A comet entering the Earth's atmosphere would be a devastating event, what has become known as an ELE, Extinction Level Event. Basically, the atmosphere that came into immediate contact with the object would heat to the point that it actually burst into flames. The object would continue to heat its surroundings as it continued to fall. Different effects would result in a land fall event and a sea fall event.
The crater formed in a land fall event would be vastly larger than the object itself. Keep in mind that Meteor Crater in Arizona is about a mile in diameter and half a mile deep. The object that dug that big a hole was about the size of a refrigerator. Comets are much, much larger, say the size of Rhode Island. Trillions of tons of soil and rock would be thrown into the upper atmosphere, blocking the sun and causing world wide winter for decades to centuries. Life on Earth would essentially end. The lucky ones would be vaporized in the initial blast. Any on the opposite side of the globe who survived would not last long afterward.
There are several theories of what would result from a sea fall, from the planet cracking like an egg, to 1,000 foot tsunamis raking the globe. In addition to the mud and sea bottom that was thrown into the atmosphere, hundreds of trillions of gallons of sea water would be vaporized as well. The result would resemble the nuclear winter threatened by full release scenarios of the Cold War.
Regardless, either way, the days of Man would end. As would the time of most other life we know.
It is quite common for small meteors to hit the Earth. Larger impacts by an asteroid or comet are also possible but happen much less often.
If an atomic bomb were to hit the Earth's core, it would likely not cause a catastrophic chain reaction or destroy the core itself. The core is composed of molten iron and nickel, which are extremely dense and would absorb much of the energy from the explosion without significantly affecting the Earth's overall structure.
A supernova is an exploding star. The Earth would be instantly incinerated, of course. There is approximately zero chance this will ever happen, though. If there was a supernova near Earth ... it would depend on how near. Betelgeuse is a good candidate for a supernova "soon" (within the next million years or so). Scientists who have modeled supernova explosions don't expect it will have much of an impact. If a star nearer than Betelgeuse were to go supernova, then it might be more serious.
The Earth would suffer little affect. The most we would get is rocks blasted from the moon and made it to Earth although they would be to small for any real damage. The moon would experience a crater in its place.
After you hit a certain altitude, the air would become so thin, it would starve the flame making the balloon rise of oxygen, the flame would go out, and the balloon would come plummeting back down to earth
the earth would be destroyed
a comit will hit earth the impact will completely wipe out life as we know it
It would be better to ask what would happen if Earth hit a star, as stars are much larger than Earth is. The planet would be vaporized by the intense heat.
Since "Planet X" is entirely imaginary, probably nothing at all.
It is quite common for small meteors to hit the Earth. Larger impacts by an asteroid or comet are also possible but happen much less often.
They will hit Earth if, in their orbit around the Sun, they happen to cross Earth's orbit.
it could be the end of the earth
We would all die and we would have to kill each other for supplies so get your shotguns ready.
if its bigger than isle of man it would do a very big impact and damage
Nothing.
An asteroid would hit earth first
wouldn't matter because we would be extinct and no one would be around to worry about it.