What else is in our solar system, besides the sun, the planets, and their moons ?

#1: Asteroids Asteroids: are large rocks in orbit around the Sun Between size of meteoroids and dwarf planets 951 Gaspra -18x9km (first asteroid close-up)

Why aren’t they round?

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

1st birth place of Asteroids The Asteroid Belt: between Jupiter and Mars. Asteroids can collide and get redirected toward Earth. Note the Belt’s size

2nd 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

The resultant Chicxulub Crater is 110 miles in diameter Deep Impact Trailer

Meteor Crater is 2. 5 miles in circumference 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”

Note the two distinct tails: light blue for gas (ion), grey for dust 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:

Comets McNaught 2007 and Hale Bopp 1998

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.

The Oort Cloud is not planar

#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 2 meteors in a shower. Photographed with a camera with an open shutter. What’s in the middle of the picture?

#4: What else is in our solar system?

#4: What else is in our solar system?

To Learn More… About Minor Planets Solar System Sun Meteoroids 951 Gaspra Trojan asteroids Centaurs Astronomical units (AU) Milky Way Small Solar System Body Comet coma Comet tail Comet’s nucleus Elliptical orbits Oort cloud Meteorite 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.

Why isn’t Pluto a “planet”?