Venus transiting the Sun
by Students at EUC Syd and AGS, Denmark
Since the orbits of the planets Mercury and Venus lie inside Earth's orbit, each can sometimes be seen to transit—meaning pass in front of—the Sun. Transits of Venus are rare, occurring in pairs at intervals of about 120 years. Venus is the same size as Earth, so photos like this one hint at the huge size of the Sun—which, however, is just an ordinary-sized star. Such transits can also happen with planets around other stars and the tiny drop in light can allow astronomers to discover the presence of the transiting planet.