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Spend the time outdoors
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Required Gear:

Smart phone


Transit of Venus App


On June 5 (USA), help measure the size of the solar system.
Use free app to record the times Venus transits the Sun!

On June 5, 2012 at sunset on the East Coast of North America and earlier for other parts of the U.S., the planet Venus will make its final trek across the face of the sun as seen from Earth until the year 2117. The last time this event occurred was on June 8, 2004 when it was watched by millions of people across the world. Get prepared for this once in a lifetime event! Check your viewing times/locations here: http://venustransit.nasa.gov/2012/transit/viewing_locations.php

For over 100 years the main quest of astronomers was to pin down the distance between Earth and Sun (the Astronomical Unit), which would give them a key to the size of the solar system. Careful studies of the transit of Venus became the gold mine they would harvest to reveal this measure. Editor's note: On 6/5, NASA will web cast the transit. Learn more here:http://venustransit.nasa.gov/2012/transit/

New technologies, like this VenusTransit phone app, will allow you to send observations of the 2012 Transit of Venus to a global experiment to measure the size of the solar system. The free phone app has been developed by Norbert Schmidt of DDQ in the Netherlands.

Prior to the transit, you can use the phone app to practice timing the interior contacts using a simulation of the transit. Additionally, you can see predicted times of contact for your location. During the transit, the phone app will assist you in measuring the time of the interior contacts. After the transit, you can access your data on a map on our website.

At the start and end of the transit, Venus will touch the limb of the sun on the inside. The exact times of these contacts vary according to your location on earth as a result of parallax. By combining the contact times measured all across the world, the distance to the sun can be determined. To download the free app, click on the "Join In" tab, above, or the "Get Starter" button on the right!




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