My own Astrophotography
Solar system, asteroids
Asteroid photos is best with longer focal lengths.
The asteroids are in orbits around our Sun, most of them in orbits between Mars and Jupiter.
The first one discovered was Ceres, that was in 1801 and first they believed it was a planet.
50 years later an asteroid and now we call the bigger ones for dwarf planets.
Even Ceres the biggest one is smaller than our Moon.
More to read about asteroids at Wikipedia:
Even it the comets looks to be very far away it happens they come close to us, if just only one of them hit the Earth it's goodbye for us.
Ask the dinosaur how fun that was.