How long would you be able to see a large meteor headed for earth before it hit the earth?

Answer 1

Well in fact, its not a meteor before it enters the atmosphere - so I suggest you rephrase your question to one that includes an "asteroid".

However I will answer it in terms an of an asteroid.

According to Einstein's theory of general relativity (which unless you have studied it at University level, I will not bother to explain it...) the parabolic curve of a suggested asteroid heading towards Earth could be predicted years before impact. However seeing through the naked eye would be for around 1-3 days for an asteroid of around the size of New York (which I believe is your question)

This is due to the extensive trail it would leave, and its obvious reflection from the sun. Although you may say it is travelling at speeds up to 80% of the speed of light, this is relatively slow in terms of "space travel", and the comet would initially appear as just a dot in the sky which would you could initially see, but would only be the size of another star in the sky and thus indistinguishable, so the untrained eye would not notice it.

If you would like a more detailed mathematical response I would happy to provide an elliptical integral formula derivation of this?

Thanks

Answer 2

Strictly speaking, a "meteor" is the streak of light; the object that is causing the meteor has its own orbital motion about the Sun and by the time it is burning in the Earth's atmosphere has been affected by the Earth's gravity. Since the Earth is also in motion around the Sun, there are three effects to consider. Sometimes these largely cancel each other out (e.g., the object and the Earth are moving in the same direction) and the meteorite makes a relatively "soft" landing.

Answer 3

When a meteor enters the atmosphere, we can make a fairly educated guess as to the temperature it reaches. Rock melts at 1200ºC and Iron melts at 1536ºC, as many the the heavier meteors are made from these and other elements, it is safe to assume the temperature range is between these two points.

Those that burn up must reach the minimum of 1200ºC. If a meteor Hits the earth its becomes know as a meteorite. It might have started out as small boulder but by the time it hits it could be the size of a football or smaller.

Answer 4

It depends on the size of the meteor. Most will disintegrate on impact, causing some local damage, but others can have catastrophic outcomes. It is now believed that a meteor impact, off the coast of Mexico, threw up so much debris into the upper atmosphere that the resulting climatic disruption caused the extinction of the dinosaurs. The meteorite itself is thought to be buried in a crater that it made in the bay of Mexico.

In 1908, there was an impact by comet or meteor in the Tunguska Region of Eastern Siberia. It is thought that the bolide exploded at low altitude (5 to 10 km) rather than actually hit the earth and no impact crater has been found. However, it is classified as an impact event. The explosion, flattened 2000 square kilometres of forest.

Answer 5

Meteoroids orbit the Sun like every other object in the solar system.

Meteors are meteoroids that enter the Earths atmosphere but fail to hit the ground. If they enter the atmosphere at a very shallow angel they can end up passing through and go on to continue to orbit the Sun. Most however burn up in the atmosphere before they hit the ground.

Answer 6

Technically they can be said to orbit the sun because every thing in our galaxy does, but; meteoroids have been found to have many different orbits, some clustering in streams called meteor showers which are often associated with a parent comet, or Asteroid while others are completely sporadic being left in the wake if a passing Asteroid and then being intersected by earth's orbit. When we talk about meteors, we talk about small objects (usually less than 1 m in diameter) that are captured by the gravitational attraction of the Earth and fall into its atmosphere. The meteor itself is the luminous tail that is left behind the infalling object (meteoroid) and that is due to the ionization of the air and by the subsequent recombination ofthe ions. Most of the meteors actually disappear. Debris from meteoroid streams may eventually be scattered into other orbits or follow a comet, but still would be technically orbiting the sun.

Answer 7

It's called a "meteoroid" when it is out in space. When it enters the Earth's atmosphere and is heated to incandescence, the bright streak of light is called a "meteor".

If the object survives the fiery passage through the atmosphere and hits the ground, it is called a "meteorite".

Answer 8

Anywhere: it depends on the direction of their motion and on earth's gravity.

Answer 9

It becomes a meteor when it hits earth's atmosphere.

Answer 10

According to all applicable laws of physics. It's difficult to be more precise than that, because the question itself is pretty vague.