is it true that if a comet was guna hit the earth we would have 2 years in advance notice?

Answer 1

No, not true at all. You may have less than than, but also you could get a lot more than 2 years.
That depends on the size of the comet (bigger ones would be detected sooner than smaller ones) and the speed it is coming (faster ones would give less of a warning). Moreover, if a comet has an orbit than can pass close to Jupiter and Saturn, its orbit can get modified in nearly impossible to predict ways, so a comet that could be projected to pass far from Earth could be redirected with fairly short advanced warning. This is highly unlikely, as the Earth would have to be in a very specific position in its orbit, and an Earth orbit crossing comet would then possibly go through several orbit before it impacts; in that case we would have perhaps centuries of advanced warning.

The ones that could slam with short advanced warning would then most likely be currently undiscovered comets.

Answer 2

We would not necessarily have any notice that a comet was coming. Like some people have said, we may have years, months or even decades; or we may have virtually no warning at all.
The problem today is not necessarily that we know a comet may be coming, but what to do if one was on track to hit Earth. Despite the Hollywood idea that we can prevent such a casatrophic event, our resources at this point are very limited in deflecting or destroying a comet before it hits Earth. Comets are also traveling at immense speeds, only further complicating the process of intercepting one. In fact the Shoemaker-Levy comet that collided with Jupiter in the 1990's was traveling at 40 miles per second. At the rate, it would have been able to travel across the entire United States in just under a minute.

Answer 3

We might have some days or weeks advance notice of a comet, because comets tend to be so visible. Comets are also somewhat diffuse, and are not likely to do serious damage to the earth.

The thing that is likely to do real harm or "destroy all life on earth" or whatever is an asteroid or a large meteorite, and at present the chances are slim that we will have any advance warning at all.

Bang!

Answer 4

maybe with a standard comet, with satelite technology and calculas we should be able to detect comets that are very far away. However, if there should be a comet that travels at a speed faster than we can comprehend at this point. we will be doomed and have no warning. Since if it travels close to the speed of light, the comet will be here at the moment that the light of the comet finally reaches the telescope... so there could be a comet headed for us right now that will wipe us out in an instant, and we cannot see it because it is just moving too darn fast. Your life can end at any minute =D have a nice day

Answer 5

Not nessicarily. Small objects "hit" the Earth every day. Most burn up in the atmosphere but some actually impact.

As a comet approaches the sun, it typically grows brigher, allowing us to see it. If a large undocumented comet were heading our way, chances are we'd see it perhaps a few weeks or months in advance.

An asteroid is another situation. If a large asteroid, large enough to destroy a city, were heading our way, we might never see it. Depending on what the asteroid is made of, it might not be bright enough to draw any attention. Or, it could approach from the direction of the sun, making it less likely to be detected.

Infact a few good sized asteroids have passed between the Earth and moon and we only detected them on their departure from out vicinity.

Answer 6

i don't think we would have that much time... first the comet would have to be spotted by an observer. Most comets are not spotted until they reach the orbit range of Saturn or Jupiter. So if a comet was spotted in that region and was determined to be on a collision course with earth you would have about a 2 month notice... scary thought huh

Answer 7

Several "small" comets that passed close to the earth in recent years came with only a few weeks of warning---comets IRAS-Araki-Alcock (1983) and Hyakutake (1996), for example. There is no systematic, managed operation for finding such objects, and detecting them depends on someone familiar with the sky seeing them by chance. I suspect an object like the one that caused the Tunguska event could come in with only a few minutes warning.

Answer 8

If the comet had been observed for years beforehand, the warning time could be measured in decades. If it had never been observed before its last orbit before hitting earth, it would depend on how big it was - from months to no warning at all.

Answer 9

Not sure if there's always the same amount of warning, but there are people who are specifically tasked to look for comets and asteroids, and other "near-Earth objects."

Sometimes the warning comes dozens of years before the actual event, as indicated by several discoveries of potential near-misses of the Earth by asteroids. Other times, the warnings might not come at all, particularly if the asteroid is small and dark.

Answer 10

Maybe...if and astronomer saw a meteorite and thought it looked like it was gonna hit the Earth, we probably would have much time.Unless, of course, the used radar and saw that it would take 2 years.But 2 years...that's 2 orbits around the sun so no we wouldn't have that much time.