ast-com-met Flashcards
largest asteroid and is about 1000 km in diameter
CERES
small rock bodies that have been likened to be flying mountains
ASTEROIDS
T or F
The smallest asteroids are assumed to be no larger than grains of sand
T
T or F
Most asteroids lie between the orbits earth and mars. They have orbital periods of 3 to 6 years
F - between Mars and Jupiter
Asteroids are also called _________, millions of rocks and metal fragments of various shapes and sizes that orbit the sun
Microplanets
First discovered in 1801
Ceres
completes a solar orbit every 14 years
Hidalgo
Trace an orbit similar to Jupiter’s one group in front of the planet another behind it
Trojans
Percentage of the total mass of the asteroids compared with the mass of the moon
15%
The open areas in the main asteroid belt are devoid of asteroids
Kirkwood gaps
A ____________ is smaller than the moon is broken up by a ________ collision and additional collisions yield asteroids that bombard Earth
Planetoid, Giant
T or F
Many asteroids have irregular shapes.
T
Asteroid 951, also called as _________ is probably the fragment of a larger body that was torn apart by a collision
Gaspra
Moon of Asteroid Ida
moon Dactyl
three types of asteroids
Siliceous
Carbonaceous
Metallic
an asteroid 35 miles (56 km) long its surface is marked by collisions with other bodies
Asteroid Ida with moon Dactyl
Most interesting amd unpredictable bodies in the solar system
Comets
pieces of rocky and metallic materials held together by frozen gases, such as water, ammonia, methane, carbon dioxide, and carbon monoxide
Comets
comets that leave their original orbits amd approach the Sun generally settle into new trajectories
Periodic Comets
formed by the nucleus amd the coma
head
front part of the head of a comet
impact front
envelops the nucleus, formed by the gases and dust that it releases
Coma
frozen water, methane, carbon dioxide, ammonia, rock and dust
Nucleus
the trail of suspended gases generates a low intensity, luminous region w/ a bluish color. the gas molecules lose an electron and therefore have an electric charge
Ion tail
suspended dust particles trail behimd the comet, reflecting sunlight and making the luminous tail visible
Dust tail
can measure 62, 000 miles (100, 000 km) or more im diameter
Head
T or F
because of the effects of solar radiation and the solar wind, gases and dust are released from an accelerating comet. the dust particles tend to form a curving tail, which is less sensitive to the pressure of the solar wind. As the comet leaves, the confines of the solar system, its tail coincide once more but they disappear as the nucleus cools down and ceases releasing gases
T
orbits around the sun that are shorter than 200 years
comets with short periods
T or F
Those with a period of more than 200 years travel tens or hundreds of times farther from the sun than pluto
T
T or F
As the comet moves closer to the sun, its tail disappears
F - away from the sun
T or F
close to the sun,the tail reach maximum length
T
glowing head
coma
T or F
the tail of a comet points away from the sun
T
two solar forces are known to contribute to the fact that comets’s tail points away from the sun
Radiation pressure
Solar wind
pushes dust particles away from the coma
Radiation pressure
responsible for moving ionized gases, particularly carbon monoxide
Solar wind
T or F
as a comet moves away from the sun, the gases forming the coma recondense, the tail disappears, amd the comet returns to cold storage
T
T or F
Most comets cannot survive more than a few hundred close orbits of the sun
T
short orbital periods are thought to orbit beyond Neptune in a region called ________
Kuiper belt
T or F
Like the asteroids in the inner solar system, most kuiper belt comets move in nearly circular orbits that lie roughly in the same plane as the planets
T
comets appear to be distributed in all directions from the sun, forming a spherical shell around the solar system called __________
oort cloud
small solid particle that travels through space
Meteoroid
3 sources of meteoroid
1) interplanetary debris that was not gravitationally swept upcbu the planets during the formation of the solar system
2) material from the asteroid belt
3) solid remains of comets that once traveled mear Earth’s orbit
T or F
few meteoroids are believed to be fragments of the moon or possibly mars, that were ejected when am asteroid impacted these bodies
T
Those that do enter the earth’s atmosphere amd burn up are called _________. The light that we see is caused by __________ betweem the particle and the air, which produces heat.
Meteors, friction
results when earth encounters a swam of meteoroids travelimg in the same directiom and at mearly the same speed as earth
meteor showers
T or F
the notable perseid meteor showers occur each year around august 12 amd is believed to be the remains of the comet 1862 III
T
a meteoroid that actually reaches the earth’s surface
Meteorite
meteorites contaim silicate minerals, they are subdivided into chondrites and anchondrites
Stony
meteorites contain a high percemtage of iron and nickel compounds. they are created in the rupture of asteroids
Iron
contains similar quantities of iron, nickel and silicates
Mesosiderites
