- Locations - Types - Meteors - Impacts

 A small solar system object in orbit around the sun composed mostly of rock  Sometimes called “Minor Planets”

 Near Earth Asteroids: › Asteroids that orbit within the earth’s orbit › NEA

 Mathilde  1950 DA › May hit earth in 2880

 Main Belt Asteroids: › Asteroids that orbit between Mars and Jupiter › AKA Asteroid Belt › Have stable orbits › Largest Asteroid - Ceres

 Trojans: › Asteroids that are trapped in Jupiter’s orbit due to it’s strong gravitational pull › Lagrange points  60 degrees in front/behind Jupiter

 Most asteroids located in the asteroid belt

 C-type  S-Type  M-type

 Composition- Carbonaceous (lots of carbon)  Color-Very dark  Percent- Most common type of asteroid (75%)  Primitive › Unchanged since formation › Can be used to study early solar system

 Composition-Silicate (SiO 2 )  Color-Light in color › easier to see  Percent-Make up 15% of asteroids  Some primitive some differentiated › Geologic activity has changed some of the rocks

 Composition - Metallic  Origin-Metal cores of larger asteriods that broke apart  Color-Bright and reflective  Percent-Rare (5-10%)  Differentiated › Have melted since they formed.

Meteorites and Impacts

 Meteorites: › Small pieces of › asteroids that › hits the earth's › atmosphere

 Meteoroid is a small object traveling through space...it could have once been part of an asteroid  'Shooting Star' occurs when a meteoroid enters the atmosphere. . Meteor Showers occur when the dust particles from an aged comet pass through the Earth's atmosphere  Meteor is the bright fireball seen when a sizeable meteoroid enters the Earth's atmosphere and begins to burn...  Meteorite is the resulting body that has traveled through the atmosphere, survived the entry, and has landed on Earth

 37,000 – 78,000 tons of material fall to the earth each year  Most are dust sized particles  Shooting stars occur when meteriods enter the atmosphere and start ot burn up

 Stony  Iron  Stony-Iron

 Composition – Silicate Rock  Most common type  Hardest to find because it looks like rock  Primitive  Contain Chondrules

 Small organic particles left over from the formation of the solar system

 Composition – Metal (iron and nickel)  Not common type  Easy to find iron meteorites because unoxidized iron does not form on earth  Differentiated Pieces of M-Type asteroids

 Composition – Mix of Silicate and Metal  Very Rare  Easier to find then stoneys because of the iron

 Deserts › Metal detectors easily detect iron › Very little erosion to destroy meteorites

 Antartica › Metal detectors easily detect iron › Very little erosion to destroy meteorites › Meteorites contrast with snow › Moving glaciers push meteorites into piles

 Contrast s, m and c type asteriods  Compare and Contrast stoney, iron, iron- stoney meteorites  Tell me what a meteor shower is

 What are the three types of Asteriods?  What are the three types of Meteorites?

 a. Asteroids have hit the Earth in the past and WILL hit the earth in the future

 Barringer Crater › (1.2 km Diameter)  Manicouagan Impact Crater › (70 km in Diameter(

 Vredefort Crater › (140 km Diameter)  Richat Crater › (38 km in Diameter(

Crater Chain Tycho Crater

 Ejecta Blanket – › a layer of debris surrounding an impact layer  Breccia – › crushed rock underneath the impact site  Tektites: › small glassy rocks that were melted during impact and blown through the air › Found in the Ejecta blanket

 Minerals that get compressed due to impact  Found below the craters

 Small solar system body that orbits the sun  Collections of ice, dust and rocky particles  Different from asteroids because of the tail

 Exhibits a visible coma and tail when it gets close enough to the sun  The tail is a result of solar radiation

 Coma › Streams of dust and gas released from the atmosphere around the comet  Tail › Streams of dust and gas that point in slightly different directions › Dust reflects sun

 Large Spherical cloud of billions of comets  Surrounds the solar system  to AU

 Kuiper Belt › A belt of millions of comets from 30 to 100 AU from the sun › From the orbit of neptune outward › Discovered in 1992

 Quaoar › Distance: 43 AU › Diameter: 800 miles

 Sedna › Distance: 86 AU › Diameter: 1000 miles › Probably has a moon

 Pluto › Distance: 39.5 AU › Diameter: 1470 miles › Has moon: Charon

Similar size and same composition as other KBO’s

Large Kuiper Belt Objects: Eris “Xena” 2400 km Pluto 2320 km Sedna ~1800 km km km Quaoar1300 km

 Comets leave a trail of debris behind them that may be meteor showers

Comets Major annual meteor showers: Shower name Date CometComet Period QuadrantidJan 3 ? ? LyridApril 21 Thatcher 415 yrs Eta aquarid May 4 Halley 76 yrs Perseid Aug 11 Swift-Tuttle 105 yrs Orionid Oct 31 Encke 3 yrs Leonid Nov 16 Temple-Tuttle 33 yrs Geminid Dec 13 Phaethon 1.4

 Comet dust scattered through our solar system that can be seen directly under a dark/clear sky  Can be seen in the east a few hour before sunrise

Importance of studying Comets Since Comets originate at the edges of our solar system, the Sun’s heat and radiation have not affected comets since their formation. Because of this, comets still contain volatile elements from the solar system formation that have been baked out of other objects, such as asteroids and planets. Therefore, comets are important to study. Their volatile elements give us unique information from the formation of our solar system.