Transit of Venus

A transit of the Sun occurs when an inferior planet (the two inside the Earth's orbit: Mercury and Venus) are seen to cross the Sun's surface. These are quite rare because the orbits of those planets are inclined and rarely line up with the Sun.

Transits of Venus are particularly rare and occur in pairs with about a hundred years between them, so I am lucky to have seen two. This is the 6 June 2012 transit, the second one I have seen, which I viewed from Dunedin, New Zealand. I made a trip to the outback of Australia to view the first.

I used a Canon EOS500D digital SLR with a Canon 75-300 lens set to 300m (equivalent about 450 mm) for this. I used a solar filter over the front of the lens to reduce the light.

Venus is the larger black circle near the bottom of the Sun. During a transit, Venus is always about 3 times closer than the Sun, so you can see how huge the Sun is compared to the planets (Venus is about thew same size as the Earth). About 10 sunspots are also visible in this image. Remember they are three times further away than Venus, so they are a similar size to the whole planet!