HW8

A  comets are not gravitationally bound to our Solar System

B  comets burn quite rapidly, using up all their fuel within a few decades

C  most comets only pass close to the Sun 2 or 3 times, and then they disintegrate

D  orbits of comets are highly eccentric and their semimajor axes are large

E  it is impossible to tell when most comets will return close to the Sun

A  A protrusion out of one end of the potato-like comet nucleus.

B  Gas, dust & gravel left behind in the comet’s orbital path.

C  It is ions blown out by the Sun’s solar wind.

D  A bright gas cloud released by sublimation on the Sun side of the comet.

A  Is about as large as the planet Mercury

B  Is massive enough to substantially affect the orbit of Uranus, which led to its discovery

C  Has a nearly circular orbit around the Sun, due to its interactions with other objects in the vicinity

D  Has a density intermediate between that of the terrestrial planets and the giant planets

E  Has no moons

A  The iron/nickel asteroids are the most common kind.

B  There is no evidence that the material from which asteroids formed was ever part of one or more larger bodies that could have experienced differentiation.

C  The mass of all the asteroids together is roughly that of the Earth.

D  The main asteroid belt if probably debris that would have formed a planet had Jupiter not prevented it.

E  All asteroids appear to be quite solid objects, rather than collections of smaller rock held together by gravity.

A  devastate an area no larger than 30 km in diameter

B  bring an end to human civilization, or at least destroy much of the human race

C  only crush a car, if one happened to be at the point of impact

D  create a crater more than 300 km in diameter, but have little or no effect on the rest of Earth and its inhabitants

E  burn up in the atmosphere before reaching the ground

A  eclipse

B  shooing stars

C  meteor shower

A  Blackhole

B  Asteriod

C  Planetesimal

D  Comet

A  Nucleus

B  Tail

C  Coma

A  trans-Neptunian objects (TNOs)

B  dwarf planets

C  terrestrial planets

A  Oort Cloud

B  Halley’s Comet

C  Great Comet

A  meteorite

B  asteroid

C  meteor