Why asteroids are cool They are leftovers from the formation of the solar system – Studying them tells us about the origin of the solar system and the Earth
1 st birth place of Asteroids The Asteroid Belt: between Jupiter and Mars. Asteroids can collide and get redirected toward Earth. Note the Belt’s size
2 nd birth place of Asteroids: Kuiper Belt Another band of asteroids outside outer planets. – What is the pink band? Figure: Objects in the main belt are colored green, while scattered objects are colored orange. The four outer planets are blue. Neptune's few known Trojan asteroids are yellow, while Jupiter's are pink. The scattered objects between the Sun and the Kuiper belt are known as centaurs. The scale is in astronomical units. The pronounced gap at the bottom is due to obscuration by the band of the Milky Way.
Most famous asteroid: A 10 km asteroid wiped out 50% of the Earth’s species, including dinosaurs, 65 mya
ash from impact blanketed the Earth …then blackness…then coldness
Deep Impact Trailer The resultant Chicxulub Crater is 110 miles in diameter
Meteor Crater is 2.5 miles in circumference. It was made by a meteor 150 ft. in diameter travelling at 65,000 miles/hr.
#2: Comets A comet is an icy, dusty body orbiting the sun; a.k.a. “dirty snowball”
Comet Anatomy: Note the two distinct tails: light blue for gas (ion), grey for dust What is the tail(s) direction relative to the sun? Relative to motion?
Comet orbit Watch 2 animations of comet’s path around the sun in the following link: http://www.classzone.com/books/earth_science/terc/content/visualizations/es2706/es2706page01.cfm?chapter_no=visualization Notice: – Orbit shape: – Speed: – Tail direction:
Comet source: The Oort cloud is the birthplace of all comets. – It is a shell of debris nearly a quarter of the distance to Proxima Centauri, the nearest star to the Sun. – Pluto is less than one thousandth the Oort cloud's distance. – the Oort cloud defines the gravitational boundary of the Sun.
#3: Meteoroids A meteoroid is a small sand to boulder sized particle of debris in the Solar System. Meteor: The visible path of a meteoroid that enters the atmosphere, a.k.a. "shooting star" If a meteoroid reaches the ground, it is then called a meteorite.
Meteor shower source: when the Earth passes through a trail of debris left by a comet. Debris burns up in atmosphere, glowing brightly
2 meteors in a shower. Photographed with a camera with an open shutter. What’s in the middle of the picture?
To Learn More… About – Minor Planets Minor Planets – Solar System Solar System – Sun Sun – Meteoroids Meteoroids – 951 Gaspra 951 Gaspra – Trojan asteroids Trojan asteroids – Centaurs Centaurs – Astronomical units (AU) Astronomical units (AU) – Milky Way Milky Way – Small Solar System Body Small Solar System Body – Comet coma Comet coma – Comet tail Comet tail – Comet’s nucleus Comet’s nucleus – Elliptical orbits Elliptical orbits – Oort cloud Oort cloud – Meteorite Meteorite – Meteor shower Meteor shower Just Click!
Extinction Level Asteroid What is the best way for humanity to survive a killer asteroid? If only some can survive, say 300, create a plan for deciding who lives.