Ask A Scientist General Science Archive

Question:  How did the Earth appear in the sky? ---Ashley

Answer:
Ashley-
 
If you mean, how did the earth form, the answer is gravitational
attraction.  Many years ago--about 4.6 billion years ago, in fact--
particles and dust in the solar system accumulated together to
form the earth, the sun, and the other planets.  The reason that
the particles and dust accumulated together is their
gravitational attraction for each other.

Normally, when we think of gravity, we think of objects being attracted
to the earth.  The gravitational attraction of the earth is the most
obvious because the earth is the heaviest object
around, and therefore has the greatest gravitational attraction.
But even small objects have some attraction for each other.  Before
the earth, the sun, or the other planets existed, there were only
small particles in the solar system.  These small particles
attracted each other until larger objects started to be formed.
As more and more material accumulated, these larger objects developed
into the sun and the planets, including the earth.
-Grant