Venus spot puzzles experts

The spot was first identified by US amateur astronomer Frank Melillo, from Holtsville, New York.

The spot was first identified by an amateur astronomer on 19 July and was later confirmed by the European Space Agency's Venus Express spacecraft.

Data from the European probe suggests the spot appeared at least four days before it was spotted from Earth.  Source: BBC

This event seems to have happened about the same time as Jupiter was hit by a Comet or asteroid, which is interesting - are they some how related?

Jupiter Hit by Comet: Witnessed by Astronomer Anthony Wesley

On a side note: the planet Venus is visible in the eastern horizon, just before sunrise. It is the bright light in the east also known as the morning star.