A transit of Venus occurs when the planet passes between the Sun and Earth, obscuring a small portion of the Sun’s disk. In 1639, English astronomer Jeremiah Horrocks made the first observation of such a transit by using a telescope to focus the Sun’s image onto a white screen and watching as Venus’s shadow, appearing as a small black disk, passed across it. These observations allowed him to estimate the distance from Earth to the Sun more accurately than ever before. How close was his estimate? Discuss
Source: The Free Dictionary