A comet be able to be of sun size.
it might be the brightness of the comet.
astroid
snowball
A large comet or asteroid striking earth
No. A Comet is a relative large body that is seen for many days. A meteor is the flash of a tiny bit of sand or gravel, usually left over from a comet.
a large lump of rock that is heading for a planet
A comet is a large lump of ice, dust and stones hurtling through space. If it passes close to the Sun, the water vapour given off, forms the tail of the comet.
a comet is much more powerful because it is incredibly fast and it's large enough to be in orbit of the sun.
The sun might explode some huge comet might it the earth
Would the impact of a comet on the Earth cause earthquakes? Possibly; it would depend on where the comet hit. But depending on the size of the comet that struck the Earth, the results might vary from "merely" very terrible indeed to absolutely catastrophic; The impact, the fallout, the tsunami (if a water strike) and/or the "nuclear winter" darkening of the skies with dust and debris would dwarf most conceivable earthquakes. Let me put it this way; if a large comet strikes the Earth, the last thing people will be worrying about would be an earthquake.
gravity pulls it towards the large object
There isn't a Susans comet yet (that I know of anyway!), so you will have to get your telescope ourt and start scanning the skies. If you find a new comet you might be allowed to name it Susan.