What had to be invented before we could discover saturn and neptune?

What effects result when there is an impact between earth and an asteroid? check all that apply. a.massive flooding. b.extinction of many life forms.c.major earthquakes change in average global temperature.d. giant dust cloud

Which of the following list the divisions of the geologic time scale in order from longest to shortest

Which form of pure carbon is so hard that it can be used in cutting tools?