Animation fun!

The animation to the left is a simulation of what scientists say will happen to our continents. They say our continents will shift and "morph" into each other 250 million years from now into a Pangaea Ultima. Of course, no one can really predict exactly what our continents will look like and what will happen to them, but it's a good guess as to what will happen because of the continually shifting plates. What we've been talking about in class is that the reason plates move is because what we think are convection zones of magma under the plates. These convection currents don't necessarily rotate in the same direction, so it makes sense that the continents would move in different directions.

This is how scientists think the continents shifted to their current locations from Pangaea. This is because of, once again, the shifting plates. Evidence for this is the fossils found on the different continents. There are fossils found in the USA that have the same composition and are the same type that can also be found in Europe. The only explanation was that the continents were once together.




http://library.thinkquest.org/17701/high/pangaea/
http://science.nasa.gov/science-news/science-at-nasa/2000/ast06oct_1/

Biography of a Planet

In Ms. Gardner's class we've been talking about the Nebular Hypothesis and accretion. There is evidence of this on the planet Saturn, but there is also problems involving the idea. The evidence of the Nebular Hypothesis on Saturn is the rings around the planet. It is thought that the rings were a satellite that crashed into Saturn, proving that rocks did crash into other planets. Also, it is a Jovian planet (a gas giant) so it's size and diameter work perfectly for this hypothesis. It's said in the theory that the gas giants formed something like the terrestrial planets, but with gases, and since there were so much gas, the planets (Jupiter and Saturn) became huge in size. Once the gas becomes all used up, the planets could grow no longer. Some problems involving this idea on Saturn are the fact that the rings orbit around Saturn in half the time it takes Saturn to rotate. This is a problem because of the planet Mars' satellites. One of them (Phobos) was found to orbit Mars 3 times around as Mars rotates once. It was thought that Saturn would have an explanation for this, but the rings orbited slower. Then a satellite was found orbiting Saturn and it was orbiting the opposite way of the planet's rotation!

http://www.plantanimalmineral.com/universe/the-nebular-hypothesis
http://en.wikipedia.org/wiki/Nebular_hypothesis