Small Bodies in the Solar System

20-3 pgs. 557-561

5/15/14

IN: List the 8 planets in order starting closest to the sun.

Put you DRW on the box

• Mercury Inner Planets• Venus terrestrial• Earth -small, dense,• Mars and rocky

• Jupiter Outer Planets• Saturn gas giants• Uranus -large and made• Neptune mostly of gas

Asteroid Belt

• Asteroids – large chunks of rock that orbit the Sun.

• Sometimes referred to as minor planets.

Asteroid Belt – the region of the solar system, between Mars and Jupiter, where asteroids orbit the Sun.

Comets

• Comets – a small body of ice, rock and cosmic dust loosely packed together.

The Tail of a Comet• A comet’s ion tail consists of electrically

charged particles of dust and gas.

Halley's Comet last appeared in the inner Solar System in 1986 and will next appear in mid-2061.

Halley's Comet is the most famous of the periodic comets and can currently be seen every 75–76 years.

(You don’t have to draw this.)

Meteoroid, Meteorite, or Meteor?• Meteoroid – a very small, rocky body

that revolves around the sun.

• Meteor – the bright streak of light caused by dust burning up.

• Meteorite – a rock that reaches the Earth’s surface without burning up completely.

A “shooting star” is NOT an actual star.

Meteor Showers

Meteoroids and the Moon

Meteorites and the Earth

Objects smaller than about 10 m across usually burn up in the atmosphere.

Meteor Crater• The crater was created about 50,000 years ago.• The object that excavated the crater was a nickel-

iron meteorite about 50 meters (54 yards) across, which impacted the plain at a speed of several kilometers per second (28,600 mph).

•OUT: What would result if a meteorite struck the Earth?