2. LookThinkDiscussAgreeShareWrite What is today's lesson about?

3. Learning Intention COLLISIONS Learning objectives All (must) describe the theories of how the moon formed, and why the impact theory is most likely describe the theories of how the moon formed, and why the impact theory is most likely Most (Should) explain the difference between an asteroid, meteor and meteorite and the threat they pose to the planet explain the difference between an asteroid, meteor and meteorite and the threat they pose to the planet Some (could) Explain the theory of ELE that lead to the extinction of the dinosaurs Sunday, 17 January 2016

4. Time= 7 mins End 1) Capture Theory -The Earth gravity “captures” a moon adrift in space o Pros: well, it's not impossible o Cons:  it's very unlikely (more likely to crash into earth)  The moon would have a lot of kinetic energy it would have to lose in someway Pros: Lots of material around in the early solar system so it is possible Cons: Why would the Earth and Moon have different compositions (i.e. why is the moon deficient in Iron)?  Earth-Moon system has a more angular momentum compared to other planets and moons. 2) Accretion/Double planet theory - During the formation of the Solar System both the Moon and the Earth were formed at the same How did the moon form? (1)

5. 3) Spinning/ Fission Theory - A fast spinning Earth "gives birth" to the Moon. Pros: Density of Moon similar to that of the outer layers of the Earth o Cons:  Moon should be orbiting along Earth's equator; it's not.  Composition of Moon rocks dissimilar to that of the Earth's surface.  Earth would have to have been spinning extremely fast for this to happen Pros:  Collisions happen (but this is a whopper: Mars sized or bigger!)  Explains lack of an Iron core. Simulations confirm the possibility. Explains tip of the Earth's axis!Simulations o Cons: Why just one moon? Currently, the Impact theory is the most favoured. But questions remain, and work is ongoing... 4) Impact Theory - A large rock/ asteroid hits Earth, ejecting material which then groups together (under the force of gravity) to form the Moon How did the moon form? (2)

6. ACTIVITY 2 Time= 20 mins End Threats to Earth WHY THE EARTH IS AT RISK There are thousands of Asteroids and comets in the solar system These objects are attracted to the sun by its gravitational pull If one of these objects passes close to the Earth it will get sucked in by the earths gravitational pull. Most objects are small enough that they burn up as they enter the atmosphere. We call them shooting stars The part that does not burn up is called a meteorite and makes a crater when it hits earth. However, if the meteor is big enough (say 50m across) it will cause a lot of damage. Big meteors could cause the following problems 1.Large crater (if it hits land) This is a BIG problem if it hits a town or city!! 2.Fires- Hot rocks thrown into the air which then fall back to earth 3.Dust thrown into the atmosphere- if there was enough dust, it could block out the sunlight, this would cause instant climate change. this in turn would killing plants and animals possibly causing mass extinction. 4.Shockwave- knocking down buildings and trees and starting fires 5.Earthquakes and Volcanoes erupting as a result of the impact 6.Greenhouse effect- fires release a lot of carbon dioxide into atmosphere 7.acid rain 8.If the meteor lands in the sea, it would create a massive tsunami. In your own words explain the risks to the earth if an asteroid hits

7. ACTIVITY 3 Time= 12 mins End EXTINCTION OF THE DINOSAURS Scientists believe that 65 million years ago an object approximately 10km in diameter hit the earth just off what is now the gulf of Mexico The object would have hit at a speed of approximately 100,000 km/h. The initial blast (equivalent to 10 nuclear bombs) would have destroyed everything within a radius of between 400 and 500km. At the same time large fires would have been started by the shock wave, which would have travelled several thousand miles. Trillions of tons of debris (dust, gases and water vapour) would have been thrown into the atmosphere. Many enormous tidal waves would be started causing even more damage. The impact would also have started a chain reaction of earthquakes and volcanic activity. In the days and weeks following the impact the cloud of debris would have been carried over large distances causing months, (possibly years) of darkness. This would also (initially) have caused temperatures to drop dramatically. However, The fires (and increased volcanic activity) would have caused a massive release of Carbon dioxide. This in turn would have caused a greenhouse effect increase raising temperatures and leading to chemical reactions that would resulting in the formation of acid rains. Storyboard the main events of the death of the dinosaurs

8. NEAR EARTH OBJECTS (NEO) We now realise that any large asteroid or meteor is a threat to earth and our way of life. Many of these objects come from the asteroid belt (which is between Mars and Jupiter) Any asteroid that gets knocked out of its orbit will head towards the sun. If it crosses the earths orbital path it will hit earth So It is important that we LOOK for any objects that may cross the earths path If we get enough warning we MIGHT be able to do something about it. This is a NASA estimate of the frequency of asteroid/meteor hits 1.Pea-size meteoroids - 10 per hour 2.Walnut-size - 1 per hour 3.Grapefruit-size - 1 every 10 hours 4.Basketball-size - 1 per month 5.50-m rock that would destroy an area the size of Manchester - 1 per 100 years 6.1-km asteroid - 1 per 100,000 years 7.2-km asteroid - 1 per 500,000 years ACTIVITY 4 In your own words explain what a near earth object is and what the likelihood of one hitting earth is

9. YESI have enjoyed the lesson and learnt a lot and completed my class activity. SOMEI have understood some of the work and haven’t finished it all NOI have found it difficult to learn today and I have done very little work

11. Science Department Marking your work S trength Say what you have done well T arget This is something that you could do to improve your work and/or take the next step forward. E ffort a comment about your overall effort here. Sometimes this will be a number. 1- Excellent 2 – Good effort 3 – Satisfactory 4 - More effort needed P upil comment write your own pupil comment. It should show how well you think that you have understood the work.