Wednesday, June 6, 2012

Transit of Venus: Once-In-A-Lifetime Astronomical Event?

Though it’s been cloudy for three days straight in my neck of the woods, does the June 6, 2012 transit of the planet Venus across the face of the Sun really the once-in-the-lifetime astronomical event it was touted to be?

By: Ringo Bones

I just caught the one back in 2004 using an improvised welder’s protective glass as an ad hoc filter for my trusty-but-rusty Celestron. And comparing one view via the “protected” naked eye observations, all I can say that the transit of Venus across the face of the Sun would seem rather “abstract” to the astronomically uninitiated; But why the fuss across the global astronomical community?

 First of all - transit is an astronomical term defined by the passage of a celestial body across a line or region in the sky. A star in transit when on the celestial meridian; the planets Mercury and Venus appear as dark spots when the transit across the disc or face of the Sun; a moon or a natural satellite is in transit when it crosses the disc of the primary planet such as Jupiter. Transits that are visible to the (protected if necessary) naked eye are extremely rare astronomical events.

The transit of Venus across the Sun’s disc only happens every 105 years, and they usually last about seven hours. The first recorded viewing of the phenomena was back in 1639 Jeremiah Horrocks and William Crabtree. Another reason why the astronomical community makes a big deal about it is that transits are a very reliable method of confirming the existence of planets orbiting in other star systems / solar systems. In other words, they are a very useful method in finding extra-solar planets tens or even hundreds of light-years away.

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