space, astronomy, stellar nebulas and rotation vs revolution?
this is for a grade 9 science exam,
what is rotation, what is revolution and what is the difference between the two ?
also what is a stellar nebula ?
and please explain the evolution of a star.
thanks so much ::)!
- 1 decade agoFavorite Answer
Rotation of a body is the body spinning around its own axis; like the rotation of Earth.
Revolution of a body is the movement of that body in a closed loop (like a circle or ellipse) around another body; like Earth around the Sun.
So Earth rotates on its axis, and revolves around the Sun.
A star is born from a stellar nebula (primordial nebula), which is just a cloud of gas and dust. This starts to contract under its own gravity and so it eventually heats up under friction. It eventually makes it into a spherical kinda shape and then if it's large enough, it will contract significantly under gravity and start nuclear fusion. It is then a star.
Depending on how big the star is, it will stay on something called the main-sequence for anything from a few tens of millions of years, to thousands of millions of years.
If the star is big (about eight or ten times the mass of the Sun), then when it runs out of fuel it'll turn into a giant star and will go supernova; producing a neutron star or black hole.
If the star is like our Sun, then it''ll eventually become a red giant, and blow off the atmosphere into space. This will leave the very hot core of the star as a white dwarf, and the material of the atmosphere surrounding the tiny star. This is called a planetary nebula.
- 4 years ago
Pale Blue Dot (the most distant image of the Earth), especially along with Carl Sagan's profound ruminations.
- 1 decade ago
revaloution is going around like orbiting the sun and rotation is moving the orbting object spining