Asteroids, Comets & Meteors Module

Introduction to Science

• Welcome to the world of science.

Modules 2nd Grading

• Module 1: Earthquakes & Faults
• Module 2: Earthquakes and Epicenter (Parts 1 & 2)
• Module 3: Earthquakes Waves
• Module 4: Understanding Typhoons
• Module 5: Tracking of A Typhoon
• Module 6: Asteroids, Comets & Meteors

Asteroids, Comets, & Meteors

• Compare and contrast comets, meteors, and asteroids.
• Identify the characteristics of comets, meteors, and asteroids.
• Describe their value in providing scientists with information about the origin of the solar system.

Unscramble Me!

• Asteroid
• Meteoroid
• Meteors
• Meteorite
• Comets

Asteroids, Comets & Meteors (Repeated)

• Review of asteroids, comets, and meteors

Asteroid Characteristics

• Asteroids are small bodies, commonly rocks and/or metallic.
• They have a similar composition to the layers of terrestrial planets.
• Their size is larger than 100 meters in diameter.
• Found within and between the orbits of Mars and Jupiter (asteroid belt).
• Contains numerous asteroids, enough material to form another rocky planet.
• Come in various shapes (elongated, spherical, or irregular).
• Are debris from bodies within the young sun's nebula.
• A nebula is a cloud of gas and dust in outer space.
• Group of asteroids (Trojans) share an orbit with a large planet or moon.
• Jupiter Trojans share the same orbit as planet Jupiter.
• Also found to share an orbit with Mars.
• Near Earth Asteroids (NEAs) are most watched due to the possibility of colliding with Earth.
• 7075 NEAs are found, with 500 to 1000 of them at least 1 km in diameter.
• Asteroid 2012 DA14: Earth Close Approach, Feb. 15, 2013

Impact of Asteroids. Comets & Meteors

• Generate tsunamis.
• Ignite trees and vegetation causing forest fires.
• Shake the earth and create large craters.
• Destroy anything in its path.

Asteroids as a Source of Metals

• Rich in iron, nickel, and other metals.
• Traces of gold, along with rarer minerals such as kamacite, schreibersite, taenite, and troilite.

Describe Me!

• Image of an asteroid.

Observe Object as it moves Towards the Sun

• Something moving out from its body.
• Looks like it shimmers as it moves away.
• Develops two tails as it moves far from the point of origin.

Comets

• A celestial object consisting of a nucleus of ice and dust.
• When near the sun, a "tail" of gas and dust particles pointing away from the sun.
• Origin: Kuiper Belt and Oort Cloud.
• Shape: irregular/varied.
• Chemical composition: dust, rock, metals, ice, frozen gases, ammonia, methane, carbon dioxide, and other organic compounds.

Comet Orbit

• Comet orbit is highly elliptical.
• Orbital Period: 75 to 100,000+.
• Provides clues on how liquid water was formed on Earth.

Comet Parts

• Coma
• Gas tail
• Nucleus
• Dust tail

Halley's Comet

• Appears once every 75 to 76 years.
• Short-period comet/periodic comet.
• Non-periodic - can be more than 200 years or even thousands, or millions of years.

Meteoroids

• Meteoroid- In space- no visible path or trail.
• Meteor- the visible trail or path of the meteoroid as it enters the Earth's atmosphere.
• Meteoroid
• Meteor
• Meteorite

Meteorite

• Hits the earth and survives the impact.

Crater

• Evidence of impact of a meteorite that hit the earth.

Composition of Meteorites

• Stony (most common)
• Iron-nickel (less common) - Higher density.
• Stony Iron (classified as stony iron)

Table 1: Characteristics of Comets, Meteors, and Asteroids (Summary)

• Summarizes the origins, shapes, chemical compositions, orbits, orbital periods, and importance of comets, meteors, and asteroids.

Thank You for Listening

• Concluding message on the topic.