Question

how was the earth made and is mars really live able

Answer 1

earth made by our God, The Earth was created 4.54 billion years ago when part of the Sun's accretion disc agglomerated into a spherical body. At that time, shortly after the birth of the Sun itself, the solar system's matter was much more scattered around, in the form of asteroids and dust rather than planets. This "matter cloud" has been called a Bok globule, and these globules have been observed in other parts of the Galaxy. Scientists have determined the age of the Earth relatively precisely using isotope dating of the world's oldest rocks.

It is not known precisely what mechanism caused the precursor of the solar system, a gaseous nebulae, to form into the Sun and its attendant accretion disc. It may have been shockwaves from a nearby supernova, or simple gravitational collapse due to a threshold density. Whatever the cause, when enough density gathered in the center of the gas cloud, it ignited to become the Sun. The resulting heat banished volatiles (materials with low melting points) to the outer solar system, while leaving rocky bodies, like the Earth, Mercury, Venus, and Mars, in the inner solar system, where they could grow.

Answer 2

then Mars....really Mars contain some minerals which needed to human to survive so it seems can be liveable...but you know that in Mars there's no atmosphere anymore, so there's no something to filter ultraviolet ray from the sun....thus Mars can't be liveable..

Answer 3

Well, ultraviolet radiation for the sun could be blocked by moving beneath the surface of the earth. Gamma Rays from exploding stars that are typically blocked by the allen belt, ie the magnetic ring around the earth, is probably much more crucial. If I remember correctly, one of the main reasons Mars lost it's atmosphere is due to it's core cooling/solidifying which allowed the solar wind to blow the atmosphere away.

Answer 4

it seems doubt that 'mars has no atmosphere' , I think it had covered with methane mostly....

Answer 5

one interesting thing I heard recently is that without the moon to balance out the Earth's rotation, life minght not have been possible, or at least gotten to the diversity and complexity it has today. without the stabilizing effect, the spin axis would be changing a lot, so land masses would be subjected to extreme climates much more often (think ice ages coming and going much more rapidly, extreme conditions, etc.)