Is a comet bigger than an asteroid?

When it comes to the nucleus (the solid body itself), then there is no answer to that question. There are small comets and large comets, as well as there are small asteroids and large asteroids. read more

Of course comets don’t just consist of a solid nucleus, but the gas cloud that surrounds them, together with their tail, is orders of magnitudes larger than the nucleus. Some comet tails can be dozens of millions of kilometres long, making them the largest structures in the entire solar system. read more

Asteroids and comets have a few things in common. They are both celestial bodies orbiting our Sun, and they both can have unusual orbits, sometimes straying close to Earth or the other planets. They are both “leftovers” — made from materials from the formation of our Solar System 4.5 billion years ago. read more