Comets-Asteroid-and-meteors-lecture-slides.ppt

lecture slides

1. Comets and Asteroid

2. What do we know about… Asteroid Comets Meteor

3. Characteristics Comet Asteroid Origin Kuiper Belt and Oort Cloud Main Asteroid Belt Shape Varied/ Irregular Varied/ Irregular Size range of diameter (kilometer) 1 – 10 (nucleus only) 1 – 100++ Chemical composition Ice (frozen water); Frozen gases (ammonia, methane, and carbon dioxide); other organic compounds ( Carbon-containing compounds) Silicates ( olivine and pyroxene), iron, nickel Orbit Highly elliptical More rounded Orbital period (years) 75 to 100,000++ 1 - 100

4. Origin Oort Cloud located beyond our solar system. Where most comets usually came from. long – period comets - takes 200 to hundred millions of years to complete their orbit around the Sun.

5. Kuiper Belt located beyond Neptune’s orbit. Where short period comets came from. short – period comet - takes 75 – 200 years to complete their orbit around the Sun. example: Comet Halley- most famous comet of the 20 th century and the only known short – period comet ( 75 – 79 years).

6. Main Asteroid Belt located between planet Mars and Jupiter. Theorized by scientists to be remnants of a planet that did not completely form.

7. comet asteroid

8. C omet A steroid

9. The composition of a comet is important in helping scientists understand how Earth has liquid water, which in turn made the planet livable. During Earth’s formation, s cientist theorized that the planet must have been too hot to have liquid on its surface, the early impact of comets on Earth brought liquid water to the planet. The chemical composition of an asteroid is important in providing clues for scientists to discover more about the chemical composition of Earth and the other planets in the Solar System. Scientists’ belief that Earth, other planets, and asteroids are essentially similar in composition. They are called minor planets or planetoids.

10. Alvarez Hypothesis ( Luis and Walter Alvarez) - proposed that an asteroid with approximately 10 km. in diameter ( as big as Mt. Everest) made an impact with Earth 65 million years ago. They thought that the impact caused materials to be thrown up in air, thus blocking sunlight, and bringing about a period of winter long enough to cause a mass extinction of plants and animals, including the dinosaurs. Further, this event ended the Cretaceous Period and ushered in the Tertiary Period.

11. Chicxulub crater   is an  impact crater   buried underneath the  Yucatán Peninsula in   Mexico . the crater is more than 180 km.(manila to quezon ) in diameter and 20 km. (manila to alabang ) in depth.

12. size is as big as Mt. Everest - has a speed of 80,000 km/mile (20 times faster than the bullet) - energy released is 1 million nuclear bomb Iridium – gray clay found in the boundary of rocks layer on the Earth’s crust all over the world. - a metal belonging to the Platinum family which is very rarely found in Earth’s crust, but more abundant in the mantle and core. It is also abundant in our solar system.

13. Baringer Crater an im pact crater buried in Winslow, Arizona. (50,000 years ago) the crater is 1 mile wide and 570 ft. deep

14. Meteoroid, meteor, and meteorite: How are they related?

15. Meteoroid is a broken up rock and dust from either a comet, asteroid, the Moon, or from Mars. it can be as small as a grain of sand or as big as a boulder.

16. Meteor a light phenomenon or a streak of light that occurs when a meteoroid burns up as it enters Earth’s atmosphere. also known as a shooting star or falling star. it moves swiftly and seems to fall on the ground

17. Meteorite fragments from the meteoroid survive and makes it to the ground.

18. Meteor shower annual light phenomena characterized by many meteors appearing in the sky in a short period of time . happens when Earth passes through the orbit of a comet (or an asteroid) where fragments and dust remain in orbit and orbits the Sun as well while Earth goes around the Sun.