Transit (2004)
On 8 June 2004, the planet Venus, as seen from Earth, passed in front of the Sun to
produce an effect known as a transit. Astronomers have used this very same phenomenon
to detect a few planets around other stars, such as HD 209458. As a planet passes in
front of its star, the star's light dips just a little — but it can be measured,
and the presence of a planet thus inferred.