Question

How canwesay that our earth is still in the process of formation?

Answer 1

The first and most widely accepted theory, core accretion, works well with the formation of the terrestrial planets like Earth but has problems with giant planets. The second, the disk instability method, may account for the creation of these giant planets. 

Scientists are continuing to study planets in and out of the solar system in an effort to better understand which of these methods is most accurate.