The Solar System Pt. 2 Bolides & Behaviors (29.4)

We have many “visitors” from the 3 areas made of space crumbs. ..

Comets: “Dirty Snowballs” Chunks of ice/rock that orbit the sun Their orbital period is anywhere from a few to a few hundred thousand years (if they’re from the Kuiper Belt, or the Oort Cloud) As they approach the sun, their bodies & tails become visible due to solar winds The solar winds partially melt the comet, and cause meteor showers from the debris in the tail to fall.

VIDEO: Most recent visint comet ISON

Asteroids: Chunks of rocky or metallic debris found in a belt between Mars and Jupiter They can be almost as large as some dwarf planets They are thought to be planitessimals that never formed, or shattered planet pieces from an impact

Meteoroid Meteor Meteorite Sand grain to boulder-sized space debris which can fall to earth Usually, it’s debris from a collision or explosion Meteoroids will burn upon entrance into our atmosphere (friction with fluids) and are called Meteors. If they don’t burn up when they land, they are called Meteorites.

Bolide: It’s an extraterrestrial body in the 1-10-km diameter range It impacts the earth at velocities of literally faster than a speeding bullet (20-70 km/sec = Mach 75), explodes upon impact, and creates a large crater. It is a generic term (that could mean meteor, comet, or asteroid)

The KT Boundary Theory (Alvarez Asteroid Theory) It has been theorized that a giant meteor or asteroid could have hit earth in the Yucatan Peninsula about 65 mya. The “ejecta” could have gone into the air, and caused global climate change. This climate change could have caused the extinction of the dinosaurs. Video: KT Boundary Simulation

There is a uniform layer world wide that contains Iridium and Tektites, which indicate the fallout of a major impact from that time period. . .

The Tunguska Event A meteor (20-90 m in diameter) was thought to have exploded in mid-air over Russia in 1908 This explosion knocked over 80 million trees, and was 1000x more powerful than the bomb dropped on Hiroshima

Another one happened in Russia in February of last year! Watch. . .

Arizona Crater 50,000 years ago, there was a collision in the asteroid belt which sent a fragment to earth in Arizona. The diameter of asteroid was only 130 feet, but made a crater 570 feet deep, and 4100 feet across.

Explaining behaviors of Bodies in space: KEPLER Johannes Kepler was a German mathematician and scientist. He explained which bodies in space, particularly planets, behave the way they do.

First Law of Planetary Motion: Every orbit is an ellipse shape Each ellipse has two focal points. . . One is the sun, and one is invisible The farther apart the two focal points are, the higher the eccentricity

Second Law of Planetary Motion: Objects that orbit other objects will go faster at perihelion, and slower at aphelion

Third Law of Planetary Motion: Planets closest to the sun orbit faster than planets farther from the sun.

Kepler’s Theories gave inspiration to some of Sir Issac Newton’s Laws of Motion. . . . The first Law of Motion, INERTIA, seems to affect bodies in space, because there is a lack of forces such as FRICTION and AIR PRESSURE which slows things down on earth.

INERTIA: Objects at rest will stay at rest, and, objects in motion will stay in motion, unless acted upon by an outside force.

Understanding Kepler’s and Newton’s Laws, (and other properties of physics) will help us explore bolides and avoid future impacts!