Every year, the Earth passes near the path of the comet, and the debris left behind by Swift-Tuttle shows up as meteors in our sky.

Rosetta's probe, Philae, has successfully landed on the comet 67P/Churyumov–Gerasimenko.

If the comet nucleus is pulled into an orbit which carries it close to the Sun, the solar heat will cause the outer layers of the icy nucleus to evaporate.

Tycho Brahe observed the Great Comet of 1577.

Comet Siding Spring was discovered in 2013 by astronomers at the Siding Spring Observatory in Australia.

Since Comet Siding Spring's discovery, astronomers have observed it with many telescopes, including the Hubble Space Telescope.

More rapid than eagles his coursers they came, And he whistled, and shouted, and called them by name: "Now, Dasher! now, Dancer! now, Prancer and Vixen! On, Comet! on, Cupid! on, Donder and Blitzen! To the top of the porch! to the top of the wall! Now dash away! dash away! dash away all!"

Comets start to disintegrate as they approach the sun, and that disintegrating material may or may not form a "tail" that helps make the object more visible.

That's how he discovered the comet.

Rebecca also, when she saw Isaac, lighted off the camel, and said to the servant: Who is that man who cometh towards us along the field? And he said to her: That man is my master. But she quickly took her cloak, and covered herself.