oxygen

China
May 9, 2012 9:20am CST
There is oxygen in Mars. oxygen exists in the atmosphere and the shell. but why is there more oxygen in the earth's atmosphere than in the Mars? is it mainly caused by plant photosynthesis? is there other reason? the temperature?
5 responses
@MrGhost (550)
15 Apr 13
It is due to 'escape velocity'.
• India
14 Jul 12
Hi friend, Earth is the best place for living than any other planets, so only we have lot of oxygen here compared with Mars, even scientists find that there is possibilities available to live in the Mars, we don't have more comfortable life like earth in the mars
@owlwings (43910)
• Cambridge, England
9 May 12
Mars is considerably smaller than the Earth so many gases which Earth can retain are lost from the atmosphere of Mars. A great deal of Mars' oxygen is also locked up in oxides in the rocks. Earth's levels of free oxygen are also maintained by plant photosynthesis.
• Pasay, Philippines
15 May 12
if there's no oxygen then why the planet gets rusty? That's oxidation process in irons, right? LOL Hope to protect this planet first before getting another planet with the same earth components. Well, prevention is better than "remedies".
@lady1993 (27224)
• Philippines
14 Jul 12
I think it is because of the plants here, since living things live here, then there is more carbon dioxide produced and oxygen would never run out... as long as the entities important can still continue the cycle.