A bit of matter that enters Earth's atmosphere and survives to reach the ground is called
a meteorite.
A meteor shower is produced when
the Earth passes through the orbital path of a comet.
The Widmanst�tten patterns found in some meteorites show that the material
cooled very slowly.
A chondrite is a meteor that has
been heated but never very hot.
Currently the most accepted explanation of the Tunguska Event is the explosion of
a stony asteroid just above the surface of the earth.
The Allende meteorite is important because
its composition suggests that it is very old and unchanged from when it formed.
Most of the asteroids orbit the sun in a belt between the orbits of
Mars and Jupiter.
Which of the following could not be caused by the gravitational influence of the planets?
Hirayama families
An asteroid could produce an iron core and a silicate mantle if it
differentiated.
What evidence exists that some of the asteroids were geologically active?
Spectroscopically, Vesta appears to have regions of small lava flows.
The diagram below shows the relative size of Earth's moon and the asteroid 10 Hygiea. Based on this diagram, what is the diameter of 10 Hygiea?
460 km
Uranium, thorium, and the radioactive isotope of potassium cannot supply the heat to melt small planetesimals, yet are sufficient to melt the interior of Earth. This is because these elements
decay slowly, and the heat generated must be trapped by a thick crust if it is to melt the interior.
Uranium, thorium, and the radioactive isotope of potassium cannot supply the heat to melt small planetesimals, but the existence of iron and achondrite (stone) meteorites indicates that some asteroid sized bodies did melt inside. This is thought to be bec
were much more abundant in the solar nebula at the location where the asteroids formed.
An asteroid has an orbital period around the sun of 5.2 years. How far from the sun is this asteroid? [This question requires the use of mathematics.]
3.0 AU
The gas tail of a comet always
points away from the sun.
The short-period comets do not have randomly oriented orbits because
their orbits have been altered by encounters with the planets.
The density of Comet Halley was found to be about 0.2 g/cm3. This implies that Comet Halley
is loosely packed ices with a small amount of rocky material.
Sungrazers are
comets that get very close to the sun.
The type I, or gas, tail of a comet
is streaked and shows emission lines of ionized atoms.
One important way a major impact on Earth is thought to have triggered extinction of many species is because
of changes to the world-wide climate
A large iron asteroid striking the earth can create a(n)
large crater.
The dust thrown up into the stratosphere by the impact of an asteroid can
cool the surface of the earth.
The Cretaceous extinction 65 million years ago is thought to have been caused by
the impact of a small asteroid.
During the Cretaceous extinction 65 million years ago ____ percent of the species on Earth died out.
75
The impact of a large comet with Earth has been suggested to have caused the extinction of the dinosaurs. The impact site of this comet is in or near
Chicxulub Mexico
How is the coma of a comet produced?
Ices vaporize to become gas that form around the comet nucleus.
What characteristic of long period comets suggest they come from the Oort cloud?
Their orbits have random inclinations with respect to the ecliptic plane.
Which of the following is evidence for the connection between comets and meteor showers?
Meteor showers are a predictable, annual event.