Can an Asteroid Start out as a Comet?

Question : Comets are made of ice. And asteroids are made of rock, so if a comet's ice melts and it has a rocky core leftover does it become an asteroid?

Answer: 

You're absolutely right..!we know of many objects identified as Asteroids which have suddenly developed comas and tails. It is thought that a good percentage of asteroids are likely to be dead comets. Note that the only difference between calling an object an asteroid or comet is the presence of a Coma or Tail. Even 'dead' comets can start their activity all over again. The ices that sublimate to generate the coma and tail may have been hidden behind a tar like space 'rust' that has slowly weathered away to reveal more ices. We anticipate that the core of all asteroids will contain at least some ices and not be just barren rock.

why does the sun keep burning if it is so cold in space?

Question Why does the sun keep burning if it is so cold in space? How come if there is so much cold in space it does not affect the sun? Is the sun on fire ?  

Answer :

The Sun is not on fire. It's heated from within by nuclear fusion at the core, which produces both light and heat. As you move away from the core, it does get cooler, from 15 million degrees at the center to only about 5,000 at the surface (and then it jumps back up to a million in the chromosphere, probably due to magnetic reconnection on the surface). Because of two simple reasons: Stars are powered by nuclear fusion. Not combustion. But if they were powered by combustion and there would be enough oxygen in space the temperature would still not affect them since "cold weather" doesn't leave much of an impression to combustion either. Your campfire burns happily at -40C. It just might not produce enough heat to stop you from becomming an ice block.As said above, Nuclear Fusion keeps the sun Burning you could say. But as to space being cold is a matter of opinion. Since there is such a small ammount of heat transfer in space it would take a long time for you to become cold if you were directly exposed to space and could survive it.

Do Planets Explode Or Implode Like Planets?

Neither , Planets (unless impacted) just stay the way they are , Planets are generally a stable body . A large asteroid (or comet or planetoid) could destroy a planet, for that matter another planet could destroy a planet, a black hole could or a neutron star, Many things could, however those are all unlikely sources of planetary destruction.

How Many Years Of Life Are Left For Our Sun ?

Scientists believe the sun has about 4.5 billion years left to the sun.technically the sun will live as a white dwarf for many more billions of years but most people do not consider that to be living, instead they consider the sun to die at about ten billion years, when it collapses into a white dwarf.

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