Anonymous
Anonymous asked in Science & MathematicsAstronomy & Space · 1 decade ago

Do you think so? - Asteroids?

see this http://www.youtube.com/watch?v=1D1zFBWBqhw

Youtube thumbnail

&mode=related&search=

is this a real CNN report or only a montage

Update:

Please, could you tell me what level of education do you have?

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  • DaM
    Lv 6
    1 decade ago
    Favorite Answer

    There is indeed an asteroid, Apophis 99942, that will be making a close approach in 2029. It will not hit us.

    "The asteroid (99942) Apophis (previously designated as 2004 MN4) will have a very close approach to Earth in 2029. The observations collected in the months of December 2004 and January 2005 by professional and amateur astronomers have provided enough information to exclude the possibility of an impact in 2029. " http://newton.dm.unipi.it/cgi-bin/neodys/neoibo?ri...

    Source(s): some college
  • nick s
    Lv 6
    1 decade ago

    Yes, Dana M is educated enough to recognise CNN hype when he sees it.

    It is descpicable all this scaremongering. There isn’t one asteroid in the future known to have more than a 1 in 40,000 chance of hitting Earth.

    Have a look at http://neo.jpl.nasa.gov/cgi-bin/neo_ca

    You can see what’s coming into the future. Use a search for <10LD. You will get all the future asteroids that are known to approach within 10 lunar distances (about 4 million kms).

    There are no secrets. You will see that Apophis in 1929 will approach within 0.1 LD, which is about 38,000 kms. The Earth is about 13,000 kms wide, so that is close enough, but try this:

    Draw a circle 13 cms wide, then at the same center draw one 38 cms wide. You will see there is a lot of space between the small circle and the big one.

    So, relax. And don’t get caught up in hype.

    Source(s): Science author
  • 1 decade ago

    It may have been a real report, every once in a while asteroids come close to us. The scary thing is, if we get hit by an asteroid, we probably won't see it coming (I have this directly from the people who study asteroids and look for dangerous ones, namely the spacewatch team).

    Source(s): Astronomy and Physics major (in the middle of it)
  • 1 decade ago

    The IAU Minor Planet Center lists 4677 close approach objects at present. "Close" is somewhat arbitrary. To make this list an object has to have a perihelion distance (closest point to the Sun) less than 1.3 AU (astronomical units or Earth-Sun distances). They range in size from objects like Eros and Ganymed (that's (1036) Ganymed not Ganymede the moon orbiting Jupiter) which are 10-30km across down to objects like 2004 FU162 and 2003 SQ222 which are around 1 meter across. For most of the objects we don't know much about what they look like, we usually infer their size based on how bright they are. The number of objects in a particular size range probably varies exponentially (well the distribution follows a power law). Thus there are 3 in the 10 km class, around 60 in the 5 km class, about 1000 in the 1 km class, something like 100-200,000 in the 100 m class and perhaps 1 million objects of around 50 m that could cause something like the Tunguska explosion of 1908. Many of these numbers are estimates based on what we've seen so far and estimates of how frequently the smaller, fainter objects come into positions where we can see them with the equipment currently in use. The major surveys operating at present (LINEAR, NEAT, LONEOS, Spacewatch and the three sites associated with the Catalina survey) are mainly designed to find the objects around 1 km in size. Of course they find many smaller objects, there are so many more of them around and this makes up for their low probability of being in a position where we can see them. Depending on how you count, we've found about 700-800 of the estimated population of 1000 1km sized objects.

    Objects with perihelion distances less than 1.3 AU may still not come very close to Earth. Another classification is Potentially Hazardous Object (PHO). These are objects that come within 0.05 AU (about 20 times the distance to the Moon or about 7.5 million km) and which have absolute magnitudes brighter than 22. Assuming a standard reflectivity this means objects around 100 m or a bit larger. Objects smaller than this are believed to be more likely to explode in the air (as at Tunguska) than reach the ground.

    The Minor Planet Center lists 862 PHOs at present, other sites have slightly different numbers. The recent NASA report to Congress estimated a total of about 20,000 PHOs.

    It is also important to realise that the main point of the surveys is to find the bigger objects that are out there and track their orbits so we can project their motion out into the future. That way we can find out early if we are going to be unlucky and have a big asteroid strike in the next 100 years. It is not the job of the surveys to find the next asteroid that will hit us. First of all, little ones hit all the time like that one in Norway in 2006. Secondly, even objects like that responsible for Tunguska, which may only hit us every 1000 years or so, are very unlikely to be found before they hit us with the current equipment. More powerful surveys like Pan-STARRS and the LSST are in the planning stage and could increase our chances of finding these smaller objects before they find us.

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