be prepared.  Pick some up at a local hobby shop, an astronomy web site, or even Amazon.com.
  • Practice making transit observations using the app's simulation function.  You will see a video clip of Venus from the 2004 event and must correctly log it's start/times.  Just press the timer when the planet first fully enters and first exits the sun's sphere.  After each attempt you will be given the "actual" observation so you can continue practicing your skills.

  • On Transit day, watch the sun (using proper protection!) and click on the app's "Timer" button.  Start and Stop the timer as the planet enters and exits.  The phone will do all the rest, although you can provide extra data or pictures once the Transit is over.

The Transit is fast approaching and there won't be another for 115 years.  So download the app now, pick up some glasses, and run a few simulations on your phone. And if you get any good pictures send them my way.  I'd love to see them!

FOR MORE MOBILE APPS VISIT THE NEW Citizen Science for your Phone PAGE !


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