Asteroid vs. Meteor vs. Meteorite

There are many things floating out there in our solar system other than our sun, planets, and their moons. But there is usually a lot of confusion of what really to call these things. According to Discovery Education, an asteroid is “one of the many small or minor planets that are members of the solar system and that move in elliptical orbits primarily between the orbits of Mars and Jupiter.” In laymen’s terms, it is any of the small, rocky bodies that revolve around the sun. This can include both comets and meteoroids. So, not all asteroids are meteoroids, but all meteoroids are asteroids.

The vast majority of the asteroids in our solar system are found in the asteroid belt that separates the orbits of Mars and Jupiter, and serves as the dividing line between the inner and outer planets. There are two main thoughts on how this asteroid belt formed. The first is that it was originally a pair of planets or moons that collided with each other. The second and more widely accepted theory is that the asteroid belt is made up of material that Jupiter’s gravity prevented from becoming a planet.

With the large amount of these asteroids floating about, our solar system has become a cosmic shooting gallery. Asteroids can range in size from the size of a golf ball to larger than the state of Texas (Armageddon anyone?) Asteroids of this size are global killers, and it is theorized that this is what wiped out the dinosaurs almost 65 million years ago. The asteroid would have ejected tons of material into the Earth’s atmosphere, blocking out the sun’s light. This would have led to a global climate change, and put a stop to the process of photosynthesis. Without large amounts of plant material, the large herbivore species of the time would have perished very quickly, thus cutting off the food supply for carnivores. Those that did not die off in this manner would not have been able to adapt quickly enough to rapid the decline in global temperatures. A bleak picture of a possible future? It is possible that at some point this may be the fate of mankind, but our asteroid detection and monitoring systems have kept an eye out for any of these planet killers. Our moon is a testament to how close many of them have come.
Moon

But we cannot overlook the fact that these small rocky bodies enter our atmosphere every day, the vast majority no bigger than a bowling ball and most about as small as a golf ball. Any time you see a “shooting star” in the sky, it is actually the friction caused by our atmosphere burning these rocky bodies to dust. Once these meteoroids enter our atmosphere, they are now known as meteors. If these meteors survive their entry into our atmosphere and crash into our planet, they are then known as meteorites.

This video is a rather catchy way of remembering all of this.

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4 Responses to Asteroid vs. Meteor vs. Meteorite

  1. The second, more empirically supported theory, is in fact that the asteroids were never allowed to turn into a planet. This is thought to be the result of gravitational perturbations and orbital resonances (http://en.wikipedia.org/wiki/Orbital_resonance). We generally think this because of two things: 1 – The total mass of the asteroid belt is simply too small to have been a planet and 2 – The individual asteroids have such a varied chemical composition it is highly improbable that they cam from the same planet.

    Also, They might be giants is an awesome band. I’ll be seeing them on September 8th in New Haven, CT. at Toad’s Place. This song is definitely getting requested.

    • rsjones says:

      My kids and I also found it quite interesting how close our solar system came to being a binary system if Jupiter had gained more mass at the very beginning of the solar nebula. This would also mean we would have never existed. Wonders of the universe.

      And my whole junior high’s favorite song by TMBG is ROYGBiV. Whenever we are having assembly, I usually throw that on to get their attention :-)

  2. I was drawn to the section of your article where you talked about the theories surrounding the formation of the asteroid belt. Recently, I read an article in NPR’s Cosmos and Culture blog about how we need to thank our gas giant, Jupiter, for protecting the earth from asteroids (Gleiser, 2011). It sounded logical, and I didn’t give it much thought after that.
    Your article prompted me to look into the matter a little further. I immediately found another article talking about research that seems to show that Jupiter may not be as altruistic as we thought. Although Jupiter does in fact take one for the team from time to time, it is also the main gravitational force that disturbs the asteroids to begin with, thus causing many to move toward the inner solar system. However, they did note that Jupiter does seem to provide protection from dangerous Oort cloud comets by ejecting them from the solar system (Voisey, 2009). It’s such an amazing cosmic balancing act, and we depend on it for our very existence!

    Gleiser, M. (2011). Why you should thank your gas giant planet every day. Retrieved on May 29, 2011 from: http://www.npr.org/blogs/13.7/2011/05/26/136619147/why-you-should-thank-your-gas-giant-planet-everyday?sc=fb&cc=fp

    Voisey, J. (2009) Jupiter- Our silent guardian? Retrieved on May 29, 2011 from: http://www.universetoday.com/46055/jupiter-our-silent-guardian/

  3. Marisa says:

    I always enjoy a great lesson on the wonders of the universe. It makes me think about just how small we all really are. We are a part of something that is much bigger than we, as a society, tend to recognize. I mean…we are floating on a huge, nurturing rock in the middle of outer space! What are we doing here?? =]
    I remember watching a meteor shower as a kid and being completely amazed…still am! (http://stardate.org/nightsky/meteors) It is so interesting to learn that the trails of these ‘shooting stars’ are created by our atmosphere, in a way, rejecting this unknown, potentially dangerous meteroid. It’s like our invisible cosmic shield!
    I hope that learning information like this will help people realize just how big and magical life really is!

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