The BBC reports on a rare transit of Mercury across the Sun. Mercury is somewhat larger than the Moon, but it’s amazing how small it looks compared to the Sun, as the article points out:
Its smallness impresses two things upon you: the enormous size of the Sun and the vastness of the distances between the planets. Mercury was 91 million kilometres (57 million miles) away, the Sun 150 million km (93 million miles) – scales that dwarf human imagination yet are utterly insignificant in cosmic terms.
