Exam 12: Dwarf Planets and Small Solar System Bodies

Pluto is composed mostly of rock.

The nucleus of the typical comet is approximately __________ in size.

In 1994,dozens of fragments of Comet Shoemaker-Levy 9 collided with

Consider a meteoroid with a diameter of 10 cm and a mass of 2 kg that hits the Earth head-on while traveling at a speed of 25,000 m/s.How many times larger or smaller is the meteoroid's kinetic energy compared to that of a typical train whose mass is and speed is 25 m/s?

A recent estimate finds that approximately 800 meteorites with mass greater than 0.1 kg strike the surface of the Earth each day.If a house covers an area of roughly then what is the probability that your house will be struck by a meteorite in your 100-year lifetime? Note that the radius of the Earth is 6,400 km.

The surface of the dwarf planet Eris has very high albedo and is covered with

Comets have highly eccentric orbits,with eccentricities of being common.Suppose a certain comet has an eccentricity of 0.99.If the semimajor axis of its orbit is 2,500 AU,what will be its distance at perihelion and at aphelion? Is this most likely a Kuiper Belt object or an Oort Cloud comet? [Note: For an ellipse, is the distance from one focus to the farther edge of the long axis and is the distance from the same focus to the closer edge of the long axis.]

Give the definitions of meteoroid,meteor,and meteorite,and clearly explain how they differ.

The most common type of meteorites found are iron meteorites.

Most asteroids are closest in shape to

Consider a small comet nucleus,whose diameter is 1 km and mass is ,hitting the Earth head-on,traveling at a speed of 1,000 m/s.How many times larger or smaller is the comet's kinetic energy compared to that of a typical train pulling 20 boxcars whose total mass is and speed is 25 m/s?

How is it possible for the tail of a comet to actually move ahead of the comet itself?

What does the existence of M-type asteroids tell us about their origin?

The most common type of meteorites are

In its 1986 trip around the Sun,it was estimated that Comet Halley lost approximately 100 billion kg of material.The total mass of the nucleus was estimated to be .Assuming the mass loss rate is constant with each passage,and assuming the nucleus remains intact until there is nothing left,how many more times will we see Comet Halley? Explain why your answer is an upper limit.

Eris and Ceres are examples of

Name three properties of the dwarf planets Pluto and Eris that are similar.

The meteoroids in the Orionid meteor shower,which occurs every October,come from

The minimum size of a meteoroid that is capable of surviving its passage through the Earth's atmosphere and hitting the ground is about as big as

Most asteroids are