This Wednesday people of the world may watch the venus transits depending on their location. The events are so rare that only six Venus transits have been observed since the invention of the telescope more than 400 years ago.
Transits happen when a planet crosses between Earth and the sun. Only Mercury and Venus, which are closer to the sun than Earth, can undergo this unusual alignment.
The last Venus transit was in 2004—above, the planet glides across the rising sun in a picture taken during the event from the North Carolina coastline. After 2012, we won't see another transit of Venus until 2117.
During the upcoming transit, Venus will look like a black dot gliding across the face of the sun over the course of about six hours.The entire transit of Venus will be visible from Hawaii, Alaska, New Zealand, Japan, the Philippines, most of Australia, and parts of eastern Asia. Countries in the Western Hemisphere will see the transit on Tuesday.
Observers in Europe, Africa, and western Australia, meanwhile, will see the sun rise Wednesday morning with Venus already on its face.
The 2012 transit of Venus will be visible even to the naked eye—although astronomers caution that people should never look directly at the sun without proper protection.
To watch safely, observers should always use special "eclipse glasses" or telescopes equipped with solar filters.