Astronomy Final (Assignment 12)
A few hundred tons of comet dust gets added to Earth daily from the millions of meteors that enter our atmosphere. Estimate the time it would take for Earth to get 0.1% heavier at this rate.
10 ^14 years
Why do asteroids and comets differ in composition?
Asteroids formed inside the frost line, while comets formed outside.
T or F A spacecraft traveling through the asteroid belt has a high risk of being destroyed through a collision.
False
Why was the Shoemaker-Levy 9 impact so important to astronomers?
It dredged up material that gave us our first direct look at Jupiter's interior composition.
The asteroid belt lies between the orbits of
Mars and Jupiter.
What do asteroids and comets have in common?
Most are unchanged since their formation in the solar nebula.
Which have the most elliptical and tilted orbits?
Oort cloud comets
Why does the plasma tail of a comet always point away from the Sun?
The solar wind electromagnetically "blows" the ions directly away from the Sun.
T or F The total mass of the Kuiper belt is greater than that of the asteroid belt.
True
Can an asteroid be pure metal?
Yes, it must have been the core of a shattered asteroid.
What characteristic distinguishes a meteorite from a terrestrial rock? A meteorite is usually covered with a dark crust from burning in Earth's atmosphere. Meteorites contain rare elements, such as iridium, that terrestrial rocks do not. Meteorites have different isotope ratios of particular elements when compared to terrestrial rocks. A meteorite usually has a high metal content. All of the above are true
all of the above
Where are the Trojan asteroids located?
along Jupiter's orbit, 60° ahead of and behind Jupiter
In order to have a comet named after you, you have to
be one of the first three discoverers who report it to the International Astronomical Union (IAU).
About how often does a 1-kilometer object strike Earth?
every million years
Is this mass accumulation significant for Earth as a planet?
insignificant
The combined mass of all the asteroids in the asteroid belt is
less than that of any terrestrial planet.
A typical shooting star in a meteor shower is caused by a ________ entering Earth's atmosphere.
pea-size particle from a comet
Most meteorites are
rocky and primitive.
