1. Monday October 15, 2012 (Asteroids; WS - Asteroids)

2. The Launch Pad Monday, 10/15/12 Identify this object. Uranus

3. The Launch Pad Monday, 10/15/12 Identify this object. Neptune

4. The Launch Pad Monday, 10/15/12 Identify this object. Triton

5. Announcements

6. Assignment Currently Open Summative or Formative? Date IssuedDate Due Date Into GradeSpeed Final Day Quiz 6S110/5 10/19 Quiz 7S210/12 10/26

7. Recent Events in Science Felix Baumgartner Jump Successful! http://www.youtube.com/watch?v=VCqnQq86f kY&feature=related Watch the Videos http://www.youtube.com/watch?v=U5upOFxxvJM

8. Dr. Frank Summers Space Telescope Science Institute March 28, 2008

10. Asteroids Most asteroids lie between the orbits of Mars and Jupiter.

11. Asteroids Asteroids are small bodies – the largest is Ceres, which is about 620 miles in diameter.

12. Asteroids Some asteroids have very eccentric orbits.

13. Many of the impacts on the Moon and Earth were collisions with asteroids. Asteroids

14. They usually have irregular shapes and their origin is uncertain. Asteroids

15. Humans have landed a spacecraft on the asteroid Eros. Asteroids

16. Asteroids in History In 1596 the German astronomer Johannes Kepler was drawing up a geometrical scheme for explaining the orbital spacing of the planets, and was also establishing his three laws of planetary motion. Both these activities made him realize that there was a gap in the solar system between the orbits of Mars and Jupiter where he would have expected to find another planet.

17. Asteroids in History However, it took another 200 years before another planet was found, and it wasn’t in the gap between Mars and Jupiter, it was much further away. The planet was discovered by William Herschel in 1781 and was named Uranus.

18. Asteroids in History Even more interesting was the fact that it obeyed a ‘law’ that had been proposed nine years earlier by Johann Daniel Titius and Johann Elert Bode, as a result their proposal was considered to hold true. Their ‘law’ suggested that each planet should be found about 65% further away from the Sun than the previous planet.

19. Asteroids in History Having looked at the distances of the planets then known, it was easy to see that the gap between Mars and Jupiter (as Kepler had spotted) was too big – there should have been something in-between.

20. Asteroids in History In August 1798, a group known as the ”Celestial Police” formed to search for this missing planet. Among these was German astronomer Heinrich Olbers, who discovered the second known asteroid, Pallas. Pallas was the goddess of wisdom, courage, inspiration, civilization, law and justice, just warfare, mathematics, strength, strategy, the arts, crafts, and skill.

21. Asteroids in History Incidentally, the first asteroid discovered was Ceres on January 1, 1801 by Giuseppe Piazzi. It was the first asteroid to be identified, though it was classified as a planet at the time. It is named after Ceres, the Roman goddess of growing plants, the harvest, and motherly love.

22. In a letter to a fellow astronomer, Olbers put forth the first theory of asteroid origin. He wrote, “Could it be that Ceres and Pallas are just a pair of fragments of a once greater planet which at one time occupied its proper place between Mars and Jupiter?” Olbers reasoned that the fragments of such a planet would intersect at the point of the explosion, and again in the orbit directly opposite. He observed these two areas nightly, and on March 29, 1807, discovered Vesta, becoming the first person to discover two asteroids. Asteroids in History Vesta is the Roman goddess of the hearth, home, and family.

23. Asteroid Mathilde Mathilde is a main-belt asteroid about 30 miles in diameter that was discovered by Johann Palisa in 1885. It has a relatively elliptical orbit that requires more than four years to circle the Sun. This asteroid has an unusually slow rate of rotation, requiring 17.4 days to complete a 360° revolution about its axis. This asteroid was visited by the NEAR Shoemaker spacecraft during June 1997, on its way to asteroid 433 Eros. During the flyby, the spacecraft imaged a hemisphere of the asteroid, revealing many large craters that have gouged out depressions in the surface.

24. Asteroid Gaspra Gaspra is an asteroid that orbits very close to the inner edge of the asteroid belt. Gaspra was the first asteroid ever to be closely approached when it was visited by the Galileo spacecraft, which flew by on its way to Jupiter on October 29, 1991.

25. Asteroid Eros 433 Eros is a near-Earth asteroid (NEA) discovered in 1898, and the first asteroid to be orbited by a probe, in 2000. It is about 21 × 7× 7 miles in size. Eros is a ”Mars-crosser asteroid”, the first known to come within the orbit of Mars. Objects in such an orbit can remain there for only a few hundred million years before the orbit is perturbed by gravitational interactions. Dynamical integrations suggest that Eros may evolve into an “Earth-crosser” within as short an interval as 2 million years. It is a potential Earth impactor, comparable in size to the impactor that created the Chicxulub Crater and led to the extinction of the dinosaurs.

26. Asteroid Impact Sites on Earth

27. Manicouagan, Quebec, Canada a 200-million-year old eroded impact structure

28. This impact crater in Winslow, Arizona, is one of about 200 on Earth. At 50,000 years old, it’s also one of the newest. The crater is 1.1 km (.7 mi) in diameter and 150 m (495 ft) deep. The meteorite that made it weighed 100,000 tons. Most meteorites that hit the ground are too small to leave a crater, but anything larger than a house explodes just before or during impact and leaves a crater that is much larger than itself. Photo © Charles and Josette Lenars/CORBIS

29. Asteroids Worksheet Go to www.irvingisd.net/nimitz Click on Faculty. Scroll down and find my name – click on Website. When on my website, click on Earth and Space Science Class Notes. Scroll down to today’s date and download today’s PowerPoint. Use the PowerPoint to complete this Worksheet on Asteroids.