Did you hear about the comet to hit earth if we dont change its orbit in 2028 or something>?

Answer 1

Scientists at one point thought that there was a very slight chance that an asteroid might collide with the Earth in the year 2029, but this data was based on a miscalcuation and the scientists who originally reported it recanted.

Answer 2

NASA and other Space Agencies have a mandate to look out for objects that may come close to earth. This is called SpaceGuard. Near Earth Objects (NEOs) are what it studies.

Number of near-earth objects

As of August 31, 2006, 4,187 NEO's have been discovered: 57 near-Earth comets and 4,130 near-Earth asteroids. Of those there are 330 Aten asteroids, 1,613 Amor asteroids, and 2,181 Apollo asteroids. There are 792 NEO's which are classified as potentially hazardous asteroids.

Estimating the risks

There are two schemes for classification of impact hazards:

the simple Torino Scale and the more complex Palermo Technical Impact Hazard Scale

On 25 December 2004, minor planet 2004 MN4 (now known as 99942 Apophis) was assigned a 4 on the Torino scale, the highest rating so far. At 27 December 2004 there was a 2.7% chance of Earth impact on the 13 April 2029.

However, on 28 December 2004, the risk of impact dropped to zero for 2029, but, due to a resonant return possibility the Torino rating for an April 2036 impact rose to 4 in early 2005 and, as of August 2006, has dropped gradually to a Torino rating of 0 (zero). The Palermo rating (August 2006) is −2.25.

Currently, the only known NEO with a Palermo scale value greater than zero is (29075) 1950 DA, which is predicted to pass very close to or collide with the Earth (p≤0.003) in the year 2880. If this collision were to happen, the energy released by a collision with (29075) 1950 DA would cause an extinction event which would destroy most life on the planet. However, humanity has over 800 years to refine its estimates of the orbit of (29075) 1950 DA, and to deflect it if necessary.

NASA maintains a continuously updated web page of the most significant NEO threats in the next 100 years - all or nearly all of which are highly likely to drop off the list eventually as more data comes in enabling more accurate predictions; however, that page does not, of course, include 1950 DA, because that will not strike for at least 800 years.

My Comment:

(1) panic would be premature if calculations are imprecise

(2) any object given a plus rating as a possible Earth-impactor is the studied carefully to determine a more precise calculation of its orbit.

(3) the scientists are on the case and if you are concerned, read what NASA has to say on the webpage referred to.

(4) Beware rumours spread by the internet, they are usually based on old information and old assessments. eg the 2029 collider mentioned above proved on closer examination to not be a collider after all.

(5) Place no trust in Doom and Gloom New Age Predictions of Catastrophe, Especially those based on the writings of mystics or on the Mayan Calendar.

(6) Take seriously what scientists predict "may" happen and take seriously their statements of how likely it is to happen. A probability of 2.7% likely to happen is not large enough to lose much sleep over. And one of (p≤0.003) is 9 times more unlikely than that,

One comet about which questions have been raised is 109P/Swift-Tuttle, last seen in 1992 and not due to reappear till 2126. A New Scientist article in 2005 (see 3rd link) predicted eventual collision with either the earth or the moon but not this millennium. Being more than 100 years away, that won't appear on the NASA page, either.

Answer 3

You mean asteroid 99942 Apophis? It probably never will hit, but there is still a very small chance (1 in 43,000) that it could return in 2036 and hit then. However, it is quite small and would only cause a local disaster if it did hit, something like the recent tsunami in south Asia.

Answer 4

Why worry about this Comet! We live in a world of sin andshould expect this world to come to an end. So enjoy your life, read to children, or volunteer your services and prepare for the end.