(SEM1Q1, SCI) 4.2 - Asteroids

What are other names for asteroids?

minor planets; planetoids

What are asteroids?

rocky and metallic objects that orbit the sun but are too small to be planets

What happens to asteroids with diameters of 30 miles or less?

they no longer have a spherical shape

What are planetoids?

larger forms of asteroids

What is the Main Asteroid Belt?

region between Mars and Jupiter where most asteroids orbit

What is the largest belt asteroid by diameter?

Pallas

What are trojan asteroids?

asteroids in the orbits of Jupiter and Neptune or in the Kuiper Belt

What are near-Earth asteroids?

asteroids that are near Earth

What are some near-Earth asteroids that cross the orbits of Earth and Venus? (2)

Apollo, Athena

What is the largest asteroid discovered?

Ceres

Who discovered Ceres?

Giuseppe Piazzi

How long do most asteroids orbit the sun?

3-8 years

What is the shape of an asteroid's orbit?

elliptical

What type of surfaces do asteroids have?

dark surfaces

What elements are found in asteroids? (4)

carbon, iron, nickel, iridium

Who were the first to suggest that the unusual concentration of iridium layers in different parts of the world? (2)

Luis Alvarez, Walter Alvarez

In which layer of the Earth is Iridium abundant in? (2)

mantle, core

What is the Alvarez Theory?

An asteroid slammed into the Earth, causing debris and water to be thrown up and block sunlight. This made plants and animals extinct, eventually the dinosaurs too.

What do you call the period dinosaurs reigned?

Cretaceous Period

What do you call the period mammals took over?

Tertiary Period

Which asteroid was believed to have been the one that ended the lives of the dinosaurs?

Chicxulub in Mexico

What is the name of the small moon of asteroid Ida discovered by Ann Harch?

dactyl