Asteroid

Comets are, in the phrasing of astronomer Fred C. Whipple, "dirty snowballs", that is, they are made of ices (CO2, H2O, frozen NH3 and CH4) with a mixture of various carbons and silicates to make a lump. Most comets travel in extremely elongated orbit, and spend most of their time far from the Sun (if they din’t, the ices would evaporate, and you are left with a meteor shower).
Asteroids are chunks of rock and metallic material that can be nickel-iron (about 20%), silicate (about half), a mix of nickel iron and silicate (20%) or carbonaceous material (10%). While the majority of asteroids are found between Mars and Jupiter, there are many known that fall outside those limits. Some asteroids are known to have their own very small moons.

Well it burns up when it hits the atmospher it seems like it would burn much more readly than a rock. There might be a lot of alien crap up there in space even one alien after a month is a lot of crap what if there where hundreds compounded by months to years in space travel. lets say the alien did not flush every time he save up his sewer then decided to dump it all at once a giant ball of fecal or asteroid of crap coming at a planet. Do we half to take that sort of crap from aliens? It could ruin the whole planet.

Careful what you ask for… :>

In fact, surveys of "microimpacts" (small craters left in the shuttle, for instance, from man-made debris in orbit) have revealed that a sizable fraction of the dust-mote sized impactors were, in fact, frozen particles of human feces.

Apparently it was standard practice for a long time for space station inhabitants (…which basically meant the Soviet Union space station program…) to just dump their waste overboard.

I can’t find any documentation on this in a quick search; I’ll leave the below link to get you started. That, and your apparent interest in the subject. :>

Comets are balls of ice from the Oort Cloud outside of the Solar System. they travel on highly elliptical orbits down into the solar system, towards and around the Sun, and then back out again. But asteroids are of three compositions and generally remain in the Asteroid Belt between Mars and Jupiter.

You’re not alone in being confused by these three. Asteroids and comets are similar, in that they are medium sized bodies which orbit the Sun, but different in many ways.

Comets are mostly "dirty snowballs": a mixture of dust and ice, which sublimates when they get close to the Sun, causing them to develop long tails. They usually have very eccentric orbits which take them very far from the Sun.

Asteroids are made of rock, and have fairly circular orbits around the Sun.

Meteors start out as meteoroids, basically very small versions of asteroids, often debris from an earlier comet. When they encounter the Earth’s atmosphere they vaporize and cause the atmosphere to glow briefly, what we call a meteor or a "shooting star." Unlike asteroids and comets, meteors are very close to us, roughly 100 miles up in the atmosphere, so they appear to move very quickly. They shoot across the sky quickly and vanish. Mostly. A few of the larger ones don’t vaporize completely, and actually fall to Earth, where they are called meteorites. So you have a meteoroids in space, briefly becoming meteors in our atmosphere, and sometimes surviving to become meteorites on Earth.

how does the energy in space effect asteriods?? If at all??

Energy from both the Sun and deep space does affect asteroids in several ways. High energy radiation darkens the surface of asteroids through a process called space weathering. It can also break molecular bonds in the surface materials, usually a loose covering of rocks and dust called regolith, altering it’s chemical properties. Cosmic rays slash into the surface, leaving traces in the form of cosmic ray tracks. These particles also can transform an atom into a different element, or change it to another isotope of the same element. The surface of asteroids absorbs a lot of energy from the Sun and re-radiate it as heat back into space. Electromagnetic radiation does exert a minute push on objects in space, and if an asteroid radiates heat preferentially in one or more directions, it’s orbit will slowly change over time. All small asteroids are irregular in shape and because of this, they will radiate more heat in some directions rather than others, which can speed it up, slow it down or even affect it’s rotation. Some asteroids also get very close to the Sun, whose intense radiation can heat the asteroid until it glows red hot. If there’s any water or other volatile compounds present in an asteroid, energy from the Sun will drive it off into space the same way ices and gases are driven into space from a cometary nucleus. Some near Earth asteroids are undoubtedly dead comets who were baked dry by the Sun ages ago, and now wander around the Sun as asteroids with a surface blacker than a blackboard.

Why haven’t we built small robot’s (minning machines) and sent them into the asteroids to harvest the ore there and then use it to make objects for consumption on earth, or to make more robot’s to mine more asteriods?

because the cost of building robots and sending them out to space to mine these asteriods, then transporting the ore back to earth is more than the ore itself. We will begin to harvest space junk when space travel becomes cheaper.