What is a comet?

Don't ever be afraid if you hear about a comet coming! Some people believe, comets bring havoc and disaster to earth, but that's of course, not true. A comet in the sky is a great look and something you should know more about.

---

We see the sun, the moon and the stars in the sky, on pictures or through a telescope. Very rarely, perhaps only once in a lifetime, a comet visible to the naked eye appears between the stars.

---

The comet may first look like a bright spot or a little shining cloud in the clear sky at night. We can see it particularily well in dark places like the mountains or at the seashore. For days and weeks it slowly wanders on its orbit through the constellations.

---

The comet is not a star or meteorite but a huge lump made of ice and dust. It is far bigger than our house, it is as large as a whole town or city. Compared to our earth, however, it is still nothing but a grain of dust in the universe.

---

The comet travels at nearly unbelievable speed on its course. Like the planets do, it orbits around the sun. As the comet comes nearer to the sun, its ice begins to evaporate. The comet's nucleus is then wrapped in a cloud of gas and dust.

---

We see this cloud as the comet's tail in the sky at night. It is illuminated by the sun and shines. Some comets become so bright, that we can even see them at daytime. The tail always shows away from the sun.

---

So far still nobody really knows what the surface of the comet looks like. We can however imagine, that the comet's landscape would seem very, very strange and gloomy to us.

In a few years' time scientists will land a probe on a comet, will photograph everything and will even return a handful of a comet's dust to earth.

After some weeks the comet in the sky begins to shrink and fades. Soon it disappears in the depths of space and is no longer visible. Some comets may return only after hundreds or thousands of years to please the observers' eye on earth again.