Bell Work: 1.What is the color of the sun? 2.What is the average temperature of the sun? (Use your text book to help you.) 3.Define: comet, asteroid, and meteoroid.

Comets, Asteroids, & Meteors In addition to planets and moons, the solar system contains many other types of objects, including comets, asteroids, and meteoroids.

Comets A comet is a small body of ice, rock, and cosmic dust loosely packed together. Known as “dirty snowballs.” When a comet passes close enough to the sun, solar radiation heats the water ice so that the comet gives off gas and dust in the form of a long tail. nucleus Ion tail Dust tail

Comet Orbits The difference between the orbit of a planet and the orbit of a comet is that a comet's orbit is highly elliptical and a planet's orbit is only slightly elliptical, but more circular. The comet’s ion tail always extends away from the sun. This is because the ion tail is blown away from the sun by the solar wind.

When the comet Shoemaker-Levy 9 broke apart and fell into Jupiter, some of the fragments generated explosions that produced fireballs larger than Earth.

Asteroids Asteroids are small, rocky bodies in orbit around the sun. Have irregular shapes Most asteroids orbit the sun in a wide region between the orbits of Mars and Jupiter, called the asteroid belt.

Types of Asteroids Outer region of the asteroid belt = dark reddish brown to black surfaces A little closer to the sun = dark gray surfaces Innermost part of the belt = light gray asteroids Examples: Hektor, Vesta, and Ceres

Meteoroids A meteoroid is a small, rocky body orbiting the sun. Meteoroids are similar to asteroids, but they are much smaller. In fact, meteoroids probably come from asteroids.

Meteoroids If a meteoroid enters Earth’s atmosphere and strikes the ground, it is then called a meteorite. Stony, metallic, and stony-iron are the three major types of meteorites. It travels at such high speeds that it heats up and melts. As it burns up, the meteoroid glows red hot and gives off an enormous amount of light. From the ground we see a streak of light or shooting star. The bright streak of light caused by a meteoroid or comet dust burning up in the atmosphere is called a meteor.

Meteor Crater Planets and moons that have no atmosphere have many more impact craters than those that do have atmospheres. Earth’s atmosphere acts like a shield.

In 1954, Mrs. E. Hulitt Hodge, of Alabama, was struck by a meteorite as she was taking her afternoon nap. Bruised, but not badly injured, she is one of only two people known to have been struck by a meteorite.